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Cross Generational Simulating/Comparisons

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  • bchaikin@aol.com
    Over at apbr_analysis, we ve discussed the cross generational comparison of players and teams and I think we reached the conclusion that such comparisons are
    Message 1 of 29 , Jan 23, 2003
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      Over at apbr_analysis, we've discussed the cross generational
      comparison of players and teams and I think we reached the conclusion
      that such comparisons are difficult or impossible to ground-truth. 
      There were some dissenters who we may just kill off. 

      now why would you want to go and do that? if everyone agreed with you, what fun would these discussion groups be?.....

      and who is "we"? i certainly don't agree with any conclusion stating that directly comparing players over the past 40-45 years in the NBA is "...difficult or impossible...". on the contrary, i find it fairly easy......

      i've read every single post on both discussions groups since this discussion on "...are the players of today better than the players of yesterday..." and, more exactly, "...how could we simulate cross-generational pro basketball..." began a number of weeks ago, patiently waiting for any kind of proof or evidence in terms of some discussion stating why players cannot be compared directly over the past decades, and while i have heard a number of people state it can't, or shouldn't be done, i haven't seen any definitive reasons why. i remain wholely unconvinced by the arguements presented so far, and would love to debate any discussion that actually trys to explains why it can't be done accurately using the actual stats...

      i've posted a number of similar questions to the group concerning this exact topic and they have to this point been completely ignored, such as:

      "...if players over the past 40-45 years (actually since the mid to late 1950s) cannot be compared directly, explain where the cutoff is, or cutoffs are, and why?..."

      can players be compared directly (or simulated directly against, using actual statistics) from the 1990s to the 1980s, or from the 1990s or 1980s to the 1970s, from any of those 3 decades to the 1960s, and from any of those four decades to the mid to late 1950s. if not, where does any cutoff exist and why?..."...

      if players/teams from the 1990s can be compared directly with players/teams from the 1980s, why? if not, why not? what is the reasoning, or evidence? same for the other decades? can players from the mid to late 1950s be compared directly to the players of the 1960s? if so, why? if not why not?...

      someone mentioned in previous postings a study by paleontologist stephen jay gould in his book "full house" (1996) where he talked about the disappearance of the .400 hitter in baseball as being due to a decrease in variation of batting averages (whose mean he states was stable over that same time) over the 130 years of baseball, and that that decrease in variation implys a general improvement of performance in the game of baseball over time, and that person posed the question of whether a .260 hitter in i think 1890 was the same as a .260 hitter today (gould would say no). since gould did a somewhat statistical study using standard deviations, and that was attempted by others here in this discussion group to try to find if an analogous situation in pro basketball existed using FG%s, lets look at what gould did, keeping in mind what we want to use his statistical evidence for - to ask can we compare directly basketball players of today to yesterday, are the players of today better than those of yesterday, and if so why, and can we simulate games between teams/players of today to yesterday, and if not where is any cutoff point...

      also i do not wish to convert this basketball discussion group to a baseball discussion group, but as i have yet to see a written source for a discussion about historical basketball as we are attempting to do, i'm guessing it is a good starting point...

      i've read all of the chapters in gould's book about his baseball batting average study (chaps 7-11, pages 77-132), and for those of you that haven't, here are some excerpts. since he has quoted bill james, i will also add in quotes from james and my own comments. keep in mind that while i like what he has shown, and it is a nice approach using statistical analysis, it has some flaws as this pertains to our discussion:

      "...Where else can you find a system (i.e. pro baseball) that has operated with unchanged rules for a century (thus permitting meaningful comparison throughout), and has kept a complete record of all actions and achievements subject to numeration?..." (page 78)

      "...The extinction of .400 hitting really measures the general improvement of play in professional baseball...." (page 79)

      "....More ink has been spilled on the disappearance of .400 hitting than on any other statistical trend in baseball's history. The particular explanations have been varied as their authors, but all agree on one underlying proposition: that the extinction of .400 hitting measures the worsening of something in baseball, and that the problem will therefore be solved when we determine what has gone wrong...." (page 80)

      "....The extinction of .400 hitting measures the general improvement of play...." (page 81).

      "....For almost every sport, the improvement in absolute records follows a definitive pattern with presumed causes central to my developing argument about .400 hitting. Improvement does not follow a linear path at a constant rate. Rather, times and records fall more rapidly early in the sequence and then slow remarkedly, sometimes reaching a plateau of no further advance. In other words, athletes eventually encounter some kind of barrier to future progress, and records stablize. Statisticians call such a barrier an aymptote; vernacular language might speak of a limit. In the terminology of this book, athletes reach a "righ wall" that stymies future improvement....." (page 93)

      "....For reasons never determined, batting averages declined steadily throughout the 1960s, reaching a nadir in the great pitchers years of 1968....." (page 104)

      "…that .400 hitting might have disappeared as a consequence of shrinking variation around (a) stable mean (i.e. .260 hitting)…"(page 105)

      "....the higher the value of the standard deviation, the more extensive, or spread out, the variation…"(page 106)…

      ".....variation (in baseball) decreases steadily through time, leading to the disappearance of .400 hitting as a consequence of shrinkage at the right tail of the distribution…"(page 107)

      "....we note in particular that (
      while looking at a graph of yearly averages of standard deviations of batting averages for regular players - starters - from 1875-1980), while standard deviations have been steadily dropping and irreversibly (1875-1980), the decline itself has decelerated over the years as baseball has stabilized - rapidly during the 19th century, more slowly during the 20th, and reaching a plateau by about 1940…"(page 107)

      i know that as you read this you can't see his graph, but what it plots is standard deviation in batting averages versus year, from 1875-1980, and while the decline (decrease in variation) is evident from 1875 to the mid 1930s, there is no decline (no change in variation) from the mid 1930s to 1980s, a span of some 45+ years, and if you extrapolate it to today (2003), i'm sure you'll see the same pattern, meaning the trend of no variation is for 65+ years...

      "....this analysis has uncovered something general, something beyond the peculiarity of an idiosyncratic system, some rule or principle that should help us to understand why .400 hitting has become extinct in baseball....." (page 110)

      ".....400 hitting disappears as a consequence of shrinking variation around a stable mean batting average...." (page 111)

      ".....the shrinkage of variation must be measuring a general improvement of play...." (page 112)

      "....complex systems improve when the best performers play by the same rules over extended periods of time. As systems improve, they equilibrate and variation decreases...." (page 112)

      ".....as play improves and bell curves march toward the right wall, variation must shrink as the right tail...." (page 116)…

      "....the disappearnce of .400 hitting marks the general improvement of play...." (page 120)

      "....a model that posits increasing excellence of play with decreasing variation when the best can no longer take such numerical advantage of the poorer quality in average performance..." (page 120)

      ".....I do recognize that some improvement might be attributed to changing conditions, rather than absolutely improving play…older infields were apparently lumpier and bumpier thatn the productions of good ground crews today - so some of the poorer fielding of early days may have resulted from lousy fields rather than lousy fielders. I also recognize that rising averages must be tied in large part to great improvements in the design of gloves, but better equipment represents a major theme of history, and one of the legitimate reasons underlying my claim for general improvement in play…"(page 121)

      up and to this last quote i've given you an idea of what gould is saying, but re-read this last quote. basically what gould is saying is that, yes, i admit that while the rules of the game have remained essentially the same, that the conditions in the game have indeed changed (not to mentioned changes in stadiums, favoring either the hitters or pitchers as bill james stresses but gould ignores) over the years, but guess what - i don't care, they actually legitimize my point, i.e.. that doesn't change anything. he is saying that yes conditions of the game have changed, but he does not admit that that may be part of the reason, if not a major part, for players improving over the years....

      this is very important for our discussion for basketball, where the conditions of the game haven't changed very much - compared to baseball - over the same time period of the mid 1950s to today, and people like bill james shows that the stats reveal that the players aren't any better (or worse) in baseball. example: basketball courts haven't changed size like fields have in baseball, and thus that avenue of skewing stats doesn't exist in basketball....

      remember above where gould's graph showed batting average standard deviation hadn't changed from the mid-1930s on? gould's arguments take into account the entire time period of 1875-1980, but it shows little if any difference from the mid 1950s to today. in basketball we are looking at the same time period, the mid to late 1950s to today, where the environment for athletes was the same for professional basketball players and professional baseball players. not many players in both sports lifted weights in the 1950s, travel in both sports was similar, mostly by train, blacks were just starting to be integrated into baseball and shortly after into basketball, treatments for physical injuries were the same, etc...

      so what gould is looking at is the entire process (the numbers), and not the players as a definitive group, i.e. are players better today than yesterday. he surmises this, but he is in fact looking at baseball as a whole, a single process, and not at how the conditions of the game over the years has affected the players (more accurately the players statistical output as gould is looking at the stats), unlike bill james, who has looked at the changing conditions of the game thru the years and how this has affected player statistical output, and has attempted to normalize numbers based on his findings...

      gould quotes james a number of times in his book, but its evident from reading these
      five chapters that he hasn't read james thoroughly. i think most would agree that bill james has probably done more for the understanding of baseball statistics over the years than has gould (and possibly more than anyone), especially when it comes to comparing players from different eras, and james has gone into detail about how the conditions of the game has changed (stadium size, lefty/righty, rule changes and outside influences) over the years...

      obviously gould hasn't read james most recent historical baseball abstract book (an update to his mid1980s book), kind of hard when six feet under, but the vast majority of the book is the same, so gould should have read all of james' mid-1980s edition.

      as an example, when discussing the difference in eras (as shown by the stats), james says (2001 historical abstract, page 481) when comparing eddia collins and rogers hornsby, "...the relationship between 1909 baseball and 1929 baseabll is like the relationship between 1960s and 1990s baseball. many hitters in the 1990s have better numbers (stats) than any hitter posted during the 1960s, not because the players have gotten better, but because the conditions of the game have swung in the hitters favor. same thing back then: many hitters from 1929 have better numbers than any hitter in 1909. this doesn't prove that they were better hitters...

      when discussing the poor hitting number of the 1960s, james says (page 258, same book) "...the most important causes of the 1960s game (poor hitting great pitching), i believe were stadium architecture and the lack of an enforcement mechanism regarding the height of the pitcher's mound. the newer parks in that era moved the fans further away creating more foul territory (i.e. more foul outs and lower batting averages - my words). almost every change in ballparks between 1930 and 1968 took hits out of the league...

      so how does this relate to basketball? i contend that unless someone can show me how the game is different, condition wise, between the years of the mid to late 1950s to today, as james has done for basketball, that like gould we can look at the numbers directly. gould only looked at the numbers and james has shown that this needs refinement based on how the comditions of the game have changed. i would love to see some arguments on how conditions in basketball have changed from the mid-to-late 1950s to today, thus having the stats affected in some way, such that the numbers cannot be compared directly, but i have yet to see this...

      in previous posts i have listed some of the major stats by five year periods since the mid 1950s, and shown similarities, again stating that the game has remained basically the same as a process over that time period. if you were to look at basketball from the late 1800s/early 1900s i would agree there's major differences, that the conditions of the game were vastly different, but unfortunately we can't even compare them because the stats are not available. baseball was quite different in the late 1800s compared to today...

      ".....Wade boggs would hit .400 every year against the pitching and fielding of the 1890s, while wee willie keeler would be lucky to crack .320 today...." (page 125)

      this is a preposterous statement. what would wade boggs have done when he got sick, or just a cold, back then? how about a pulled muscle? a broken finger? there were no antibiotics for simple cures for common ailments back then, no trainers, no x-tays for pictures even if you thought you had a broken bone. poorer nutrition, longer train rides (in terms of time spent) than plane rides, no weight training, you name it. gould is looking at this as being one single process and not taking into consideration the conditions of the game, which james has shown can be used to successfully normalize the eras (if you believe what james has done, which i do)...

      the bottom line is that boggs was one of the very best of his time and keeler was one of the very best in his time. like bill james points out, you look at how the people of the time revered the players, especially his peers, and both were the very best of their time according to their peers. its my contention that the players in the NBA in the mid to late 1950s are as good basketball players as the athletes of today - the best of their time playing at the highest level available. based on that i believe you can simulate the teams/players from the late 1950s and early 1960s to those of today directly, and challenge anyone to dispute this with some sort of statistical evidence...

      and as i state this remember that to simulate players of that time period of the late 1950s early 1960 to the players of today, you simply can't say pettit and yardley and  schayes couldn't play today because the players are bigger and stronger today, you also, if expected to be believed, have to consider today's players playing a season or two back then in that time period, where the players would not have the medical advances of today available, the scores of trainers, coaches, tv commercials and rap albums, whatever...

      until a study is done similar to what gould did, showing the standard deviation of not just FG% but a multitude of other stats have had convincingly shrinking variation thru time from the mid to late 1950s to today in pro hoops i certainly do not see any evidence that the game has changed to the point that the players cannot be compared directly based on their stats...

      ".....As the best batters sacrificed their .400 averages because variation declined while average play improved, the best pitchers lost their earned run averages below 1.50 because ordinary hitters became so good...." (page 126)

      pitchers of the 1900s and 1910s had extremely low ERAs because that was the style /condition of the game at that time, as discussed by james a number of times...

      ".....For some reason that no one understands, pitching took a dramatic upper hand that year....." (1968),

      again for someone who quotes bill james alot its apparent gould hasn't read him enough...

      "....Symmetrically shrinking variation in batting averages must record general improvement of play for two reasons - the first because systems manned by the best performers in competition, and working under the same rules through time, slowly discover optimal procedures and reduce their variation as all personnel learn and master the best ways: the second because the mean moves toward the right wall, thus leaving less space for the spread of variation…as variation shrinks because general play improves, .400 hitting disappears as a consequence of increasing excellenece in play...." (page 128)

      this is gould's conclusion. but how does it stand up to the test of time with barry bonds recent slugging percentage marks, and the complete repeated wipeout of babe ruth and roger maris's home run records by mcgwire, sosa, and bonds? as james would say, its the conditions of the game that are different, not the players...

      If cross-generational comparisons are all you are concerned with,
      yeah, I agree, stats are difficult to use.  Team wins and losses are
      about the only things comparable through time (and there are
      arguments on even that having to do with strength of the league).

      i have yet to read bill james book on win shares, but will soon,to try to see if a system can be made comparable to basketball. you would tend to think yes because there are so fewer players that account for the results of the games in basketball, bit that is merely an assumption...

      The better approach is to have some real team win-loss thing to
      calibrate against (MikeG phrased as "correlating contributions to
      team success").  That is difficult (not impossible) because, when the
      Bulls lost Jordan (the first time), they didn't decline much, but
      when the Spurs lost the Admiral, they dropped like a rock.  When MJ
      came back the Bulls were the best team in history, but they also got
      Dennis Rodman, so you have to account for him.  Doing the whole
      assessment of how a team does leads to an intractable problem of
      sorting out who is responsible for what by when certain players are
      in the lineup.  Jeff Sagarin tackled the problem from a pretty
      scientific angle and came up with Andrei Kirilenko as the 2nd best
      player in the league last year, which didn't quite pass the laugh (or
      smell) test.


      i haven't tried this yet, and haven't seen anything in print yet simlar to what james does for baseball (win shares), so i don't know if it would be difficult. i haven't seen sagarin's system - is it online and available to be critiqued?

      Plus/minus in the NBA is, I think, somewhat valuable.  It gets at exactly what I'm interested in -- how well does a team perform with different individuals in the game. 
      There are definite correlation problems with it in that some decent players only play with other bums, so they don't look as good.  Also, the fact that Jeff Sagarin's method used this information to come out with individual plus/minus ratings (isolating effects of players as best as possible) that seemed implausible, makes me question them.  BobC has never liked them.

      its not that i don't like them, its that they are meaningless, like the ubiquitous AST/TO ratio which tells you next to nothing (there are TOs that have nothing to do with passing, this is used because its simple to calculate, and some time ago someone gave it credence). the +/- ratio is an individual stat not comprised of anything an individual does. in hockey the supposition was that since the majority of the time players are on the same lines, and that the majority of skaters only play about 20 minutes or less of every 60 minute game, that the +/- could tell you something....

      well in basketball the best players play upwards of 75%-80% of each and every game
      and i don't care who you are - you could be an all NBA player or the best in the league, but if you play on a 20-62 team you will have a lousy +/- ratio, and even if bruce bowen has a great +/- ratio because his teammates are duncan, robinson, and the rest of the 58-24 spurs, it doesn't mean he is a great player. he could have a great +/- ratio but you put him on a different team and this one trick pony of a player would be worthless because he plays great individual defense but doesn't have to score, rebound, or pass on the spurs and he would have to do those on a lesser team for that team to win. you put duncan on pretty much any team and he will dramatically improve that team (i'm guessing everyone would agree with that, no?), but if his +/- ratio is close to bruce bowen's what does that tell you?...

      my DOS simulation uses the +/- ratio and all you need do is run a few full season sims to see it doesn't tell you anything of significance. i can even manipulate a team's sub patterns to show how a single player can play on the same team for 82 games, but have a vastly different +/- ratio depending on who he plays with (i.e the first team or the 2nd team, the best of the team's player's or the worst of that team's players). so what does that tell you about +/- ratio?...

      bob chaikin
      bchaikin@...





    • Dean Oliver <deano@rawbw.com>
      ... conclusion ... you, what ... stating that ... easy...... Just to make sure -- I was just kidding about killing you off, Bob. I fully respect all your
      Message 2 of 29 , Jan 23, 2003
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        --- In APBR_analysis@yahoogroups.com, bchaikin@a... wrote:
        > Over at apbr_analysis, we've discussed the cross generational
        > comparison of players and teams and I think we reached the
        conclusion
        > that such comparisons are difficult or impossible to ground-truth.
        > There were some dissenters who we may just kill off.
        >
        > now why would you want to go and do that? if everyone agreed with
        you, what
        > fun would these discussion groups be?.....
        >
        > and who is "we"? i certainly don't agree with any conclusion
        stating that
        > directly comparing players over the past 40-45 years in the NBA is
        > "...difficult or impossible...". on the contrary, i find it fairly
        easy......

        Just to make sure -- I was just kidding about killing you off, Bob.
        I fully respect all your opinions. I just wouldn't trust any cross-
        generational simulation based on some of the reasons I mentioned
        before. And I would simply ask to prove that a cross-generational
        simulation works.

        DeanO
      • igorkupfer@rogers.com
        I hope the graphs came out okay. ... From: To: ; Sent: Thursday, January 23, 2003 2:00
        Message 3 of 29 , Jan 23, 2003
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          I hope the graphs came out okay.
           
          ----- Original Message -----
          From: <bchaikin@...>
          Sent: Thursday, January 23, 2003 2:00 PM
          Subject: [APBR_analysis] Cross Generational Simulating/Comparisons

          <snip>
          Bob:
          someone mentioned in previous postings a study by paleontologist stephen jay
          gould in his book "full house" (1996) where he talked about the disappearance
          of the .400 hitter in baseball as being due to a decrease in variation of
          batting averages (whose mean he states was stable over that same time) over
          the 130 years of baseball, and that that decrease in variation implys a
          general improvement of performance in the game of baseball over time, and
          that person posed the question of whether a .260 hitter in i think 1890 was
          the same as a .260 hitter today (gould would say no). since gould did a
          somewhat statistical study using standard deviations, and that was attempted
          by others here in this discussion group to try to find if an analogous
          situation in pro basketball existed using FG%s, lets look at what gould did,
          keeping in mind what we want to use his statistical evidence for - to ask can
          we compare directly basketball players of today to yesterday, are the players
          of today better than those of yesterday, and if so why, and can we simulate
          games between teams/players of today to yesterday, and if not where is any
          cutoff point...

          Ed:
          Gould was arguing for the reduction of variation among professional baseball players, by looking at batting averages. If we do the same for FG%, we can see that there is a small trend towards greater variation.
           
           
           
          Ed:
          The trend is clearer if we look at only the top 10 and bottom 10 from each season:
           
           

          <snip>
          Bob:

          ".....I do recognize that some improvement might be attributed to changing
          conditions, rather than absolutely improving play…older infields were
          apparently lumpier and bumpier thatn the productions of good ground crews
          today - so some of the poorer fielding of early days may have resulted from
          lousy fields rather than lousy fielders. I also recognize that rising
          averages must be tied in large part to great improvements in the design of
          gloves, but better equipment represents a major theme of history, and one of
          the legitimate reasons underlying my claim for general improvement in play…
          "(page 121)

          up and to this last quote i've given you an idea of what gould is saying, but
          re-read this last quote. basically what gould is saying is that, yes, i admit
          that while the rules of the game have remained essentially the same, that the
          conditions in the game have indeed changed (not to mentioned changes in
          stadiums, favoring either the hitters or pitchers as bill james stresses but
          gould ignores) over the years, but guess what - i don't care, they actually
          legitimize my point, i.e.. that doesn't change anything. he is saying that
          yes conditions of the game have changed, but he does not admit that that may
          be part of the reason, if not a major part, for players improving over the
          years....


          Ed:
          FWIW I agree that different generations can be meaningfully compared -- maybe even simulated. But Gould is talking about something different: the "improvement" he mentions takes place when the variation in true ability becomes smaller, dragging the mean level of play higher. We see a different pattern in basketball, where variation has at best remained constant, and maybe increased.
           
          It's important not to forget why this is relevant: the people who disagree with you by claimng that cross-generational comparisons are not very useful claim that the game is not the same as it once was. They can point to the greater variation in FG% as evidence showing that the players entering the league vary much more than  they did previously, and therefore the level of competition is not what it once was.
           
          Bob:
          this is very important for our discussion for basketball, where the
          conditions of the game haven't changed very much
           
          Ed:
          how does this effect your argument? If conditions haven't changed, then any differences we see across the years are due to the players themselves being different -- making comparisons more difficult, right?
           
          <snip>
           
          Bob:
          gould quotes james a number of times in his book, but its evident from
          reading these
          five chapters that he hasn't read james thoroughly. i think most would agree
          that bill james has probably done more for the understanding of baseball
          statistics over the years than has gould (and possibly more than anyone),
          especially when it comes to comparing players from different eras, and james
          has gone into detail about how the conditions of the game has changed
          (stadium size, lefty/righty, rule changes and outside influences) over the
          years...

          obviously gould hasn't read james most recent historical baseball abstract
          book (an update to his mid1980s book), kind of hard when six feet under, but
          the vast majority of the book is the same, so gould should have read all of
          james' mid-1980s edition.
           
          Ed:
          You are reading too much into what Gould was trying to say. His argument was only about the decreasing variation in true ability among baseball players -- I think he used fielding percentage as an example, too -- and how that could account for the disappearance of extreme hitting percentages. This is relevant to his argument about the diversity of life that follows the baseball chapters.

          <snip>
          Bob:
          so how does this relate to basketball? i contend that unless someone can show
          me how the game is different, condition wise, between the years of the mid to
          late 1950s to today, as james has done for basketball, that like gould we can
          look at the numbers directly. gould only looked at the numbers and james has
          shown that this needs refinement based on how the comditions of the game have
          changed. i would love to see some arguments on how conditions in basketball
          have changed from the mid-to-late 1950s to today, thus having the stats
          affected in some way, such that the numbers cannot be compared directly, but
          i have yet to see this...
           
          Ed:
          Well, I won't be the one to claim that conditions are so different that comparisons become meaningless. I am completely agnostic on that issue. However, I do wish to preserve Gould's argument in it's proper context: he only tried to show that variation had decreased over time. That's it, he had nothing to say about differing conditons because they were irrelevant to his argument.

          <snip>
           
          Bob:
          ".....Wade boggs would hit .400 every year against the pitching and fielding
          of the 1890s, while wee willie keeler would be lucky to crack .320 today...."
          (page 125)

          this is a preposterous statement. what would wade boggs have done when he got
          sick, or just a cold, back then? how about a pulled muscle? a broken finger?
          Ed:
          Because, of course, no modern athlete has ever tried to play through an injury.
           
          Gould's point, in context, was that the very greatest hitters of today stand as close to the extreme limits of human ability as those of yesteryear -- and that hitting percentage was not a measure of true ability, but only relative ability against the opposing pitcher. In basketball he would've said that Shaquille O'Neal's best seasons stand next to Wilt's, even though the raw numbers are different.
           
          <snip>
          Bob:
          until a study is done similar to what gould did, showing the standard
          deviation of not just FG% but a multitude of other stats have had
          convincingly shrinking variation thru time from the mid to late 1950s to
          today in pro hoops i certainly do not see any evidence that the game has
          changed to the point that the players cannot be compared directly based on
          their stats...
          FT% is the only unambiguous indicator of at least one ability, since the question of defense is removed.
           
           
           
          Ed:
          We see the same pattern: increasing variation in league-wide talent levels, opposite of what Gould tried to show in baseball.

          Bob:
          "....Symmetrically shrinking variation in batting averages must record
          general improvement of play for two reasons - the first because systems
          manned by the best performers in competition, and working under the same
          rules through time, slowly discover optimal procedures and reduce their
          variation as all personnel learn and master the best ways: the second because
          the mean moves toward the right wall, thus leaving less space for the spread
          of variation…as variation shrinks because general play improves, .400 hitting
          disappears as a consequence of increasing excellenece in play...." (page 128)

          this is gould's conclusion. but how does it stand up to the test of time with
          barry bonds recent slugging percentage marks, and the complete repeated
          wipeout of babe ruth and roger maris's home run records by mcgwire, sosa, and
          bonds? as james would say, its the conditions of the game that are different,
          not the players...
          Ed:
          I agree that Gould soft-pedals this point. But I hardly see how your argument is strengthened -- after all, if players are bigger, stronger, faster than before, wouldn't this make comparisons more difficult?
           
          <snip>
           
          ed
        • bchaikin@aol.com
          Just to make sure -- I was just kidding about killing you off, Bob. I fully respect all your opinions. I just wouldn t trust any cross- generational
          Message 4 of 29 , Jan 23, 2003
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            Just to make sure -- I was just kidding about killing you off, Bob. 
            I fully respect all your opinions.  I just wouldn't trust any cross-
            generational simulation based on some of the reasons I mentioned
            before.  And I would simply ask to prove that a cross-generational
            simulation works.

            a threat is a threat - and i am prepared. should you ever dare to come thru my front door, my 14 year old cat will, beveled fangs, declawed, and all, in between bringing up frequent furballs and his mental lapses (where's that damn food bowl), will lick you to death - take the skin right off the bone (give or take a few weeks)......

            you have been warned...

            I just wouldn't trust any cross-generational simulation based on some of the reasons I mentioned before.  And I would simply ask to prove that a cross-generational
            simulation works.

            well i guess some people have to be dragged kicking and screaming into the 21st century - so what would constitute proof, or more specifically, what would constitute proof to you? if i can simulate individual select seasons and reproduce accurate results (team W-L records, individual player stats) is that or is that not proof the sim works over the course of one season? if i can then replace, say, a 2000-01 team with a 2001-02 team with an identical real life W-L record (say replace the bulls of 00-01 with the bulls of 01-02), and then play that 2001-02 team in a league with 2000-01 teams and get a similar or identical W-L record, is that enough proof? if i then run that 2001-02 team in a league with the 1999-2000 teams, and get a similar if not identical record, is that enough proof? then a 2001-02 team in a league with 1998-99 teams, get a similar result, is that enough proof? and so on down the line...

            i can do this, and place those results right in front of you (at least for the late 1970s to today, more accurately the 97-98 season), but you can still claim that's not proof. if your answer is that since it can't be done in real life thus there is no way to prove it, then why this discussion?...

            i've been asking for proof or statistical evidence (or any evidence) that the eras are not directly comparable. the gould study was a good start - a statistical study to try to show something. i understand what he was trying to do but do not think he went far enough (at least for the purposes of our discussion here), although his results are promising (showing a difference from the late 1800s to late 1900s, but not the 1940s to 1980). i did not bring up his study, someone else did - i simply tried to evaluate what he did in terms of how it could help our discussion, since a similar study for hoops has not been done (at least that i know of)...

            bob chaikin
            bchaikin@...












          • bchaikin@aol.com
            Gould was arguing for the reduction of variation among professional baseball players, by looking at batting averages. If we do the same for FG%, we can see
            Message 5 of 29 , Jan 23, 2003
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              Gould was arguing for the reduction of variation among professional baseball players, by looking at batting averages. If we do the same for FG%, we can see that there is a small trend towards greater variation.

              i have not seen this small trend towards greater variation, but if that is the case, then are we saying that the increase in variability is a sign that overall play has diminished in some way? i don't know if i agree with that - i'd have to look at a number of other stats other than just FG%, as gould did not look at any other stats other than batting average...

              I agree that different generations can be meaningfully compared -- maybe even simulated. But Gould is talking about something different: the "improvement" he mentions takes place when the variation in true ability becomes smaller, dragging the mean level of play higher. We see a different pattern in basketball, where variation has at best remained constant, and maybe increased.

              i fully understand what gould is trying to show. i too am a geologist, and quite familiar with paleontological studies, including cladistics. but using stats for predator-to-prey ratios (such as bakker did to show his evidence for dinosaur warm-bloodedness) and converting that to baseball i'm not sure about yet. but assuming for the moment he is correct, he'd have to look at a number of other stats and take into consideration other factors to prove his point to me. yes i can see his point that variation in a process decreases as the process
              is streamlined so to speak, but does that automatically mean an overall increase in the "effectiveness" of the process? that is a discussion for another group i believe...

              It's important not to forget why this is relevant: the people who disagree with you by claimng that cross-generational comparisons are not very useful claim that the game is not the same as it once was. They can point to the greater variation in FG% as evidence showing that the players entering the league vary much more than  they did previously, and therefore the level of competition is not what it once was.

              if the level on competition is not now what it once was (sometime earlier), does that not insinuate poorer overall play now? not sure of the point you are making. gould has shown (suppossedly) that baseball is not the same in the late 1800s as it is in 1980, i.e. it was better in 1980, beter overall play. but he did not show that for the eras of 1940 to 1980, and we are looking at basketball from the mid-1950s to today, a similar time period, when athletes had to endure similar non-playing conditions (travel, medical treatment, etc)...

              Bob:
              this is very important for our discussion for basketball, where the
              conditions of the game haven't changed very much

              Ed:
              how does this effect your argument? If conditions haven't changed, then any differences we see across the years are due to the players themselves being different -- making comparisons more difficult, right

              on the contrary. bill james shows (contends) that because of influences other than the actual game on the field, stats changed. larger stadiums and other factors (rules changes, etc) were more responsible for a dominance in pitching in the 1950s to 1960s, other factors for the 1990s (to favor hitting). but he states that hitters were not better in the 1990s than in the 1960s, but he states that the conditions of the game had changed. we don't have this problem in pro basketball, as far as i can tell, i.e. there were no changes to the court itself for instance. if for example the court was lengthened by 10-20 feet for a couple of years you might see a difference in stats that we can relate to that occurring. but we don't. the closest thing we have was the bringing in of the 3pt line showing more 3pters taken, but that had little affect on the game overall, as did the first bringing in the 3pters in 79-80. if we raised or lowered the rim by 6 inches for a season, we might see changes in stats that we could directly relate to that change, but the changes in stats over the past 45+ years cannot be accorded to any physical change to the game itself - again as far as i can tell. if anyone thinks otherwise, please inform me...

              You are reading too much into what Gould was trying to say. His argument was only about the decreasing variation in true ability among baseball players -- I think he used fielding percentage as an example, too -- and how that could account for the disappearance of extreme hitting percentages. This is relevant to his argument about the diversity of life that follows the baseball chapters.

              no i fully understand what gould is saying. my point is that someone else used gould's study to make a point, and i tried to show that his study actually helps to verify my point of view - i.e. he shows little change in baseball from the 1940s to today in terms of the variability of batting average, the same time period (or close) to the time period for basketball we are discussing. also his study needs to consider more stats and not just batting average to make his point...

              Well, I won't be the one to claim that conditions are so different that comparisons become meaningless. I am completely agnostic on that issue. However, I do wish to preserve Gould's argument in it's proper context: he only tried to show that variation had decreased over time. That's it, he had nothing to say about differing conditons because they were irrelevant to his argument.

              to be more exact he was trying to show that "...a variation decrease in time means an overall increase in general play...". the fact that he does not take into account conditions in the game that james has shown altered the statistical results in predictable way means gould did not go far enough to prove his point...

              Bob:
              ".....Wade boggs would hit .400 every year against the pitching and fielding
              of the 1890s, while wee willie keeler would be lucky to crack .320 today...."
              (page 125)

              this is a preposterous statement. what would wade boggs have done when he got
              sick, or just a cold, back then? how about a pulled muscle? a broken finger?

              Ed:
              Because, of course, no modern athlete has ever tried to play through an injury.

              what is your point? that conditions of the game of baseball were the same back then as today? if so explain why because i fully disagree...

              Gould's point, in context, was that the very greatest hitters of today stand as close to the extreme limits of human ability as those of yesteryear -- and that hitting percentage was not a measure of true ability, but only relative ability against the opposing pitcher.

              that's gould's general point, but not the point he makes in this example. gould here is blatantly saying that a great player (high average hitter) today would be better, if not much better, than the best great players (high average hitters i should say) of keeler's time. no player back then hit .400 every year (keeler did once from 1894-1900), and to insinuate that boggs would if placed back in that time fully ignores the conditions of the game as they were back then, as gould has ignored throughout his study. for christ sakes they weren't cavemen back in the late 1800s - they were athletes, the best baseball players of their times, and the best ones got paid very well for their time....

              keeler was the best hitter in baseball from 1894-1900, batting .383 during that time, a time when the league averaged .289. burkett and delahanty were not far behind, and as far as average goes those three were the best (others were over 10 points less). boggs best 7 years were from 1982-1988, when he hit .356, and the league averaged .259. both were just under 100 points over the league average for their time. for all that gould said about boggs, i could easily say that if you put keeler into today's game, let him train on weights every day, have 2-3 hitting coaches (as in spring training, saunas, hot tubs, great nutrition, medical treatment, like boggs did, maybe he would have hit .400 every season. now does that make any sense to you? it doesn't to me, but its a similar arguement...

              remember gould talked about athletes hitting that proverbial right wall, and then bonds goes and tears up the league like noone has ever done and not one but several players blow away the ruth/maris HR record. what does that say for gould's study?...

              until a study is done similar to what gould did, showing the standard deviation of not just FG% but a multitude of other stats have had convincingly shrinking variation thru time from the mid to late 1950s to today in pro hoops i certainly do not see any evidence that the game has changed to the point that the players cannot be compared directly based on their stats...

              FT% is the only unambiguous indicator of at least one ability, since the question of defense is removed.

              and that one statistical parameter that is unambiguous hasn't changed over the past 45+ years, has it?...

              In basketball he would've said that Shaquille O'Neal's best seasons stand next to Wilt's, even though the raw numbers are different..

              no he is blatantly saying boggs would be much better than keeler...

              in my humble opinion i don't think there's any question that o'neal could score more if the team wanted him to, upwards of 35 maybe 40 pts/g (jordan scored 37 pts/g in 86-87 and the bulls won only 40 games, and he was a guard)? this was the problem with chamberlain. he admitted in writing that the team owner wanted him to score as much as possible to draw fans...

              consider hockey - gretzky came along and blew away every record conceivable in the NHL in the early 1980s, and his teams won big. does this mean the game was not being streamlined (overall increase in general play) as gould says baseball was at that time of say the 60 years prior to gretzky's arrival. this is similar to what bonds did in baseball, yet gould is saying that it shouldn't happen as the process of the game is "leveling out"....

              I agree that Gould soft-pedals this point. But I hardly see how your argument is strengthened -- after all, if players are bigger, stronger, faster than before, wouldn't this make comparisons more difficult?

              gould shows that batting averages haven't changed at all (no variation in the standard deviation) from the 1940s to 1980 (but did from 1875 to 1980). i'm saying similarily that there is no discernable variation in the stats from the mid to late 1950s to today for basketball stats - about the same time period of 1940-1980 where gould finds no change) where athletes of both sports had similar off-the-field-conditions for weight training (or lack of it), nutrition, travel, etc. the one person in this discussion group that looked at the standard deviation of FG% also did not find any discernable pattern to say one way or the other if in-game conditions had changed. bill james contends the game of baseball is pretty much the same in the 1960s compared to the 1990s, when most would look at the numbers and say otherwise. i'm saying the same for basketball, and that you can thus simulate directly the eras...

              bob chaikin
              bchaikin@...
























            • Dean Oliver <deano@rawbw.com>
              ... some of the ... into the ... specifically, what ... seasons ... stats) is ... season? if i ... identical ... of ... teams and ... then run ... similar if
              Message 6 of 29 , Jan 25, 2003
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                --- In APBR_analysis@yahoogroups.com, bchaikin@a... wrote:
                > I just wouldn't trust any cross-generational simulation based on
                some of the
                > reasons I mentioned before. And I would simply ask to prove that a
                > cross-generational
                > simulation works.
                >
                > well i guess some people have to be dragged kicking and screaming
                into the
                > 21st century - so what would constitute proof, or more
                specifically, what
                > would constitute proof to you? if i can simulate individual select
                seasons
                > and reproduce accurate results (team W-L records, individual player
                stats) is
                > that or is that not proof the sim works over the course of one
                season? if i
                > can then replace, say, a 2000-01 team with a 2001-02 team with an
                identical
                > real life W-L record (say replace the bulls of 00-01 with the bulls
                of
                > 01-02), and then play that 2001-02 team in a league with 2000-01
                teams and
                > get a similar or identical W-L record, is that enough proof? if i
                then run
                > that 2001-02 team in a league with the 1999-2000 teams, and get a
                similar if
                > not identical record, is that enough proof? then a 2001-02 team in
                a league
                > with 1998-99 teams, get a similar result, is that enough proof? and
                so on
                > down the line...
                >

                For fear of further inciting Bob's cat into killer lick mode --- No,
                your test isn't enough proof. The concept that simulating one team
                from one year against the league from the year before should produce
                similar records for the two is definitely palatable. But I think it
                doesn't answer the question of whether the record should be better or
                worse. The contention by some is that a team playing a league from
                the year before should generally be better (leagues get better with
                time). Your simulation provides no way of saying whether that is
                right or wrong. I'm not saying that the simulation is wrong. It
                just provides no insight on the fundamental question -- are leagues
                getting better or staying the same or getting worse? The simulation
                _could_ be right, but I think some of the statements spelled out by
                Steve aren't really addressed by your simulation. The premise that
                records should be similar when playing one team from this year
                against the league of the previous year makes some sense but assumes
                away what we are trying to know.

                Let the cat loose!

                DeanO
              • John Hollinger <alleyoop2@yahoo.com>
                bill james contends the game of baseball is pretty much the same in the 1960s compared to the 1990s, when most would look at the numbers and say otherwise.
                Message 7 of 29 , Jan 25, 2003
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                  "bill james contends the game of baseball is pretty much the same in
                  the 1960s compared to the 1990s, when most would look at the numbers
                  and say otherwise. i'm saying the same for basketball, and that you
                  can thus simulate directly the eras..."

                  If you're saying that it should be possible to compare players from
                  different eras, once some kind of adjustment is made for the
                  differences, then I agree with you.

                  If you're saying the players from the 1950s and 1960s are JUST AS
                  GOOD as they players today, I couldn't disagree with you more
                  emphatically.

                  Even after adjusting for the weight training, travel, improvements in
                  medicine, etc., there is one huge, clear difference between baseball
                  in the 1950s and 1960s and basketball in the 1950s and 1960s:

                  Baseball, as North America's most popular sport, was already drawing
                  in almost all of the people in the population who were genuinely
                  talented. But there was never the same pull to get the best athletes
                  into basketball, because its popularity has only bloomed in the last
                  30 years.

                  Basketball, on the other hand, was not. In fact, absurdly, obviously
                  not. George Mikan was a giant at the time,l but he was 6-10, 245.
                  Slater Martin was 5-10. Jim Pollard was 6-5, 185 and often played
                  power forward.

                  Those were the cornerstones of the BEST team of the 1950s; you can't
                  seriously tell me that, even with modern weight training and diet,
                  those guys could walk out on the floor and hang with the Kings for
                  four quarters.
                • bchaikin@aol.com
                  If you re saying that it should be possible to compare players from different eras, once some kind of adjustment is made for the differences, then I agree with
                  Message 8 of 29 , Jan 25, 2003
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                    If you're saying that it should be possible to compare players from different eras, once some kind of adjustment is made for the differences, then I agree with you.

                    adjustment? like what kind of adjustment? "...made for the differences..." what differences? again - here is someone saying, emphatically, that some kind of adjustment is needed (i'm assuming to the stats), and that there are some kind of differences, but does not state what they are, for whatever reason, nor does he give any manor of clue or clues as to what he means.....once again statements made not backed up by any kind of evidence or fact...

                    If you're saying the players from the 1950s and 1960s are JUST AS GOOD as they players today, I couldn't disagree with you more emphatically.

                    you can disagree all you want, but as this is a stats analysis group, lets hear your reasons why...

                    Even after adjusting for the weight training, travel, improvements in medicine, etc., there is one huge, clear difference between baseball in the 1950s and 1960s and basketball in the 1950s and 1960s:

                    all right, my eyes and ears are wide open now.....to hear this "...one huge, clear difference..."...

                    Baseball, as North America's most popular sport, was already drawing in almost all of the people in the population who were genuinely talented. But there was never the same pull to get the best athletes into basketball, because its popularity has only bloomed in the last 30 years. Basketball, on the other hand, was not. In fact, absurdly, obviously not.

                    oh, really?......absurdly, obviously not?.........fine - then lets look at this closely......

                    this is 2003, thirty years ago would be 1973. are you trying to tell me that prior to 1973 (the 1950s and 1960s), the best basketball athletes or basketball players in the country might not have been playing basketball, not pursuing pro basketball as a career? that pro basketball was not "....drawing in almost all of the people in the population who were genuinely talented..." like pro baseball was?....

                    let me get this straight - are you saying that people who were very good at basketball, say, at a college level back then some 30+ odd years ago, were pursuing careers other than pro basketball who could have been in the pros? is this what you are saying? that this god awfully good basketball talent was doing something other than playing pro basketball? or are you saying that there weren't enough good players around to make the NBA competitive?...

                    you're joking right?...

                    fyi - not just 30 years ago but 35-40 and more years ago there was so much talent in terms of pro basketball players in this country, great players could not make it into the pros because they weren't good enough (meaning the players in the NBA were the very best the country had to offer) because the league had only 8 teams,  and because of that great extra talent that not only was the NBA expanding from 8 to 9 teams, then 9 to 10 teams, then 10 to 12 teams, and then 12 to 14 teams in the span of less than a decade (in the 1960s), but a second pro league was started up in 1967-68 with another 11 teams (you may have heard of it - it was called the ABA)....

                    so in 65-66 there were 9 pro teams and 3 years later, by 1968-69, there were, what, 25 total pro teams between the NBA and ABA?...

                    Basketball, on the other hand, was not. In fact, absurdly, obviously not.


                    absurdly, obviously, not? uh...yep...i can see your point......pro hoops wasn't too popular back then...

                    (if in your eyes there were college players that were blatantly good enough in college to be NBA pro players and possibly dominate the NBA but did not, prior to the league expanding to more than 8 teams, that went on to become accountants or lawyers or whatever rather than play pro hoops, lets hear who you think they were)...

                    George Mikan was a giant at the time,l but he was 6-10, 245. Slater Martin was 5-10. Jim Pollard was 6-5, 185 and often played power forward.

                    again, what is your point here? what does height have to do with it? charles barkley was 6'5" and he was a power forward, no? he was pretty good, no? muggsy bogues, spud webb, earl boykins were all smaller than martin, they were pretty good, no? dennis rodman was 6'8" in a land of a multitude 7 footers, and he dominated the boards for some time. you ever heard of a player named leonard "truck" robinson? he was 6'7" and 230 lbs and lead the league in rebounding (new orleans jazz) in the late 1970s...

                    in 1968-69 (34 years ago), when the NBA was dominated by such big men as 7'1" wilt chamberlain, 6'9" bill russell, 6'11" elvin hayes, 6'9" bob rule, 6'11' nate thurmond, 6'10" walt bellamy, 6'9" zelmo beaty, 6'8" jerry lucas, most of these mentioned are hall of famers, and many others, and long before - i guess - basketball was popular enough to bring in top rated talent (your words - cause they were looking for other jobs i guess), a scrawny little 6'7" rookie by the name of wes unseld came into the league and dominated in such a way that he not only captured the league's rookie of the year award but also the league's most valuable player award (can't remember if that ever happened again)??...

                    so here was a league - so denuded of talent (i guess) - because its popularity hadn't "...bloomed yet..." so as to pull in the best talent available from around the country, not only expands its number of teams (almost doubling the number of teams in less than a decade) but supposedly dilutes its talent base because it was bringing in so many new players and teams in such a short period of time, and a player 3 inches shorter than big old lumbering george mikan dominates the league filled with the above mentioned super talent in such a way and to such a degree that he is named both ROY and MVP?? and you're trying to tell me the league wasn't bringing the best talent from around the country? who you trying to kid?...

                    are you telling me that a 6'7" rookie named wes unseld, who faced chamberlain and russell and hayes and thurmond (all hall of famers) twice as often as if he was a rookie of today would face o'neal and shawn bradley and yao ming and whomever else (because there are now twice as many teams as back then) would not be just as good in today's game? someone who beat down the doors of a number of hall of famers?....

                    Those were the cornerstones of the BEST team of the 1950s; you can't seriously tell me that, even with modern weight training and diet, those guys could walk out on the floor and hang with the Kings for four quarters.

                    i couldn't be more serious.......i don't think there is any question that the players of the 30+ years ago could play equally competitively against the players of today, and even the players of the mid-to-late 1950s (as i've stated all along with this cross generational debate - not early 1950s), especially if they had access to what the players of today have - they were of equal talent in my opinion.....

                    is that "...in fact, absurdly obvious..."?...

                    bob chaikin
                    bchaikin@...











                  • John Hollinger <alleyoop2@yahoo.com>
                    You re right: I can t empirically prove it. This is the problem with this debate, and I don t know how to solve it. So, while there s no way for me to
                    Message 9 of 29 , Jan 26, 2003
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                      You're right: I can't empirically prove it. This is the problem with
                      this debate, and I don't know how to solve it.

                      So, while there's no way for me to empirically show that a kid who
                      was six-foot-three in the eighth grade had a far less chance of being
                      pushed into basketball rather than football, boxing or baseball 30-40
                      years ago than he did today, I think the increase in average player
                      size is a pretty good indication that it has happened. If it were
                      just because of better diet/weight training, it would mimic the
                      changes in say, baseball, but that hasn't happened.

                      There are more subtle indications. Position evolution is a good one.
                      There are multiple players from the 1970s, for instance, who began
                      their careers as power forwards and ended them as shooting guards,
                      Julius Erving and Jamaal Wilkes being the most obvious. The reason,
                      obviously, is that everyone grew around them to the point that they
                      couldn't compete as power forwards anymore; but they were good
                      enought to develop other skills (jumper, ballhandling) and evolve so
                      they could still be productive players.

                      I used the guys from the 50s because their the most obvious,
                      ridiculous example. I can't definitively tell you that Dave
                      DeBusschere couldn't get by at power forward at 6-6, 230 if he played
                      today; I don't think he could, but it's not as strong an argument as
                      Joe Fulks, who obviously couldn't split time between power forward
                      and center at 6-5, 190 if he played today, or Ed Macauley (6-8, 190).

                      Asking how to prove it is a fair question, and as we've already
                      discussed a damn hard one. But I have no doubt whatsoever that many,
                      many players from 30, 40 and 50 years ago would either need to play a
                      different position or would play their own spot less effectively.




                      --- In APBR_analysis@yahoogroups.com, bchaikin@a... wrote:
                      > If you're saying that it should be possible to compare players from
                      different
                      > eras, once some kind of adjustment is made for the differences,
                      then I agree
                      > with you.
                      >
                      > adjustment? like what kind of adjustment? "...made for the
                      differences..."
                      > what differences? again - here is someone saying, emphatically,
                      that some
                      > kind of adjustment is needed (i'm assuming to the stats), and that
                      there are
                      > some kind of differences, but does not state what they are, for
                      whatever
                      > reason, nor does he give any manor of clue or clues as to what he
                      > means.....once again statements made not backed up by any kind of
                      evidence or
                      > fact...
                      >
                      > If you're saying the players from the 1950s and 1960s are JUST AS
                      GOOD as
                      > they players today, I couldn't disagree with you more emphatically.
                      >
                      > you can disagree all you want, but as this is a stats analysis
                      group, lets
                      > hear your reasons why...
                      >
                      > Even after adjusting for the weight training, travel, improvements
                      in
                      > medicine, etc., there is one huge, clear difference between
                      baseball in the
                      > 1950s and 1960s and basketball in the 1950s and 1960s:
                      >
                      > all right, my eyes and ears are wide open now.....to hear
                      this "...one huge,
                      > clear difference..."...
                      >
                      > Baseball, as North America's most popular sport, was already
                      drawing in
                      > almost all of the people in the population who were genuinely
                      talented. But
                      > there was never the same pull to get the best athletes into
                      basketball,
                      > because its popularity has only bloomed in the last 30 years.
                      Basketball, on
                      > the other hand, was not. In fact, absurdly, obviously not.
                      >
                      > oh, really?......absurdly, obviously not?.........fine - then lets
                      look at
                      > this closely......
                      >
                      > this is 2003, thirty years ago would be 1973. are you trying to
                      tell me that
                      > prior to 1973 (the 1950s and 1960s), the best basketball athletes
                      or
                      > basketball players in the country might not have been playing
                      basketball, not
                      > pursuing pro basketball as a career? that pro basketball was
                      not "....drawing
                      > in almost all of the people in the population who were genuinely
                      talented..."
                      > like pro baseball was?....
                      >
                      > let me get this straight - are you saying that people who were very
                      good at
                      > basketball, say, at a college level back then some 30+ odd years
                      ago, were
                      > pursuing careers other than pro basketball who could have been in
                      the pros?
                      > is this what you are saying? that this god awfully good basketball
                      talent was
                      > doing something other than playing pro basketball? or are you
                      saying that
                      > there weren't enough good players around to make the NBA
                      competitive?...
                      >
                      > you're joking right?...
                      >
                      > fyi - not just 30 years ago but 35-40 and more years ago there was
                      so much
                      > talent in terms of pro basketball players in this country, great
                      players
                      > could not make it into the pros because they weren't good enough
                      (meaning the
                      > players in the NBA were the very best the country had to offer)
                      because the
                      > league had only 8 teams, and because of that great extra talent
                      that not
                      > only was the NBA expanding from 8 to 9 teams, then 9 to 10 teams,
                      then 10 to
                      > 12 teams, and then 12 to 14 teams in the span of less than a decade
                      (in the
                      > 1960s), but a second pro league was started up in 1967-68 with
                      another 11
                      > teams (you may have heard of it - it was called the ABA)....
                      >
                      > so in 65-66 there were 9 pro teams and 3 years later, by 1968-69,
                      there were,
                      > what, 25 total pro teams between the NBA and ABA?...
                      >
                      > Basketball, on the other hand, was not. In fact, absurdly,
                      obviously not.
                      >
                      > absurdly, obviously, not? uh...yep...i can see your point......pro
                      hoops
                      > wasn't too popular back then...
                      >
                      > (if in your eyes there were college players that were blatantly
                      good enough
                      > in college to be NBA pro players and possibly dominate the NBA but
                      did not,
                      > prior to the league expanding to more than 8 teams, that went on to
                      become
                      > accountants or lawyers or whatever rather than play pro hoops, lets
                      hear who
                      > you think they were)...
                      >
                      > George Mikan was a giant at the time,l but he was 6-10, 245. Slater
                      Martin
                      > was 5-10. Jim Pollard was 6-5, 185 and often played power forward.
                      >
                      > again, what is your point here? what does height have to do with
                      it? charles
                      > barkley was 6'5" and he was a power forward, no? he was pretty
                      good, no?
                      > muggsy bogues, spud webb, earl boykins were all smaller than
                      martin, they
                      > were pretty good, no? dennis rodman was 6'8" in a land of a
                      multitude 7
                      > footers, and he dominated the boards for some time. you ever heard
                      of a
                      > player named leonard "truck" robinson? he was 6'7" and 230 lbs and
                      lead the
                      > league in rebounding (new orleans jazz) in the late 1970s...
                      >
                      > in 1968-69 (34 years ago), when the NBA was dominated by such big
                      men as 7'1"
                      > wilt chamberlain, 6'9" bill russell, 6'11" elvin hayes, 6'9" bob
                      rule, 6'11'
                      > nate thurmond, 6'10" walt bellamy, 6'9" zelmo beaty, 6'8" jerry
                      lucas, most
                      > of these mentioned are hall of famers, and many others, and long
                      before - i
                      > guess - basketball was popular enough to bring in top rated talent
                      (your
                      > words - cause they were looking for other jobs i guess), a scrawny
                      little
                      > 6'7" rookie by the name of wes unseld came into the league and
                      dominated in
                      > such a way that he not only captured the league's rookie of the
                      year award
                      > but also the league's most valuable player award (can't remember if
                      that ever
                      > happened again)??...
                      >
                      > so here was a league - so denuded of talent (i guess) - because its
                      > popularity hadn't "...bloomed yet..." so as to pull in the best
                      talent
                      > available from around the country, not only expands its number of
                      teams
                      > (almost doubling the number of teams in less than a decade) but
                      supposedly
                      > dilutes its talent base because it was bringing in so many new
                      players and
                      > teams in such a short period of time, and a player 3 inches shorter
                      than big
                      > old lumbering george mikan dominates the league filled with the
                      above
                      > mentioned super talent in such a way and to such a degree that he
                      is named
                      > both ROY and MVP?? and you're trying to tell me the league wasn't
                      bringing
                      > the best talent from around the country? who you trying to kid?...
                      >
                      > are you telling me that a 6'7" rookie named wes unseld, who faced
                      chamberlain
                      > and russell and hayes and thurmond (all hall of famers) twice as
                      often as if
                      > he was a rookie of today would face o'neal and shawn bradley and
                      yao ming and
                      > whomever else (because there are now twice as many teams as back
                      then) would
                      > not be just as good in today's game? someone who beat down the
                      doors of a
                      > number of hall of famers?....
                      >
                      > Those were the cornerstones of the BEST team of the 1950s; you
                      can't
                      > seriously tell me that, even with modern weight training and diet,
                      those guys
                      > could walk out on the floor and hang with the Kings for four
                      quarters.
                      >
                      > i couldn'be more serious.......i don't think there is any question
                      that the
                      > players of the 30+ years ago could play equally competitively
                      against the
                      > players of today, and even the players of the mid-to-late 1950s (as
                      i've
                      > stated all along with this cross generational debate - not early
                      1950s),
                      > especially if they had access to what the players of today have -
                      they were
                      > of equal talent in my opinion.....
                      >
                      > is that "...in fact, absurdly obvious..."?...
                      >
                      > bob chaikin
                      > bchaikin@b...t
                    • schtevie2003 <schtevie@hotmail.com>
                      Hello again all. It appears that the dead equine will receive another whuppin .....sorry. Comments by Bob Chaikin: i certainly don t agree with any conclusion
                      Message 10 of 29 , Jan 27, 2003
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                        Hello again all. It appears that the dead equine will receive
                        another whuppin'.....sorry.

                        Comments by Bob Chaikin:

                        i certainly don't agree with any conclusion stating that
                        > directly comparing players over the past 40-45 years in the
                        NBA is
                        > "...difficult or impossible...". on the contrary, i find it fairly
                        easy......

                        > i've read every single post on both discussions groups since
                        this discussion
                        > on "...are the players of today better than the players of
                        yesterday..." and,
                        > more exactly, "...how could we simulate cross-generational pro
                        basketball..."
                        > began a number of weeks ago, patiently waiting for any kind of
                        proof or
                        > evidence in terms of some discussion stating why players
                        cannot be compared
                        > directly over the past decades, and while i have heard a
                        number of people
                        > state it can't, or shouldn't be done, i haven't seen any definitive
                        reasons
                        > why. i remain wholely unconvinced by the arguements
                        presented so far, and
                        > would love to debate any discussion that actually trys to
                        explains why it
                        > can't be done accurately using the actual stats...

                        ***********

                        My argument as to why cross-generational simulations using
                        actual stats are certain to yield irrelevant results (if borne out)
                        has to do with the fact that over a 20 year period (again
                        apologies for the imprecision in dating) roughly the 1960s and
                        60s there was a dramatic improvement in the way the game was
                        played. To retell the punchline before the set-up: the superiority
                        of the average team in the early 80 to its 60s counterpart was on
                        the order of 10 to 12 points per game (at a modern game pace).
                        This is equivalent to how much better the best Bulls team was to
                        the league average.

                        Now, how do I know this to be true (until someone disabuses
                        me of the notion)? Just looking at the average offensive
                        productivity over the time in question, what one sees is that it
                        improved dramatically (the 12 points per game above). Now,
                        those who believe we stand on the shoulders of giants might be
                        inclined to say that defenses got worse as opposed to offenses
                        having improved. Is this view tenable? The answer is "no"
                        because the trend is accompanied by a dramatic slowing of the
                        game. This slowing, all else equal, implies that offensive
                        productivity should have decreased. Why? It either means
                        fast-break baskets were being reduced or that the half-court
                        offenses were having to work harder for shots. But offenses
                        improved, dramatically. And the only explanation I can deduce is
                        that offenses were disciplining themselves (through improved
                        coaching I surmise) and expunging bad shot selection. Now, as
                        I also said before, I expect that defenses were also improving
                        during this time so that the 12 point estimate is in fact a low
                        estimate of the actual improvement in these two decades.

                        And to continue. If one accepts the general and continuous
                        improvement of the game over the two decades mentioned, then
                        it becomes arbitrary to imagine that progress stopped then. The
                        reasonable prior belief is that the slow decrease in offensive
                        productivity after this point is the result of defensive
                        improvements, rather than some technological retrogression.

                        And finally, I made what I think is a very persuasive argument for
                        the superiority of the trained athlete in more recent times. In the
                        form of a question, if there are not some return to his efforts, why
                        is he killing himself in the gym?

                        There is the "proof". I look forward to any alternate explanation of
                        these facts and inferences.

                        All this aside, I should say that I have nothing but the highest
                        regard for the notion of using simulations for analyzing the game
                        of basketball. To my mind, they are the best method for
                        understanding the effect of marginal changes in game variables.

                        However, they are not useful - only highly deceptive - in
                        determining the competitiveness of NBA teams from different
                        eras.
                      • bchaikin@aol.com
                        the superiority of the average team in the early 80 to its 60s counterpart was on the order of 10 to 12 points per game (at a modern game pace). This is
                        Message 11 of 29 , Jan 27, 2003
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                          the superiority of the average team in the early 80 to its 60s counterpart was on
                          the order of 10 to 12 points per game (at a modern game pace).  This is equivalent to how much better the best Bulls team was to the league average.

                          not sure what these numbers mean or where they are coming from....how did you arrive at this or derive these numbers?...

                          Just looking at the average offensive productivity over the time in question, what one sees is that it improved dramatically (the 12 points per game above).

                          would love to "look" at it but you're not showing anything...

                          Now, those who believe we stand on the shoulders of giants might be inclined to say that defenses got worse as opposed to offenses having improved.  Is this view tenable?  The answer is "no" because the trend is accompanied by a dramatic slowing of the game.  This slowing, all else equal, implies that offensive productivity should have decreased. .  Why?  It either means fast-break baskets were being reduced or that the half-court offenses were having to work harder for shots.  But offenses improved, dramatically...

                          here are some number for you to chew on:

                                                   pts/      sec/      pts/
                          year        FG%   48min   poss     poss
                          7778      .469     107.7    13.4      1.000
                          7879      .485     109.8    13.5      1.029
                          7980      .481     108.5    13.8      1.041   
                          8081      .486     107.5    14.0      1.043
                          8182      .491     107.9    14.1      1.058
                          8283      .485     107.9    13.8      1.037
                          8384      .492     109.2    14.0      1.063
                          8485      .491     110.2    13.9      1.066
                          8586      .487     109.5    13.9      1.059
                          8687      .480     109.2    14.1      1.067
                          8788      .480     107.6    14.3      1.065
                          8889      .477     108.5    14.1      1.062
                          8990      .476     106.3    14.4      1.065
                          9091      .474     105.5    14.5      1.063
                          9192      .472     104.5    14.7      1.067
                          9293      .473     104.5    14.7      1.066
                          9394      .466     101.0    15.0      1.049
                          9495      .466     100.6    15.3      1.069
                          9596      .462      98.8     15.5      1.063
                          9697      .455      96.2     15.8      1.053
                          9798      .450      94.8     15.7      1.036
                          9899      .437      90.9     16.0      1.009
                          9900      .449      96.9     15.3      1.030
                          0001      .443      94.0     15.6      1.020
                          0102      .445      94.8     15.7      1.034

                          sec/poss is the avg time per team possession, pts/poss is the avg points scored per team possession. you can see a general trend in a slower game thru time (secs/poss) but no such similar trend in offensive productivity...

                          as you can see total points scored and game pace have next to nothing to do with offensive productivity per team possession. 1978-79 and 1999-00 have the same pts scored per team possession (1.029 and 1.030) yet vastly different game paces, vastly different FG%s, etc. if you should doubt these pts/poss numbers, DeanO or any other of the stats gurus in this discussion group can verify (or for that fact deny) them....

                          since i can't accurately calculate pts/poss prior to 77-78, i can't present similar evidence. but the above clearly shows that over a 24 year time span of the NBA that offensive production per team possession is not directly correlated to game pace (slowing down the game or speeding it up)......

                          And the only explanation I can deduce is that offenses were disciplining themselves (through improved coaching I surmise) and expunging bad shot selection.  Now, as
                          I also said before, I expect that defenses were also improving during this time so that the 12 point estimate is in fact a low estimate of the actual improvement in these two decades.

                          have no idea where this is coming from...

                          And to continue.  If one accepts the general and continuous improvement of the game over the two decades mentioned, then it becomes arbitrary to imagine that progress stopped then.  The reasonable prior belief is that the slow decrease in offensive productivity after this point is the result of defensive improvements, rather than some technological retrogression.

                          what slow decrease in offensive productivity? i see similar offensive productivity in 77-78 to 80-81 as i see in 97-98 to 01-02, with the higher productivity per poss of the 1980s being higher and fairly constant...

                          technological retrogression?? like what, bring back the jump ball after every score??...

                          And finally, I made what I think is a very persuasive argument for the superiority of the trained athlete in more recent times.  In the form of a question, if there are not some return to his efforts, why is he killing himself in the gym?

                          a nice philosophical arguement but not pertinent for stats analysis..

                          There is the "proof".  I look forward to any alternate explanation of these facts and inferences.

                          see above...

                          All this aside, I should say that I have nothing but the highest regard for the notion of using simulations for analyzing the game of basketball.  To my mind, they are the best method for understanding the effect of marginal changes in game variables.

                          However, they are not useful - only highly deceptive - in determining the competitiveness of NBA teams from different eras.

                          words from the wise i guess....

                          bob chaikin
                          bchaikin@...





                        • Dean Oliver <deano@rawbw.com>
                          ... points ... game thru ... productivity... ... This trend looks about right, even if my calculations have slight differences. ... disciplining ... shot ...
                          Message 12 of 29 , Jan 27, 2003
                          • 0 Attachment
                            --- In APBR_analysis@yahoogroups.com, bchaikin@a... wrote:
                            > here are some number for you to chew on:
                            >
                            > pts/ sec/ pts/
                            > year FG% 48min poss poss
                            > 7778 .469 107.7 13.4 1.000
                            > 7879 .485 109.8 13.5 1.029
                            > 7980 .481 108.5 13.8 1.041
                            > 8081 .486 107.5 14.0 1.043
                            > 8182 .491 107.9 14.1 1.058
                            > 8283 .485 107.9 13.8 1.037
                            > 8384 .492 109.2 14.0 1.063
                            > 8485 .491 110.2 13.9 1.066
                            > 8586 .487 109.5 13.9 1.059
                            > 8687 .480 109.2 14.1 1.067
                            > 8788 .480 107.6 14.3 1.065
                            > 8889 .477 108.5 14.1 1.062
                            > 8990 .476 106.3 14.4 1.065
                            > 9091 .474 105.5 14.5 1.063
                            > 9192 .472 104.5 14.7 1.067
                            > 9293 .473 104.5 14.7 1.066
                            > 9394 .466 101.0 15.0 1.049
                            > 9495 .466 100.6 15.3 1.069
                            > 9596 .462 98.8 15.5 1.063
                            > 9697 .455 96.2 15.8 1.053
                            > 9798 .450 94.8 15.7 1.036
                            > 9899 .437 90.9 16.0 1.009
                            > 9900 .449 96.9 15.3 1.030
                            > 0001 .443 94.0 15.6 1.020
                            > 0102 .445 94.8 15.7 1.034
                            >
                            > sec/poss is the avg time per team possession, pts/poss is the avg
                            points
                            > scored per team possession. you can see a general trend in a slower
                            game thru
                            > time (secs/poss) but no such similar trend in offensive
                            productivity...
                            >

                            This trend looks about right, even if my calculations have slight
                            differences.


                            >
                            > And the only explanation I can deduce is that offenses were
                            disciplining
                            > themselves (through improved coaching I surmise) and expunging bad
                            shot
                            > selection. Now, as
                            > I also said before, I expect that defenses were also improving
                            during this
                            > time so that the 12 point estimate is in fact a low estimate of the
                            actual
                            > improvement in these two decades.
                            >
                            > have no idea where this is coming from...
                            >
                            > And to continue. If one accepts the general and continuous
                            improvement of
                            > the game over the two decades mentioned, then it becomes arbitrary
                            to imagine
                            > that progress stopped then. The reasonable prior belief is that
                            the slow
                            > decrease in offensive productivity after this point is the result
                            of
                            > defensive improvements, rather than some technological
                            retrogression.
                            >
                            > what slow decrease in offensive productivity? i see similar
                            offensive
                            > productivity in 77-78 to 80-81 as i see in 97-98 to 01-02, with the
                            higher
                            > productivity per poss of the 1980s being higher and fairly
                            constant...
                            >
                            > technological retrogression?? like what, bring back the jump ball
                            after every
                            > score??...
                            >
                            > And finally, I made what I think is a very persuasive argument for
                            the
                            > superiority of the trained athlete in more recent times. In the
                            form of a
                            > question, if there are not some return to his efforts, why is he
                            killing
                            > himself in the gym?
                            >
                            > a nice philosophical arguement but not pertinent for stats
                            analysis..

                            I would say that the philosophy does have pertinence. Neither
                            philosophy nor stats can live in an isolated world. Too often,
                            statistical results are interpreted blind of the rest of the world,
                            which is why oat bran is good for you one week and deadly the next.
                            It comes down to where the burden of proof lies. I think there is a
                            significant burden for stats to carry because they already have the
                            word "lies" associated with them. If stats don't see what others see
                            very clearly, they not only have to say why they don't see them, they
                            have to show that they've tried every means to see them, and then
                            they have to really show why people are deceived by their eyes.

                            Right now, Bob is implying that the burden is not on the stats to
                            show that cross-generational sims are reliable, but I would say that
                            it is. How a simulation should handle different rules hasn't been
                            answered. How a simulation should handle different average heights
                            and weights hasn't been answered. How a simulation should handle the
                            very different league averages in pace or points per possession
                            hasn't been answered. Setting up frameworks for these philosophical
                            questions is relevant for trusting any simulation.


                            DeanO
                          • schtevie2003 <schtevie@hotmail.com>
                            Okay, let s take things point by point and be done with it? ... counterpart ... pace). This is ... league average. ... from....how did you ... Me again: The
                            Message 13 of 29 , Jan 27, 2003
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                              Okay, let's take things point by point and be done with it?

                              Me:

                              > the superiority of the average team in the early 80 to its 60s
                              counterpart
                              > was on
                              > the order of 10 to 12 points per game (at a modern game
                              pace). This is
                              > equivalent to how much better the best Bulls team was to the
                              league average.

                              Bob:

                              > not sure what these numbers mean or where they are coming
                              from....how did you
                              > arrive at this or derive these numbers?...

                              Me again: The calculation I referred to was made by computing
                              a measure of offensive (or equivalently defensive) productivity
                              that I called "points per common possession" versus "common
                              possessions per game". In the former case, the computation is
                              average points scored in the numerator and average common
                              possessions in the denominator. Common possessions are,
                              by definition and construction, the same for both teams in a
                              particular game (hence attractive for purposes of comparison
                              and analysis) and are basically calculated by subtracting the
                              number of offensive rebounds from the conventionally defined
                              number of possessions a team enjoys in a game.

                              For missing data series internal to the sums (that is for
                              turnovers and offensive rebounds in the time periods in
                              question) as I noted before, I extrapolated values and conducted
                              a bit of sensitivity analysis to see if reasonable deviations from
                              assumed values would overturn results. They could not. (As
                              noted, the offensive rebounding percentage was remarkably
                              stable over succeeding time period.)

                              Finally, the "12 points per game" was, if I recall correctly, taking
                              the observed increase in productivity and prorating it at the
                              modern end-point game pace. (Which is to say it would have
                              been higher using the earlier endpoint where there were more
                              possessions per game, but no more meaningful.)

                              Then to repeat, "what the numbers mean" is that teams were
                              having fewer possessions (defined to encompass all they would
                              do with the ball before it would revert to the opposing team) per
                              game yet they were scoring more points. These are the
                              off-setting trends that allow no other explanation (yet offered)
                              than the offenses were - on net - getting better, much better.

                              ******************

                              Me:

                              > Just looking at the average offensive productivity over the time
                              in question,
                              > what one sees is that it improved dramatically (the 12 points
                              per game
                              > above).

                              Bob:

                              > would love to "look" at it but you're not showing anything...

                              Me again: As noted, I did not have these data on file or in hand,
                              as they were done long ago. Perhaps I will spend the time to
                              recalculate them. In the meantime, if you have these data at your
                              fingertips, feel free to make the calculation. There is no
                              ambiguity as to what they say. The trends are almost strictly
                              monotonic as I recall. Pick any starting year in the mid to early
                              60s (or late 50s for that matter) and any end point in the late 70s
                              to early 80s. The numbers speak clearly.

                              **************************

                              Me:

                              > Now, those who believe we stand on the shoulders of giants
                              might be inclined
                              > to say that defenses got worse as opposed to offenses having
                              improved. Is
                              > this view tenable? The answer is "no" because the trend is
                              accompanied by a
                              > dramatic slowing of the game. This slowing, all else equal,
                              implies that
                              > offensive productivity should have decreased. . Why? It either
                              means
                              > fast-break baskets were being reduced or that the half-court
                              offenses were
                              > having to work harder for shots. But offenses improved,
                              dramatically...

                              Bob:

                              > here are some number for you to chew on:
                              >
                              > pts/ sec/ pts/
                              > year FG% 48min poss poss
                              > 7778 .469 107.7 13.4 1.000
                              > 7879 .485 109.8 13.5 1.029
                              > 7980 .481 108.5 13.8 1.041
                              > 8081 .486 107.5 14.0 1.043
                              > 8182 .491 107.9 14.1 1.058
                              > 8283 .485 107.9 13.8 1.037
                              > 8384 .492 109.2 14.0 1.063
                              > 8485 .491 110.2 13.9 1.066
                              > 8586 .487 109.5 13.9 1.059
                              > 8687 .480 109.2 14.1 1.067
                              > 8788 .480 107.6 14.3 1.065
                              > 8889 .477 108.5 14.1 1.062
                              > 8990 .476 106.3 14.4 1.065
                              > 9091 .474 105.5 14.5 1.063
                              > 9192 .472 104.5 14.7 1.067
                              > 9293 .473 104.5 14.7 1.066
                              > 9394 .466 101.0 15.0 1.049
                              > 9495 .466 100.6 15.3 1.069
                              > 9596 .462 98.8 15.5 1.063
                              > 9697 .455 96.2 15.8 1.053
                              > 9798 .450 94.8 15.7 1.036
                              > 9899 .437 90.9 16.0 1.009
                              > 9900 .449 96.9 15.3 1.030
                              > 0001 .443 94.0 15.6 1.020
                              > 0102 .445 94.8 15.7 1.034
                              >
                              > sec/poss is the avg time per team possession, pts/poss is the
                              avg points
                              > scored per team possession. you can see a general trend in a
                              slower game thru
                              > time (secs/poss) but no such similar trend in offensive
                              productivity...
                              >
                              > as you can see total points scored and game pace have next to
                              nothing to do
                              > with offensive productivity per team possession. 1978-79 and
                              1999-00 have the
                              > same pts scored per team possession (1.029 and 1.030) yet
                              vastly different
                              > game paces, vastly different FG%s, etc. if you should doubt
                              these pts/poss
                              > numbers, DeanO or any other of the stats gurus in this
                              discussion group can
                              > verify (or for that fact deny) them....
                              >
                              > since i can't accurately calculate pts/poss prior to 77-78, i can't
                              present
                              > similar evidence. but the above clearly shows that over a 24
                              year time span
                              > of the NBA that offensive production per team possession is
                              not directly
                              > correlated to game pace (slowing down the game or speeding
                              it up)......

                              Me again: I have chewed on your numbers,and I am happty to tell
                              you what flavor impressions they leave. First, I should say that
                              the food is not what I ordered. You pick as a starting point of your
                              series, the end point of the trend I asserted. No matter. Let's
                              talk about what you present. First of all, I am not sure how you
                              calculate possessions, but never mind. As I recall my rendering
                              of the data in the timespan you present (and again, these are
                              somewhat distant recollections) once you factor out the
                              increasing weight of the three-point shot in augmenting average
                              offensive productivity (as I noted previously, in passing, it took a
                              remarkably long time for teams to figure out how to optimize the
                              three point shot in the context of team offenses) what the 80s
                              represents is a period of essential "stagnation" (neither offenses
                              or defenses gaining at the expense of the other) followed by a
                              decline beginning in the very late 80s or early 90s. Now, nothing
                              you present overturns this impression of mine. And as to these
                              changes in the 90s, taking the data you present above (let's say
                              '91-'92 to '01-'02) what they say is that there was a 6.8% increase
                              in seconds per possession and a 3.1% decrease in points per
                              possession. At 91.72 possessions per game in '01-02 this
                              means teams were scoring 3 points per game less than the
                              decade prior. If this represents a net improvement in average
                              defense over the decade, Is there anyone who doesn't think that
                              that is significant? Again, for context, the average NBA champion
                              is only about 6 to 7 points (again pace dependent, blah, blah,
                              blah) than the average team in the league. So 3 points is close
                              to half the way from mediocrity to championship status.

                              *********************

                              Me:

                              > And the only explanation I can deduce is that offenses were
                              disciplining
                              > themselves (through improved coaching I surmise) and
                              expunging bad shot
                              > selection. Now, as
                              > I also said before, I expect that defenses were also improving
                              during this
                              > time so that the 12 point estimate is in fact a low estimate of
                              the actual
                              > improvement in these two decades.

                              Bob:

                              > have no idea where this is coming from...

                              Me again: About what have you no idea? Is it the deduction that
                              the offsetting trends of game pace and offensive productivity in
                              the 60s and 70s necessarily mean (again, absent an alternative
                              explanation) that there is a net offensive improvement in the
                              average NBA team over time? If so, I don't know how to explain it
                              any more clearly. Perhaps someone else can help.

                              Or is it the point that the "12 point" estimate is a low-ball? This
                              simply means that all the offsetting trends can identify is the net
                              offensive improvement. Now one can believe then that the
                              relentless assault of offenses on defenses were met with no
                              countermoves on the latter's part. In this case, the estimate is
                              not low, but this of course seems rather hard to believe, hence
                              the low-ball claim.

                              ***************

                              Me:

                              > And to continue. If one accepts the general and continuous
                              improvement of
                              > the game over the two decades mentioned, then it becomes
                              arbitrary to imagine
                              > that progress stopped then. The reasonable prior belief is that
                              the slow
                              > decrease in offensive productivity after this point is the result of
                              > defensive improvements, rather than some technological
                              retrogression.

                              Bob:

                              > what slow decrease in offensive productivity? i see similar
                              offensive
                              > productivity in 77-78 to 80-81 as i see in 97-98 to 01-02, with
                              the higher
                              > productivity per poss of the 1980s being higher and fairly
                              constant...
                              >
                              > technological retrogression?? like what, bring back the jump
                              ball after every
                              > score??...

                              Me again: Again, I refer you to the fact that the endpoints you
                              chose for your analysis were not the period I was speaking of.
                              But additionally, to repeat somewhat, your selection is rather
                              precious, as there is a lot going on over the 15 year period you
                              show. Productivity goes up and down again.

                              And as for the term "technological retrogression", I am sorry that
                              it confused you. I was simply pointing out (regarding the 90s
                              decrease in offensive productivity) that the alternative to believing
                              that defenses had on net improved relative to offenses, one
                              must believe that somehow offenses got worse, somehow
                              forgetting to do as well in a given year what they could do a few
                              years past (that is to say that their "technology" - the means by
                              which they produce points - had retrogressed - as opposed to
                              progressed). Clear?

                              ********************

                              Me:

                              > And finally, I made what I think is a very persuasive argument
                              for the
                              > superiority of the trained athlete in more recent times. In the
                              form of a
                              > question, if there are not some return to his efforts, why is he
                              killing
                              > himself in the gym?

                              Bob:

                              > a nice philosophical arguement but not pertinent for stats
                              analysis..

                              Me again: Are you kidding me? Statistics are a useful and
                              indispensible tool for divining truth, but they are not the sole
                              means; no matter if they are your fetish of this paragraph in this
                              argument. As for numbers, the point was made, and made
                              unanswered, that in every athletic endeavor where competition is
                              additionally against a fixed measure (say 100 yds run, or pounds
                              lifted, or spins in air completed) there has been a relentless yet
                              decreasing improvement over time. You seem to plead specially
                              for basketball's exception when it is observed that its athletes
                              are bigger and stronger. And as for the question I pose
                              regarding why a rational athlete would devote excruciating hours
                              in a gym to no benefit, it is also pertinent for the analysis.

                              ***************

                              Me:

                              > There is the "proof". I look forward to any alternate explanation
                              of these
                              > facts and inferences.

                              Bob:

                              > see above...

                              Me again: See above indeed.

                              *************************

                              Me:

                              > All this aside, I should say that I have nothing but the highest
                              regard for
                              > the notion of using simulations for analyzing the game of
                              basketball. To my
                              > mind, they are the best method for understanding the effect of
                              marginal
                              > changes in game variables.
                              >
                              > However, they are not useful - only highly deceptive - in
                              determining the
                              > competitiveness of NBA teams from different eras.

                              Bob:

                              > words from the wise i guess....

                              Me again: see above...
                            • bchaikin@aol.com
                              I would say that the philosophy does have pertinence. Neither philosophy nor stats can live in an isolated world. Too often, statistical results are
                              Message 14 of 29 , Jan 27, 2003
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                                I would say that the philosophy does have pertinence. Neither philosophy nor stats can live in an isolated world. Too often, statistical results are interpreted blind of the rest of the world, which is why oat bran is good for you one week and deadly the next.
                                It comes down to where the burden of proof lies. I think there is a significant burden for stats to carry because they already have the word "lies" associated with them. If stats don't see what others see very clearly, they not only have to say why they don't see them, they have to show that they've tried every means to see them, and then
                                they have to really show why people are deceived by their eyes.

                                well then i guess the question in this instance is what are the stats - all the stats available - telling us? if someone persists in stating that lower scoring per game, for instance, means lower (or higher, or better) offensive productivity, and that this is how he defines offensive productivity, and at the same time this individual also states that "...i expect that defenses were also improving...", how can you have both without showing the process as a whole is "improving"?......if we can show thru other statistical methods that offensive productivity has not improved with time, such as with league averages for pts/poss, and they choose not to believe it, then why a stats analysis discussion group?...

                                without taking into consideration other statistical evidence provided, then again we are looking at some one saying the sun does not set in the west and refusing to look to the west to see it. in other words, then just what is he saying? arguement for the sake of arguement?....

                                Yup, compared to the 1970s, we see more switching on defense, better team defense. Better team offense too...better defensive rotations too.

                                again someone states a similar arguement, better offense and better defense, but neither arguement backs up their statements with any sort of statistical evidence. if i was to state that 20 or 30 or 40 years ago both offense and defense were actually better than today (which i am not) everyone would say to prove it, but these quotes simply assume they are correct and do not feel the need to show any kind of statistical evidence....

                                Right now, Bob is implying that the burden is not on the stats to show that cross-generational sims are reliable, but I would say that it is. How a simulation should handle different rules hasn't been answered.

                                again, have rule changes affected the game in a way measurable statistically? has defensive 3 sec, the convoluted zone rules of the lates 80s early 90s, the recent zone defenses, changed say FG% differently than before, altered pts/poss differently than before? these parameters have fluctuated over time (at least from 77-78 to today) but i can see no discernable connection between their fluctuation/changing and any specific rules changes - the process as i see it appears the same. can you show a correlation to a rule change affecting the game in a measurable way? other than when they brought in the 3pt line, which in itself increased 3pt FGA (decreased 2pt FGA) and increased 3pt FG%, the league overall FG% and say pts/poss did not appear to be affected by the rule change..

                                How a simulation should handle different average heights and weights hasn't been answered.

                                every season NBA teams of varying heights and weights play each other, and that doesn't seem to cause any problems. is there some sort of discernable pattern to equate an advantage or disadvantage statistically in the span of one season such that NBA teams of varying hts and wts cannot be compared directly? if so state it, if not then why should this be an impediment to more than one season of comparisons?...

                                How a simulation should handle the very different league averages in pace or points per possession hasn't been answered.

                                no? then how can a simulation handle them within even the same season? again the 90-91 season is a prime example. the evidence is there, you can state that the question "...hasn't been answered..." but in fact, over the span of a single season, it has. what is the impediment in playing the 115 poss/g 90-91 nuggets versus the 93 poss/g 90-91 pistons? the bottom line is that this actually occurred in the same season, and can be modeled - its in the same season, the game paces are very different, so different in fact that its comparable to the game pace of a much longer time span than just a single season....

                                Setting up frameworks for these philosophical questions is relevant for trusting any simulation.

                                fine, are you saying the frameworks can be set up then? or no? and why?...

                                we now have 6'10" players who can dribble and pass the ball, and better rotation of the ball by even the weak teams...

                                "....6'10" players who can dribble and pass the ball...." this is evidence? as if in the late 1950s and 1960s 6'10" players who could score big time couldn't pass and/or dribble? shaquille o'neal gets probably 90% of his points from within the paint, but he sure can dribble and is a helluva passer too - as were players in their prime like walt bellamy (6'10"), bob petit (6'9"), elvin hayes (6'9"), dolph schayes (6'8"), and maurice stokes (6'7") and many others. this idea that players back then were lumbering giants scoring only because they were big and close to the basket is ridiculous.....schayes never stopped moving, hayes was as quick as a cat when he was young, bellamy averaged just under 30 pts/g his 1st 3 seasons in the league facing chamberlain and russell quite often each year (only 9 teams in the league) -although i'll admit watching him in the early/mid 1970s he really appeared to be dragging his caboose around the court...

                                better rotation of the ball? basketball of the late 1950s and 1960s was a faster paced game than today, and from watching tapes it appears more overall passing and more player movement without the ball, not as much standing around as this past decade.....not a better game, just a different style, one that required just as talented an athlete as does today's game....and athletes that could withstand the rigors of an 80-82 games season just as today...

                                This doesn't preclude cross-generation simulation, but figuring out what the game pace would be between say the 1977 Nuggets and 2003 Nuggets, and how that pace would affect each team's offensive and defensive efficiency, is a tough analytical problem.

                                again, why is this a tough analytical problem? we can sim in-season teams of varying game paces, why not consecutive seasons, seasons 2-3 years apart, seasons 5-10 years apart, seasona 20-30 years apart? what says that you can't do this? and do it accurately?

                                bob chaikin
                                bchaikin@...





                              • John Hollinger <alleyoop2@yahoo.com>
                                Bob s challenge to prove this got me thinking more about how basketball has changed in the last 30 years, such that players from 30-50 years ago wouldn t be as
                                Message 15 of 29 , Jan 27, 2003
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                                  Bob's challenge to prove this got me thinking more about how
                                  basketball has changed in the last 30 years, such that players from
                                  30-50 years ago wouldn't be as successful if they played today -- my
                                  premise being that a guy like Dave DeBusschere or Bailey Howell would
                                  be less effective today than he was then, even after adjusting for
                                  weights, diet, jets, etc.

                                  The more I think about it, the answer is that the talent pool has
                                  massively expanded.

                                  There have been three expansions of the pool in NBA history, two well-
                                  known and one not. The first was the breaking of the color bar in the
                                  1950s, which let guys Russell and Chamberlain and the Big O into the
                                  league. The third was the advent of the international player in the
                                  1980s and 1990s, an expansion that is still continuing.

                                  But the one that had the biggest impact and is least talked about is
                                  the second one -- the desegratation of the South.

                                  Try to find a significant African-American player from the South
                                  before 1960. Your list will consist of Sam Jones. All the other guys -
                                  - Wilt, Russell, Big O, etc. -- from the north or west.

                                  By 1970, just six more guys had joined Sam Jones: Wes Unseld, Willis
                                  Reed, Walt Bellamy, Walt Frazier, Elvin Hayes and Lou Hudson.

                                  So there were seven impact African-American players from the South in
                                  the NBA in 1970, and zero international players.

                                  ************


                                  Fast forward to today. The entire Eastern Conference All-Star team
                                  consists of African-Americans from the South. Two of the West's
                                  starters are international, and one other is from the South
                                  (Garnett). That's 8 of the 10 starters in the All-Star game. And if
                                  you thought Shaq should start ahead of Yao it's still 8 out of 10.

                                  None of these guys would have been playing 30-40 years ago, because
                                  their route was blocked. The major universities, most notably
                                  Kentucky, were fielding all-white teams until around 1970, and
                                  using 'one black starter' or similar quotas well afterward. As a
                                  result, the change that started with the arrival of Unseld and
                                  Frazier in the late 60s took 20 years to ripple its way through the
                                  entire league.


                                  To see how it changed it, make a list of the most dominant players of
                                  the last decade or two and then choose sides:

                                  The international/southern blacks team has:

                                  -- Hakeem Olajuwon. Shaquille O'Neal. Michael Jordan. Charles
                                  Barkley. Scottie Pippen. Clyde Drexler. Alex English. Joe Dumars.
                                  Dale Ellis. Derek Harper. Mo Cheeks. Jeff Malone. Sidney Moncrief.
                                  Robert Parish. Dennis Rodman. Dominique Wilkins. James Worthy. Ray
                                  Allen. Tim Duncan. Dirk Nowitzki. Kevin Garnett. Penny Hardaway.
                                  Allen Iverson. Shawn Kemp. Karl Malone. Toni Kukoc. Antonio McDyess.
                                  Tracy McGrady. Alonzo Mourning. Dikembe Mutombo. Jermaine O'Neal.
                                  Mitch Richmond. Ben Wallace. Arvydas Sabonis.

                                  The white north american/northern blacks team has:

                                  -- Larry Bird. Isiah Thomas. Adrian Dantley. David Robinson. Patrick
                                  Ewing. Kevin Johnson. Magic Johnson. Kobe Bryant. Chris Mullin. Tim
                                  Hardaway. Grant Hill. Jason Kidd. Gary Payton. Stephon Marbury.
                                  Reggie Miller. Steve Nash. Paul Pierce. Glen Rice. David Robinson.
                                  John Stockton. Antoine Walker. Rasheed Wallace. Chris Webber. Kevin
                                  Willis.

                                  It's no contest, right?

                                  The massive influx of quality players who previously had no access to
                                  the path to the professional game -- either because nobody in their
                                  country played or because of Jim Crow -- is the reason I think there
                                  is a major difference in the quality of play between 30 years ago and
                                  now. More than half the good players in the league simply wouldn't be
                                  there if it was 1970.
                                • bchaikin@aol.com
                                  Okay, let s take things point by point and be done with it? if you tire of the exchange of ideas concerning this discussion, once you have already made your
                                  Message 16 of 29 , Jan 27, 2003
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                                    Okay, let's take things point by point and be done with it?

                                    if you tire of the exchange of ideas concerning this discussion, once you have already made your position clear, but do not wish to be bothered to be asked to defend your postion with stats in a stats analysis group, then maybe this wasn't the forum for you to "...add a few pennies worth of thought on the issue of inter-temporal comparsions of NBA performance..."...

                                    Me:

                                    the superiority of the average team in the early 80 to its 60s counterpart was on the order of 10 to 12 points per game (at a modern game pace).  This is equivalent to how much better the best Bulls team was to the league average.

                                    Bob:

                                    not sure what these numbers mean or where they are coming from....how did you arrive at this or derive these numbers?...

                                    so let me get this straight, you are saying you have statistically come up with a way to show that if the average NBA team of the early 1980s (about 109 pts/g) played an average team from the 1960s (115 pts/g) or early 1960s (almost 116 pts/g), the avg 80s team would beat the average 60s team, on average, by 10-12 points, normalizing for modern times. the 95-96 bulls outscored their opponents that year by just over 12 pts/g. so you are saying the difference in ability to win of an average early 1980s NBA team versus/compared to an average 1960s or early 1960s is the same as the 95-96 bulls to the suns or hornets of 95-96 (.500 teams that year)...

                                    is this correct?...

                                    Me again:  The calculation I referred to was made by computing a measure of offensive (or equivalently defensive) productivity that I called "points per common possession" versus "common possessions per game".  In the former case, the computation is average points scored in the numerator and average common
                                    possessions in the denominator.  Common possessions are, by definition and construction, the same for both teams in a particular game (hence attractive for purposes of comparison and analysis) and are basically calculated by subtracting the number of offensive rebounds from the conventionally defined number of possessions a team enjoys in a game.

                                    fine...so fill in the blanks below so we can compare...or show us your numbers that show how you arrived at your result...

                                                             pts/      sec/      pts/
                                    year        FG%      g      poss     poss
                                    5960      .410     115.3
                                    6061      .415     118.1
                                    6162      .426     118.8
                                    6263      .441     115.3
                                    6364      .433     111.0
                                    6465      .426     110.6
                                    6566      .433     115.5
                                    6667      .441     117.4
                                    6768      .446     116.6
                                    6869      .441     112.3
                                    6970      .460     116.7
                                    7071      .449     112.4
                                    7172      .455     110.2
                                    7273      .456     107.6
                                    7374      .459     105.7
                                    7475      .457     102.3
                                    7576      .458     104.3
                                    7677      .465     106.5

                                                             pts/
                                                             48min
                                    7778      .469     107.7    13.4      1.000
                                    7879      .485     109.8    13.5      1.029
                                    7980      .481     108.5    13.8      1.041   
                                    8081      .486     107.5    14.0      1.043
                                    8182      .491     107.9    14.1      1.058
                                    8283      .485     107.9    13.8      1.037
                                    8384      .492     109.2    14.0      1.063
                                    8485      .491     110.2    13.9      1.066
                                    8586      .487     109.5    13.9      1.059
                                    8687      .480     109.2    14.1      1.067
                                    8788      .480     107.6    14.3      1.065
                                    8889      .477     108.5    14.1      1.062
                                    8990      .476     106.3    14.4      1.065
                                    9091      .474     105.5    14.5      1.063
                                    9192      .472     104.5    14.7      1.067
                                    9293      .473     104.5    14.7      1.066
                                    9394      .466     101.0    15.0      1.049
                                    9495      .466     100.6    15.3      1.069
                                    9596      .462      98.8     15.5      1.063
                                    9697      .455      96.2     15.8      1.053
                                    9798      .450      94.8     15.7      1.036
                                    9899      .437      90.9     16.0      1.009
                                    9900      .449      96.9     15.3      1.030
                                    0001      .443      94.0     15.6      1.020
                                    0102      .445      94.8     15.7      1.034

                                    DeanO has pointed out that "...this trend looks about right, even if my calculations have slight differences...". so if we are defining offensive productivity as pts/poss, i see similar pts/poss numbers with varying FG% and pts/g and game pace for 77-78 thru today. if your number show a different trend for prior to 77-78, lets see them...

                                    For missing data series internal to the sums (that is for turnovers and offensive rebounds in the time periods in question) as I noted before, I extrapolated values

                                    fine - you made some assumptins/estimates for missing parameters...

                                    and conducted a bit of sensitivity analysis to see if reasonable deviations from
                                    assumed values would overturn results. 

                                    overturn what results, your 10-12 pts spread?...

                                    They could not. (As noted, the offensive rebounding percentage was remarkably stable over succeeding time period.)

                                    Finally, the "12 points per game" was, if I recall correctly, taking he observed increase in productivity and prorating it at the modern end-point game pace. (Which is to say it would have been higher using the earlier endpoint where there were more
                                    possessions per game, but no more meaningful.)

                                    so lets see how you came up with this using the your numbers....

                                    Then to repeat, "what the numbers mean" is that teams were having fewer possessions (defined to encompass all they would do with the ball before it would revert to the opposing team) per game yet they were scoring more points. 

                                    lets see some numbers to back this up...

                                    These are the off-setting trends that allow no other explanation (yet offered) than the offenses were - on net - getting better, much better.

                                    this is how you defend your position, by stating that the results allow "...no other explanation..."?

                                    Me:

                                    Just looking at the average offensive productivity over the time in question, what one sees is that it improved dramatically (the 12 points per game above).

                                    Bob:

                                    would love to "look" at it but you're not showing anything...

                                    Me again: As noted, I did not have these data on file or in hand, as they were done long ago.  Perhaps I will spend the time to recalculate them.  In the meantime, if you have these data at your fingertips, feel free to make the calculation. 

                                    feel free to explain it...

                                    There is no ambiguity as to what they say.  The trends are almost strictly monotonic as I recall.  Pick any starting year in the mid to early 60s (or late 50s for that matter) and any end point in the late 70s to early 80s.  The numbers speak clearly.

                                    show me the beef.....

                                    Me:

                                    Now, those who believe we stand on the shoulders of giants might be inclined to say that defenses got worse as opposed to offenses having mproved.  Is this view tenable?  The answer is "no" because the trend is accompanied by a dramatic slowing of the game. 

                                    the answer is not "no", the numbers from 77-78 thru today show that the slowing of the game does not correlate well with pts/poss, on the contrary from 77-78 thru today the values fluctuate from 1.000 to the early 90s there is an increase to almost 1.070. 77-78 and 98-99 show very close pts/poss numbers of 1.000 and 1.009 yet the game pace is significantly different. based on that why should anyone believe your pre-77-78 numbers without seeing them?....

                                    This slowing, all else equal, implies that offensive productivity should have decreased. .  Why?  It either means fast-break baskets were being reduced or that the half-court offenses were having to work harder for shots.  But offenses improved, dramatically...

                                    sorry, don't see it....

                                    Bob:

                                    here are some number for you to chew on:

                                                            pts/      sec/      pts/
                                    year        FG%   48min   poss     poss
                                    7778      .469     107.7    13.4      1.000
                                    7879      .485  109.8    13.5      1.029
                                    7980      .481     108.5    13.8      1.041 
                                    8081      .486     107.5    14.0      1.043
                                    8182      .491  107.9    14.1      1.058
                                    8283      .485     107.9    13.8      1.037
                                    8384      .492     109.2    14.0      1.063
                                    8485      .491     110.2    13.9      1.066
                                    8586      .487     109.5    13.9      1.059
                                    8687      .480     109.2    14.1      1.067
                                    8788      .480     107.6    14.3      1.065
                                    8889      .477     108.5    14.1      1.062
                                    8990      .476     106.3    14.4      1.065
                                    9091      .474     105.5    14.5      1.063
                                    9192      .472     104.5    14.7      1.067
                                    9293      .473     104.5    14.7      1.066
                                    9394      .466     101.0    15.0      1.049
                                    9495      .466     100.6    15.3      1.069
                                    9596      .462      98.8     15.5      1.063
                                    9697      .455      96.2     15.8      1.053
                                    9798      .450      94.8     15.7    1.036
                                    9899      .437      90.9     16.0      1.009
                                    9900      .449      96.9     15.3      1.030
                                    0001      .443      94.0     15.6    1.020
                                    0102      .445      94.8     15.7      1.034

                                    sec/poss is the avg time per team possession, pts/poss is the avg points scored per team possession. you can see a general trend in a slower game thru time secs/poss) but no such similar trend in offensive productivity...

                                    as you can see total points scored and game pace have next to nothing to do with offensive productivity per team possession. 1978-79 and 1999-00 have the same pts scored per team possession (1.029 and 1.030) yet vastly different game paces, vastly different FG%s, etc. if you should doubt these pts/poss numbers, DeanO or any other of the stats gurus in this discussion group can verify (or for that fact deny) them....

                                    since i can't accurately calculate pts/poss prior to 77-78, i can't present similar evidence. but the above clearly shows that over a 24 year time span of the NBA that offensive production per team possession is not directly correlated to game pace (slowing down the game or speeding it up)......

                                    Me again: I have chewed on your numbers,and I am happty to tell you what flavor impressions they leave.  First, I should say that the food is not what I ordered.  You pick as a starting point of your series, the end point of the trend I asserted. 

                                    the stats are available from 77-78 on, you haven't presented your numbers nor estimates for data missing prior to that. are we to simply take your word on it?...

                                    No matter.  Let's talk about what you present.  First of all, I am not sure how you
                                    calculate possessions, but never mind. 

                                    i don't know how you or DeanO do either, but apparently his and my numbers are similar...

                                    As I recall my rendering of the data in the timespan you present (and again, these are somewhat distant recollections) once you factor out the increasing weight of the three-point shot in augmenting average offensive productivity (as I noted previously, in passing, it took a remarkably long time for teams to figure out how to optimize the three point shot in the context of team offenses) what the 80s represents is a period of essential "stagnation" (neither offenses or defenses gaining at the expense of the other) followed by a decline beginning in the very late 80s or early 90s. 

                                    this i do not see...i see similar pts/poss for early 1980s to mid 1990s...and similar numbers for late 70s and late 90s early 2000s.....if you have different numbers for offensive productivity lets see them to back up your statements...

                                    Now, nothing you present overturns this impression of mine. 

                                    surprising...

                                    And as to these changes in the 90s, taking the data you present above (let's say '91-'92 to '01-'02) what they say is that there was a 6.8% increase in seconds per possession and a 3.1% decrease in points per ossession. 

                                    from 89-90 to 96-97 i see simlar pts/poss numbers but a game consistently slowing down...no correlation there.....i see a lowering of pts/poss in the next 5 years but it fluctuates, no discernable pattern...

                                    At 91.72 possessions per game in '01-02 this means teams were scoring 3 points per game less than the decade prior. 

                                    in 01-02 the 1.034 pts/poss is similar to the 82-83 pts/poss of 1.037, yet they scored
                                    more points per game in 82-83 (108 pts/g vs 95 pts/g) simply becuase the game pace was faster...

                                    If this represents a net improvement in average defense over the decade, Is there anyone who doesn't think that that is significant? 

                                    looks to me like a fluctuation of pts/poss over a 24 season period, despite a general slowing of game pace...

                                    in 78-79 i see .485 FG%, 110 pts/g, and 13.5 sec/poss with 1.029 pts/poss. in 99-00 i see .449 FG%, 97 pts/g, 15.3 sec/poss, but the same pts/poss of 1.030....are we not looking at the same data?...

                                    Again, for context, the average NBA champion is only about 6 to 7 points (again pace dependent, blah, blah, blah) than the average team in the league.  So 3 points is close to half the way from mediocrity to championship status.

                                    not sure what you point is again...

                                    Me:

                                    And the only explanation I can deduce is that offenses were disciplining themselves (through improved coaching I surmise) and expunging bad shot selection.  Now, as
                                    > I also said before, I expect that defenses were also improving during this time so that the 12 point estimate is in fact a low estimate of the actual improvement in these two decades.

                                    Bob:

                                    have no idea where this is coming from...

                                    Me again: About what have you no idea? Is it the deduction that the offsetting trends of game pace and offensive productivity in the 60s and 70s

                                    show us some data...

                                    necessarily mean (again, absent an alternative explanation) that there is a net offensive improvement in the average NBA team over time?  If so, I don't know how to explain it any more clearly.  Perhaps someone else can help.

                                    perhaps...

                                    Or is it the point that the "12 point" estimate is a low-ball?  This simply means that all the offsetting trends can identify is the net offensive improvement.  Now one can believe then that the relentless assault of offenses on defenses were met with no
                                    countermoves on the latter's part.  In this case, the estimate is not low, but this of course seems rather hard to believe, hence the low-ball claim.

                                    Me:

                                    And to continue.  If one accepts the general and continuous improvement of the game over the two decades mentioned, then it becomes arbitrary to imagine that progress stopped then.  The reasonable prior belief is that the slow decrease in offensive productivity after this point is the result of defensive improvements, rather than some technological
                                    retrogression.

                                    you've made a number of generalizations...show us when - what years - the trend increased, with yearly numbers, when it stopped, when it decreased, etc....may be obvious to you, but you are not being definitive. the above 77-78 to 01-02 numbers show otherwise...

                                    unless of course you are not defining offensive productivity with pts/poss but something else...

                                    Bob:

                                    what slow decrease in offensive productivity? i see similar offensive productivity in 77-78 to 80-81 as i see in 97-98 to 01-02, with the higher productivity per poss of the 1980s being higher and fairly constant...

                                    technological retrogression?? like what, bring back the jump ball after every score??...

                                    e again: Again, I refer you to the fact that the endpoints you chose for your analysis were not the period I was speaking of. 

                                    actual data for ast, st, bs doesn't exist for prior to 73-74 (except ABA) and TO prior to 77-78. you say you've made estimates for seasons prior to this but don't show them, and present your findings as dogma...

                                    But additionally, to repeat somewhat, your selection is rather precious, as there is a lot going on over the 15 year period you show.  Productivity goes up and down again.

                                    24 year period - while there is a general increase in time per poss, or decrease in game pace - no definitive pattern for pts/poss or offensive productivity versus game pace for this 24 year period is evident...and you want us to believe - that without you showing the data - that there is a trend for seasons prior to this...

                                    And as for the term "technological retrogression", I am sorry that it confused you.  I was simply pointing out (regarding the 90s decrease in offensive productivity)

                                    you mean 97-98 to 01-02 don't you?...

                                    that the alternative to believing that defenses had on net improved relative to offenses, one must believe that somehow offenses got worse, somehow forgetting to do as well in a given year what they could do a few years past (that is to say that their "technology" - the means by which they produce points - had retrogressed - as opposed to progressed).  Clear?

                                    if you say so...

                                    Me:

                                    And finally, I made what I think is a very persuasive argument for the superiority of the trained athlete in more recent times.  In the form of a question, if there are not some return to his efforts, why is he killing himself in the gym?

                                    Bob:

                                    a nice philosophical arguement but not pertinent for stats analysis..

                                    in 73-74 nate archibald was making $400,000 a year. the average salary (not mean but average) at the time was - i'm guessing - 1/8 to 1/4 of that, somewhere in between $50,000 to $100,000. the average american income for a working adult at that time was probably about $5,000 - $15,000 a year. for that kind of scratch are you saying athletes didn't keep themselves in shape, in condition, to play pro hoops? that that kind of dough wasn't enough incentive to also kill themselves in the gym in the early 1970s like athletes kill themselves today? i don't know the average salaries in the early 1960s, but i know chamberlain and russell were arounf $100,000, and i'll bet the league avg salary was well above the average working adult salary at the time - and this doesn't take into account the salary war started by the ABA in the late 60s early 70s.....i'm also guessing the average player trying to make the NBA in the early 60s (let alone today), if he didn't make it, went on to become a doctor or lawyer with a high salary...

                                    just becuase the athlete of the 1960s didn't have access to the weight training they had today and all the equipment doesn't mean they didn't do whatever they could to be inshape to play at the pro level...

                                    Me again:  Are you kidding me?  Statistics are a useful and indispensible tool for divining truth, but they are not the sole means; no matter if they are your fetish of this paragraph in this argument.  As for numbers, the point was made, and made
                                    unanswered, that in every athletic endeavor where competition is additionally against a fixed measure (say 100 yds run, or pounds lifted, or spins in air completed) there has been a relentless yet decreasing improvement over time. 

                                    so absolute records are broken against static measures. basketball is a relative measure, player versus player, like baseball or any of the other team sports. the arguement is pointless. are the players better athletes - better bodies, better nutrition - yes im sure, but better basketball players? if no one breaks wayne gretzky's records in the next 100 years, does that mean hockey had peaked in athletic performnace in the early to mid 1980s??

                                    You seem to plead specially for basketball's exception when it is observed that its athletes are bigger and stronger.  And as for the question I pose regarding why a rational athlete would devote excruciating hours in a gym to no benefit, it is also pertinent for the analysis. 

                                    the assumption that pro basketball athletes train harder and longer now than 10, 20 or 30 years ago is ridiculous. players back in the 60s and 70s and late 50s ran just as much in practice, played 35+ or 40+ min/g just like they do today, at an even faster paced game...they all saw the benefit of good training, to make an excellent living. every generation has its hotplate williams and oliver millers, as they have their dolph schayes and john havliceks and john stocktons and karl malones...

                                    Me:

                                    There is the "proof".  I look forward to any alternate explanation of these facts and inferences.

                                    Bob:

                                    see above...

                                    Me again: See above indeed.

                                    Me:

                                    All this aside, I should say that I have nothing but the highest regard for the notion of using simulations for analyzing the game of basketball.  To my mind, they are the best method for understanding the effect of marginal changes in game variables.

                                    However, they are not useful - only highly deceptive - in determining the competitiveness of NBA teams from different eras.

                                    no more deceptive than someone stating teams from one era are 10-12 points better than another era without showing the numbers...

                                    Bob:

                                    words from the wise i guess....

                                    Me again:  see above...

                                    i'd love to believe your statements, but you don't show how you arrive at the numbers...


                                    bob chaikin
                                    bchaikin@...

                                  • Dean Oliver <deano@rawbw.com>
                                    Lots to respond to, but one quick thing for now. ... weights hasn t ... other, and ... discernable ... span of ... compared ... impediment to ... So, if I can
                                    Message 17 of 29 , Jan 27, 2003
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                                      Lots to respond to, but one quick thing for now.

                                      --- In APBR_analysis@yahoogroups.com, bchaikin@a... wrote:
                                      > How a simulation should handle different average heights and
                                      weights hasn't
                                      > been answered.
                                      >
                                      > every season NBA teams of varying heights and weights play each
                                      other, and
                                      > that doesn't seem to cause any problems. is there some sort of
                                      discernable
                                      > pattern to equate an advantage or disadvantage statistically in the
                                      span of
                                      > one season such that NBA teams of varying hts and wts cannot be
                                      compared
                                      > directly? if so state it, if not then why should this be an
                                      impediment to
                                      > more than one season of comparisons?...
                                      >

                                      So, if I can show that on average shorter teams do worse than taller
                                      teams and I can show that 1960's teams are on average shorter than
                                      1990's teams, is that reasonable evidence that the 1990's teams are
                                      likely to be better? Is that a fair test?

                                      DeanO
                                    • bchaikin@aol.com
                                      How a simulation should handle different average heights and weights hasn t been answered. every season NBA teams of varying heights and weights play each
                                      Message 18 of 29 , Jan 27, 2003
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                                        How a simulation should handle different average heights and weights hasn't been answered.

                                        every season NBA teams of varying heights and weights play each other, and that doesn't seem to cause any problems. is there some sort of discernable pattern to equate an advantage or disadvantage statistically in the span of one season such that NBA teams of varying hts and wts cannot be compared directly? if so state it, if not then why should this be an impediment to more than one season of comparisons?...

                                        So, if I can show that on average shorter teams do worse than taller teams and I can show that 1960's teams are on average shorter than 1990's teams, is that reasonable evidence that the 1990's teams are likely to be better?  Is that a fair test?

                                        DeanO

                                        did you or did you not pose the statement "...how a simulation should handle the different average hts and wts hasn't been answered..."?

                                        if so, and your next comments are the way you believe to best resolve your own question, then go for it...

                                        i on the other hand do not see any problems whatsoever. every season has tall teams, every season has shorter teams. i can name champonship teams with tall players playing most of the minutes, and ones with players shorter than most of the teams playing the majority of the minutes..

                                        i seem to remember a team winning six titles in the past decade with only one 7 footer, and he played just one season of more than 2000 min in those title years. they had one 6'10" player who for 3 straight titles was 3rd on the team in minutes, behind two players that were 6'6" and 6'7" in height. for their 3 later titles they had one 6'8" guy, and one 6'9" guy coming in off the bench. their 7'2" guy never played as many as 2000 minutes in one of those championship seasons. neither the 6'10" guy in the 1st 3 titles nor the 6''8" guy in the 2nd 3 titles was excessively heavy...

                                        bob chaikin
                                        bchaikin@...







                                      • Dean Oliver <deano@rawbw.com>
                                        ... should handle ... resolve your ... The point was that you seem to claim that height differences don t matter. Compare one season to the next and your
                                        Message 19 of 29 , Jan 27, 2003
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                                          --- In APBR_analysis@yahoogroups.com, bchaikin@a... wrote:
                                          > did you or did you not pose the statement "...how a simulation
                                          should handle
                                          > the different average hts and wts hasn't been answered..."?
                                          >
                                          > if so, and your next comments are the way you believe to best
                                          resolve your
                                          > own question, then go for it...
                                          >

                                          The point was that you seem to claim that height differences don't
                                          matter. Compare one season to the next and your simulator does about
                                          right even though average heights change.

                                          Coaches and scouts certainly use height as a tool for evaluation.
                                          Height helps shoot over people, pass over people, and catch balls.
                                          There is a logical basis for height meaning something.

                                          And there is a statistical basis, too. An inch over the league
                                          average height improves both an offense and a defense.
                                          Statistically, it's true, at least. Not every tall team wins and not
                                          every short team loses. But we're talking statistics, right?

                                          I can give you the numbers, but if you don't think it's true, what's
                                          the point?


                                          >
                                          > i seem to remember a team winning six titles in the past decade
                                          with only one
                                          > 7 footer, and he played just one season of more than 2000 min in
                                          those title
                                          > years. they had one 6'10" player who for 3 straight titles was 3rd
                                          on the
                                          > team in minutes, behind two players that were 6'6" and 6'7" in
                                          height. for
                                          > their 3 later titles they had one 6'8" guy, and one 6'9" guy coming
                                          in off
                                          > the bench. their 7'2" guy never played as many as 2000 minutes in
                                          one of
                                          > those championship seasons. neither the 6'10" guy in the 1st 3
                                          titles nor the
                                          > 6''8" guy in the 2nd 3 titles was excessively heavy...

                                          By the way, those Bulls that you are subtly referring to were not
                                          short. They exceeded the average league height in those years by
                                          playing tall guys at every position but center. Overall, they were
                                          one of the tallest teams each and every one of those 3 years (5th,
                                          8th, and 5th).

                                          DeanO
                                        • bchaikin@aol.com
                                          The point was that you seem to claim that height differences don t matter. Compare one season to the next and your simulator does about right even though
                                          Message 20 of 29 , Jan 28, 2003
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                                            The point was that you seem to claim that height differences don't matter.  Compare one season to the next and your simulator does about right even though average heights change. 

                                            no - i am not claiming anything. it is you claiming/pointing out that the sim does not take into account height differences from year to year, and that it should. my point is the sim does just fine reproducing real life results within a single season where there are players ranging in height anywhere from 5'3" to 7'7" - based on their and their teams real life statistics. statistics in a season are the results of what happened when players of different heights played each other, no? players play multiple seasons, span over not just years but decades...

                                            if one was to truly believe your arguments for why you could not play one season versus another, whether they be close to each other in time or from different eras, simply because the teams don't in real life play each other, then there would never have been a world series in baseball between AL and NL teams when the leagues only played games within their leagues. since the AL only played their AL counterparts, and the NL teams only played their NL counterparts, how could anyone have possibly believed or trusted the result of a match between the AL and NL champions in a world series?? i mean - after all - they never played against one another...this is your logic...

                                            same for ABA teams versus NBA teams. they never played one another during the seasons - how could anyone trust the results between an ABA team and an NBA team, when they have never played each other before? based on your logic they couldn't.....

                                            but i seem to remember alot of world series and ABA/NBA exhibitions...

                                            Coaches and scouts certainly use height as a tool for evaluation.  Height helps shoot over people, pass over people, and catch balls.  There is a logical basis for height meaning something.

                                            height is merely one of a number of facets to a player's game that coaches look at. are you saying height is the only tool coaches/scouts use for evaluation? the major, dominant tool? for every coach you can quote me that says height is a dominant factor, i can quote you one that says speed is more important - for shooting over/thru people, for passing around people, for catching balls. there is a logical basis for speed meaning something also...

                                            And there is a statistical basis, too.  An inch over the league average height improves both an offense and a defense.  Statistically, it's true, at least.  Not every tall team wins and not every short team loses.  But we're talking statistics, right? 

                                            fine, take every team, multiply the players heights (on each of the teams) by their minutes played to get the avg height on the court for each team, and run that thru history by charting it against W-L record, and come up with some kind of correlation factor...

                                            but don't forget to also do this for speed, and dribling ability, and passing ability, and other facets of players......otherwise, based on your logic, you would be leaving out important facets that a sim also does, no?...

                                            I can give you the numbers, but if you don't think it's true, what's the point?

                                            so what if it is true? what is your point? are you suggesting that teams from certain eras need to get a 1 or 2 or some odd point spot in each game played between teams of different eras to account for some statistical height bias? or that rebounding or some other stat should be adjusted because one era is an average of one inch lower than another? what about within the same season?...

                                            what about a statistical bias for speed? are you going to ignore speed but somehow compensate teams for height differences? how can you make some adjustment for height but not speed?...

                                            i could probably do a study that would show that there is a statistical bias between NBA blue eyed players and brown eyed players, as if that really is applicable to the playing of the game, and if there was indeed a statistical bias, such that say brown eyed players scored more (and scoring determines who wins or loses) that some statistical bias should be awarded to teams with more brown eyed players...

                                            when you decide to develop a simulation, if you believe you should award or take away from a team's totals merely because of height differences, or speed differences, or brown/blue eyed differences, be my guest..

                                            if you are going to look at and/or compensate statistically for player height, then you probably should also for player weight, whether a player is R or L handed, whether they are fast or slow, because i'm sure all of these separate facets can be shown to have a statistical bias. how can you pick and choose which to use and which not to use?....

                                            but since players of different heights, different speeds, and different eye color all produce the statistics, i'll just use the actual statistics...

                                            bob chaikin
                                            bchaikin@...









                                          • Dean Oliver <deano@rawbw.com>
                                            One last try. If a team of 6 7 guys wins in a league where the average is 6 5 , would that team do as well in a league where the average is 6 7 ? My sense is
                                            Message 21 of 29 , Jan 28, 2003
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                                              One last try.

                                              If a team of 6'7" guys wins in a league where the average is 6'5",
                                              would that team do as well in a league where the average is 6'7"? My
                                              sense is No. Coaches/scouts say No. The stats say No. Bob says
                                              Yes, it's already accounted for in their basic stats.

                                              Other questions for me to deal with.

                                              --- In APBR_analysis@yahoogroups.com, bchaikin@a... wrote:
                                              > The point was that you seem to claim that height differences don't
                                              matter.
                                              > Compare one season to the next and your simulator does about right
                                              even
                                              > though average heights change.
                                              >
                                              > no - i am not claiming anything. it is you claiming/pointing out
                                              that the sim
                                              > does not take into account height differences from year to year,
                                              and that it
                                              > should. my point is the sim does just fine reproducing real life
                                              results
                                              > within a single season where there are players ranging in height
                                              anywhere
                                              > from 5'3" to 7'7" - based on their and their teams real life
                                              statistics.
                                              > statistics in a season are the results of what happened when
                                              players of
                                              > different heights played each other, no? players play multiple
                                              seasons, span
                                              > over not just years but decades...
                                              >
                                              > if one was to truly believe your arguments for why you could not
                                              play one
                                              > season versus another, whether they be close to each other in time
                                              or from
                                              > different eras, simply because the teams don't in real life play
                                              each other,
                                              > then there would never have been a world series in baseball between
                                              AL and NL
                                              > teams when the leagues only played games within their leagues.
                                              since the AL
                                              > only played their AL counterparts, and the NL teams only played
                                              their NL
                                              > counterparts, how could anyone have possibly believed or trusted
                                              the result
                                              > of a match between the AL and NL champions in a world series?? i
                                              mean - after
                                              > all - they never played against one another...this is your logic...
                                              >
                                              > same for ABA teams versus NBA teams. they never played one another
                                              during the
                                              > seasons - how could anyone trust the results between an ABA team
                                              and an NBA
                                              > team, when they have never played each other before? based on your
                                              logic they
                                              > couldn't.....
                                              >
                                              > but i seem to remember alot of world series and ABA/NBA
                                              exhibitions...
                                              >
                                              > Coaches and scouts certainly use height as a tool for evaluation.
                                              Height
                                              > helps shoot over people, pass over people, and catch balls. There
                                              is a
                                              > logical basis for height meaning something.
                                              >
                                              > height is merely one of a number of facets to a player's game that
                                              coaches
                                              > look at. are you saying height is the only tool coaches/scouts use
                                              for
                                              > evaluation? the major, dominant tool? for every coach you can quote
                                              me that
                                              > says height is a dominant factor, i can quote you one that says
                                              speed is more
                                              > important - for shooting over/thru people, for passing around
                                              people, for
                                              > catching balls. there is a logical basis for speed meaning
                                              something also...
                                              >
                                              > And there is a statistical basis, too. An inch over the league
                                              average
                                              > height improves both an offense and a defense. Statistically, it's
                                              true, at
                                              > least. Not every tall team wins and not every short team loses.
                                              But we're
                                              > talking statistics, right?
                                              >
                                              > fine, take every team, multiply the players heights (on each of the
                                              teams) by
                                              > their minutes played to get the avg height on the court for each
                                              team, and
                                              > run that thru history by charting it against W-L record, and come
                                              up with
                                              > some kind of correlation factor...
                                              >
                                              > but don't forget to also do this for speed, and dribling ability,
                                              and passing
                                              > ability, and other facets of players......otherwise, based on your
                                              logic, you
                                              > would be leaving out important facets that a sim also does, no?...
                                              >
                                              > I can give you the numbers, but if you don't think it's true,
                                              what's the
                                              > point?
                                              >
                                              > so what if it is true? what is your point? are you suggesting that
                                              teams from
                                              > certain eras need to get a 1 or 2 or some odd point spot in each
                                              game played
                                              > between teams of different eras to account for some statistical
                                              height bias?
                                              > or that rebounding or some other stat should be adjusted because
                                              one era is
                                              > an average of one inch lower than another? what about within the
                                              same
                                              > season?...
                                              >
                                              > what about a statistical bias for speed? are you going to ignore
                                              speed but
                                              > somehow compensate teams for height differences? how can you make
                                              some
                                              > adjustment for height but not speed?...
                                              >
                                              > i could probably do a study that would show that there is a
                                              statistical bias
                                              > between NBA blue eyed players and brown eyed players, as if that
                                              really is
                                              > applicable to the playing of the game, and if there was indeed a
                                              statistical
                                              > bias, such that say brown eyed players scored more (and scoring
                                              determines
                                              > who wins or loses) that some statistical bias should be awarded to
                                              teams with
                                              > more brown eyed players...
                                              >
                                              > when you decide to develop a simulation, if you believe you should
                                              award or
                                              > take away from a team's totals merely because of height
                                              differences, or speed
                                              > differences, or brown/blue eyed differences, be my guest..
                                              >
                                              > if you are going to look at and/or compensate statistically for
                                              player
                                              > height, then you probably should also for player weight, whether a
                                              player is
                                              > R or L handed, whether they are fast or slow, because i'm sure all
                                              of these
                                              > separate facets can be shown to have a statistical bias. how can
                                              you pick and
                                              > choose which to use and which not to use?....
                                              >
                                              > but since players of different heights, different speeds, and
                                              different eye
                                              > color all produce the statistics, i'll just use the actual
                                              statistics...
                                              >
                                              > bob chaikin
                                              > bchaikin@b...
                                            • bchaikin@aol.com
                                              One last try. If a team of 6 7 guys wins in a league where the average is 6 5 , would that team do as well in a league where the average is 6 7 ? My sense is
                                              Message 22 of 29 , Jan 28, 2003
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                                                One last try.

                                                If a team of 6'7" guys wins in a league where the average is 6'5", would that team do as well in a league where the average is 6'7"?  My sense is No.  Coaches/scouts say No.  The stats say No.  Bob says Yes, it's already accounted for in their basic stats.

                                                if you are going to pose questions, but then answer your own questions for me yourself, need i be in the discussion?....

                                                i never said yes to this question, so please do not attempt to verify your position by posing questions but then also answering them for me...

                                                we were not talking about a league of 6'7" guys nor 6'5" guys nor any other league other than the NBA (except maybe the ABA), a league where the variation in height changes little from season to season. if you want to do a study of average team height on a year-by-year basis and plot it versus W-L record over time, and present it here as statistical evidence to verify your points for determining some sort of correlation or adjusment factor, go for it. more statistical eveidence is always good. but i'll still look at the NBA stats the players generate and not worry about their height, weight, eye color, or political affiliations...

                                                if a league of 6'7" 150 lb guys with very short arms wins in a league of 6'5" 250 lb guys with very long arms, would that team do as well in a league where everyone else was 6'7" 250 lbs with very long arms? my sense is who cares about any multiple number of factors that can all present their own different statistical bias's? just look at the stats they produce....

                                                bob chaikin
                                                bchaikin@...







                                              • schtevie2003 <schtevie@hotmail.com>
                                                ... Bob: if you tired of the exchange of ideas concerning this discussion, once you have already made your position clear, but do not wish to be bothered to be
                                                Message 23 of 29 , Jan 29, 2003
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                                                  --- In APBR_analysis@yahoogroups.com, bchaikin@a... wrote:

                                                  Bob:

                                                  if you tired of the exchange of ideas concerning this discussion,
                                                  once you have already made your position clear, but do not wish
                                                  to be bothered to be asked to defend your postion with stats in a
                                                  stats analysis group, then maybe this wasn't the forum for you to
                                                  "...add a few pennies worth of thought on the issue of
                                                  inter-temporal comparsions of NBA performance..."...

                                                  Me Now:

                                                  Actually, I don't tire of an exchange of ideas. Not in the least. All
                                                  that I find tiresome is being obliged to repeat myself because
                                                  you do not find it in your interest to respond to vexing arguments.
                                                  And the only idea that has been imparted to me by your
                                                  responses so far is that you have a vested interest in a "sim",
                                                  and you want to use it in completely inappropriate ways, and it
                                                  doesn't really matter what anyone says. Fair enough, I suppose;
                                                  it's your toy, play with it as you will.

                                                  This is not to say that none of your comments could be
                                                  construed to have been offered in good faith. Specifically your
                                                  request for data is perfectly reasonable. And I am happy to
                                                  provide it. See below. But first repeating the punchline...

                                                  *****************


                                                  Me Before:

                                                  the superiority of the average team in the early 80 to its 60s
                                                  counterpart was on the order of 10 to 12 points per game (at a
                                                  modern game pace). This is equivalent to how much better the
                                                  best Bulls team was to the league average.

                                                  Bob:

                                                  not sure what these numbers mean or where they are coming
                                                  from....how did you arrive at this or derive these numbers?...

                                                  ...so let me get this straight, you are saying you have statistically
                                                  come up with a way to show that if the average NBA team of the
                                                  early 1980s (about 109 pts/g) played an average team from the
                                                  1960s (115 pts/g) or early 1960s (almost 116 pts/g), the avg 80s
                                                  team would beat the average 60s team, on average, by 10-12
                                                  points, normalizing for modern times. the 95-96 bulls outscored
                                                  their opponents that year by just over 12 pts/g. so you are saying
                                                  the difference in ability to win of an average early 1980s NBA
                                                  team versus/compared to an average 1960s or early 1960s is
                                                  the same as the 95-96 bulls to the suns or hornets of 95-96
                                                  (.500 teams that year)...

                                                  is this correct?...

                                                  Me Now:

                                                  That is absolutely correct. More precise numbers below.

                                                  ********************


                                                  Me Before:

                                                  The calculation I referred to was made by computing a measure
                                                  of offensive (or equivalently defensive) productivity that I called
                                                  "points per common possession" versus "common
                                                  possessions per game". In the former case, the computation is
                                                  average points scored in the numerator and average common
                                                  possessions in the denominator. Common possessions are,
                                                  by definition and construction, the same for both teams in a
                                                  particular game (hence attractive for purposes of comparison
                                                  and analysis) and are basically calculated by subtracting the
                                                  number of offensive rebounds from the conventionally defined
                                                  number of possessions a team enjoys in a game.

                                                  Bob:

                                                  fine...so fill in the blanks below so we can compare...or show us
                                                  your numbers that show how you arrived at your result...

                                                  pts/ sec/ pts/
                                                  year FG% g poss poss
                                                  5960 .410 115.3
                                                  6061 .415 118.1
                                                  6162 .426 118.8
                                                  6263 .441 115.3
                                                  6364 .433 111.0
                                                  6465 .426 110.6
                                                  6566 .433 115.5
                                                  6667 .441 117.4
                                                  6768 .446 116.6
                                                  6869 .441 112.3
                                                  6970 .460 116.7
                                                  7071 .449 112.4
                                                  7172 .455 110.2
                                                  7273 .456 107.6
                                                  7374 .459 105.7
                                                  7475 .457 102.3
                                                  7576 .458 104.3
                                                  7677 .465 106.5

                                                  pts/
                                                  48min
                                                  7778 .469 107.7 13.4 1.000
                                                  7879 .485 109.8 13.5 1.029
                                                  7980 .481 108.5 13.8 1.041
                                                  8081 .486 107.5 14.0 1.043
                                                  8182 .491 107.9 14.1 1.058
                                                  8283 .485 107.9 13.8 1.037
                                                  8384 .492 109.2 14.0 1.063
                                                  8485 .491 110.2 13.9 1.066
                                                  8586 .487 109.5 13.9 1.059
                                                  8687 .480 109.2 14.1 1.067
                                                  8788 .480 107.6 14.3 1.065
                                                  8889 .477 108.5 14.1 1.062
                                                  8990 .476 106.3 14.4 1.065
                                                  9091 .474 105.5 14.5 1.063
                                                  9192 .472 104.5 14.7 1.067
                                                  9293 .473 104.5 14.7 1.066
                                                  9394 .466 101.0 15.0 1.049
                                                  9495 .466 100.6 15.3 1.069
                                                  9596 .462 98.8 15.5 1.063
                                                  9697 .455 96.2 15.8 1.053
                                                  9798 .450 94.8 15.7 1.036
                                                  9899 .437 90.9 16.0 1.009
                                                  9900 .449 96.9 15.3 1.030
                                                  0001 .443 94.0 15.6 1.020
                                                  0102 .445 94.8 15.7 1.034

                                                  DeanO has pointed out that "...this trend looks about right, even if
                                                  my calculations have slight differences...". so if we are defining
                                                  offensive productivity as pts/poss, i see similar pts/poss
                                                  numbers with varying FG% and pts/g and game pace for 77-78
                                                  thru today. if your number show a different trend for prior to
                                                  77-78, lets see them...

                                                  Me Now:

                                                  Well, here are my numbers. They summarize the yearly average
                                                  team performance in the league. There are four columns. The
                                                  year refers to the end year of the season. "CP/game" is
                                                  "Common Possessions per Game". "P/CP" is "Points per
                                                  Common Possession". "P*/CP is the same stat except the
                                                  points are modified to subtract out the third point of completed
                                                  three pointers. Finally, "3pt effect" differences the two previous
                                                  columns.

                                                  Year CP/game P/CP P*/CP 3pt effect
                                                  57 116.4 .856 .856
                                                  58 124.7 .855 .855
                                                  59 124.5 .870 .870
                                                  60 131.2 .879 .879
                                                  61 132.9 .889 .889
                                                  62 131.4 .904 .904
                                                  63 124.5 .926 .926
                                                  64 121.5 .913 .913
                                                  65 122.4 .904 .904
                                                  66 126.1 .916 .916
                                                  67 126.6 .927 .927
                                                  68 124.8 .934 .934
                                                  69 121.7 .923 .923
                                                  70 122.0 .957 .957
                                                  71 119.7 .939 .939
                                                  72 116.4 .946 .946
                                                  73 114.7 .938 .938
                                                  74 111.7 .946 .946
                                                  75 108.5 .946 .946
                                                  76 109.6 .952 .952
                                                  77 110.5 .964 .964
                                                  78 111.0 .977 .977
                                                  79 109.7 1.005 1.005
                                                  80 107.3 1.019 1.012 .007
                                                  81 105.9 1.021 1.016 .005
                                                  82 104.7 1.037 1.031 .006
                                                  83 107.0 1.015 1.010 .005
                                                  84 105.7 1.042 1.036 .006
                                                  85 106.1 1.045 1.036 .008
                                                  86 106.2 1.038 1.029 .009
                                                  87 105.0 1.047 1.034 .014
                                                  88 103.5 1.045 1.030 .015
                                                  89 104.9 1.041 1.021 .020
                                                  90 102.4 1.045 1.024 .021
                                                  91 102.0 1.043 1.020 .022
                                                  92 100.7 1.046 1.021 .025
                                                  93 100.7 1.045 1.015 .030
                                                  94 98.7 1.028 .995 .033
                                                  95 96.8 1.048 .991 .057*
                                                  96 95.5 1.042 .980 .062*
                                                  97 93.9 1.032 .967 .064*
                                                  98 94.2 1.015 .968 .047
                                                  99 92.7 .987 .939 .048
                                                  00 96.7 1.008 .957 .050
                                                  01 95.1 .997 .946 .051
                                                  02 94.4 1.011 .956 .055

                                                  Now before discussing trends and repeating the arguments, let
                                                  me lay out the sources and methods behind these statistics.

                                                  All data for the "NBA average" are from the Official NBA Guide.
                                                  "CP/game" is the following sum of terms (divided by games
                                                  played): Field Goal Attempts + 0.45 * Free Throw Attempts + 1.05
                                                  * Turnovers - 1.045 * Offensive Rebounds. What this statistic
                                                  represents again are the number of common possessions
                                                  between a team and its opponent, or alternatively expressed, the
                                                  number of continuous possessions - continuous meaning no
                                                  additional possession is counted on an offensive rebound. Why
                                                  the various factors. Possessions are disposed of as (1) field
                                                  goal attempts, (2) two shot free throw attempts (three shot free
                                                  throws are ignored) which I estimate as one half of 90% of all
                                                  attempts (the other 10% being technicals and attempts after
                                                  made shots) hence 0.45, (3) turnovers, where a 5% estimate of
                                                  team turnovers is added, and (4) offensive rebounds, where
                                                  4.5% is the estimate of team offensive rebounds. It should be
                                                  noted that none of the results are sensitive to the factors chosen
                                                  which is obvious as the last two terms effectively cancel
                                                  eachother out.

                                                  For the missing turnover and offensive rebound series prior to
                                                  1974, I extrapolated using 1974 data. Specifically, for offensive
                                                  rebounds, I calculated an offensive rebounding percentage for
                                                  missed field goal attempts of 28.7 (and assumed a constant 5%
                                                  value for offensive rebounds of missed final free throws). This
                                                  should not be a controversial value as the percentage hovers
                                                  quite closely about 30%. And for the turnover series, I assumed
                                                  a stable relationship of turnovers to field goal attempts and two
                                                  point field goal attempts, and this value in 1974 was 0.198. In
                                                  this case, given the downward trend over time in turnover rate,
                                                  this value is almost certainly biased low which would have the
                                                  effect on the data of biasing CP/game down and P/CP up - that is
                                                  to say exaccerbating the trends I identify.

                                                  On to the analysis...

                                                  What are the apparent trends. Well, I don't think there is any
                                                  ambiguity on the point that the CP/game series trends
                                                  downward over time. Given that I started off recalling data over
                                                  the 60s and 70s, let me take '60 and '79 as endpoints to begin
                                                  the discussion. Note a drop in game pace from 131.2 to 109.7
                                                  possessions per game, a decrease of 15.6%. And during which
                                                  time offensive productivity increased 11% (.879 to 1.005). Put
                                                  another way, the average team in 1979, playing at its slower
                                                  pace would be expected to beat the average team of 1960 by
                                                  13.82 points per game (.126 P/CP * 109.7 CP/game).

                                                  And how can this be said to be true? To repeat the argument
                                                  that hasn't been adressed: slowing the pace of the game, all
                                                  else equal, is only compatible theoretically with decreased
                                                  offensive productivity. That there was an increase in offensive
                                                  productivity must then mean that there was improvement in the
                                                  way the game was played offensively. This didn't mean that the
                                                  '79 players were supermen (though they may have been better
                                                  athletes). It means that the offensive "technology" improved.
                                                  And what were its intermediate effects: lower turnover rates
                                                  (identified after '73) and higher field goal percentages (apparent
                                                  throughout). It also doesn't rule the possibility that defenses
                                                  improved also, just that on net there was a huge gain for the
                                                  offenses.

                                                  Now, Bob, if you can find another explanation for these offsetting
                                                  trends, and frankly you must if you expect any serious
                                                  consideration of results from "unadjusted" cross-generational
                                                  simulations, please provide it. There may be one; I just haven't
                                                  been able to come up with it over the years. Please try.

                                                  As for the longer-term trends, picking up from the late seventies,
                                                  the trends should be clear. The pace of the game continues to
                                                  fall, and offensive productivity rises and plateaus for a few years
                                                  in the middle 80s, then begins a "mild" decline (that if you hold
                                                  the view that losing about four points per game is mild - roughly
                                                  equivalent to home court advantage or, alternatively, half the way
                                                  from mediocrity to championship status, as I noted before) or
                                                  alternatively a very significant decline depending on your
                                                  perspective.

                                                  To understand this "dilemna" see the last two columns. They
                                                  explain the contribution of the three point shot to maintaining
                                                  "nominal" productivity. For example, in '02 three point shots
                                                  raised the P/CP by 0.055 (or rougly 5 points per game). How
                                                  P*/CP should be interpreted then is as a kind of low estimate of
                                                  productivity. Clearly if teams would only be getting two points for
                                                  a shot behind the three point line, they wouldn't take as many
                                                  and would instead opt more for more mid-range jumpers.
                                                  However, the low estimate might not be that far off. Consider
                                                  that in '95 through '97 the three point distance was moved in to
                                                  not much effect.

                                                  Whatever the case, the essential is this. From the mid to late
                                                  80's on, offensive productivity has trended downwards along with
                                                  the pace of the game. In this environment, one could infer that
                                                  either offenses were getting worse or that defenses were getting
                                                  better. And my view is already on record. The argument again: if
                                                  you have a quarter century of relentless net offensive progress
                                                  (and almost certainly some counterveiling defensive progress
                                                  as well) it seems absurd to argue that come the mid-80's
                                                  progress came to a screeching halt and was followed by 15 to
                                                  20 years of, yes, technological retrogression.

                                                  So there is the evidence....gotta run...enjoy your dinner.
                                                • bchaikin@aol.com
                                                  Bob: if you tired of the exchange of ideas concerning this discussion, once you have already made your position clear, but do not wish to be bothered to be
                                                  Message 24 of 29 , Jan 29, 2003
                                                  • 0 Attachment

                                                    Bob:

                                                    if you tired of the exchange of ideas concerning this discussion, once you have already made your position clear, but do not wish to be bothered to be asked to defend your postion with stats in a stats analysis group, then maybe this wasn't the forum for you to "...add a few pennies worth of thought on the issue of inter-temporal comparsions of NBA performance..."...

                                                    Me Now:

                                                    Actually, I don't tire of an exchange of ideas.  Not in the least.  All that I find tiresome is being obliged to repeat myself

                                                    no one has yet asked you to repeat yourself, on the contrary if you re-read responses to your postings you have simply been asked a number of times to clarify your statements with numbers (again as this is a stats analysis group) - i.e. show the stats to back up your statements. up and to this last posting you hadn't done that, despite making statements and brandishing them as fact...

                                                    because you do not find it in your interest to respond to vexing arguments.

                                                    not in my interest? now that you've finally shown your stats to supposedly back up your statements its going to be fun poking holes in your apparently flawless logic...

                                                    And the only idea that has been imparted to me by your responses so far is that you have a vested interest in a "sim",

                                                    then maybe you should show some initiative on your part and read the postings pertinent to this cross-generational discussion that occurred prior to your first posting of 1/2/03. this all started back on 12/10/02 in message 1552 under a topic called "talent dilution". in message 1561 on the same topic the question was raised "....if (only) we could run simulations...on these questions..." of playing teams of different eras against one another....."....

                                                    but before the topic of even the viability of a simulation was even considered the very next message (1562) contained the statement "...cross-generational team comparisons are subject to so many what-ifs that no one trusts them....". now its fine to state that a sim is subject to "...so many what-ifs...." as that is something we can discuss/debate in a stats analysis group - that's what this group is all about isn't it? after all a simulation is nothing more than an extension of statistical analysis to model a real-life process, similar to modeling the building of widgets in a factory setting or launching a probe into space or any other process that can be quantified...

                                                    but for someone to blatantly state that "...no one trusts them...", as if that statement had any merit whatsoever (such as did this person review a number of basketball simulations and found them to be lacking, and then discussed this with a number of others who had done just that, or attempted to create a simulation and found it fraught with inconsistencies), reaks of ignorance. if someone was to state that this group member's individual basketball research was totally without merit (or anyone's research for that fact), or that "...no one would trust it...", without that someone even having reviewed that person's research, that too would show ignorance...

                                                    and you want to use it in completely inappropriate ways,

                                                    this is your opinion? that to use a computer simulation to model a real-life process is inappropriate? and then to extend that model to go beyond what is actually done in real life to model even more? my now aren't you the researcher........

                                                    fyi pretty much every process in the real world today, from the fields of sports to medicine to physics to space to whatever, especially in state-of-the-art endeavors, develops computer models based on real world scenarios and then extrapolates those scenarios for predictive purposes, such that further research has a definitive path to follow rather than a blind path.....

                                                    and it doesn't really matter what anyone says.....

                                                    once again, on the contrary. what you say does matter, that is why i and others are responding to your postings - but do you expect us to simply take your word for your supposedly factual statements? again this is a stats analysis group and you are just now backing up your statements with some statistical evidence...

                                                    and i've noticed a tendency in this discussion group for a small minority of the people to make statements and claim them as fact, but when they don't - or can't - back up their statements with some sort of accompanying statistical evidence, they resort to using words like "...absurdly obvious..." to emphasize their point, or make statements like "....it appears that the dead equine will receive another whuppin'...", as if this verification for their opinions....

                                                    Fair enough, I suppose; it's your toy, play with it as you will.

                                                    at least i will be looking at your data first - prior to commenting one way or the other on it......i've been asking to see it a number of times....

                                                    This is not to say that none of your comments could be construed to have been offered in good faith.  Specifically your request for data is perfectly reasonable.  And I am happy to provide it.  See below.  But first repeating the punchline...

                                                    Me Before:

                                                    the superiority of the average team in the early 80 to its 60s counterpart  was on the order of 10 to 12 points per game (at a modern game pace).  This is equivalent to how much better the best Bulls team was to the league average.

                                                    Bob:

                                                    not sure what these numbers mean or where they are coming from....how did you  arrive at this or derive these numbers?...

                                                    ...so let me get this straight, you are saying you have statistically come up with a way to show that if the average NBA team of the early 1980s (about 109 pts/g) played an average team from the 1960s (115 pts/g) or early 1960s (almost 116 pts/g), the avg 80s team would beat the average 60s team, on average, by 10-12 points, normalizing for modern times. the 95-96 bulls outscored their opponents that year by just over 12 pts/g. so you are saying the difference in ability to win of an average early 1980s NBA team versus/compared to an average 1960s or early 1960s is the same as the 95-96 bulls to the suns or hornets of 95-96 (.500 teams that year)...

                                                    is this correct?...

                                                    Me Now:

                                                    That is absolutely correct.  More precise numbers below.

                                                    Me Before:

                                                    The calculation I referred to was made by computing a measure of offensive (or equivalently defensive) productivity that I called "points per common possession" versus "common possessions per game".  In the former case, the computation is
                                                    average points scored in the numerator and average common possessions in the denominator.  Common possessions are, by definition and construction, the same for both teams in a particular game (hence attractive for purposes of comparison
                                                    and analysis) and are basically calculated by subtracting the number of offensive rebounds from the conventionally defined number of possessions a team enjoys in a game.

                                                    Bob:

                                                    fine...so fill in the blanks below so we can compare...or show us your numbers that show how you arrived at your result...

                                                                              pts/      sec/      pts/
                                                    year      FG%      g          poss     poss
                                                    5960      .410     115.3
                                                    6061      .415     118.1
                                                    6162      .426     118.8
                                                    6263      .441     115.3
                                                    6364      .433     111.0
                                                    6465      .426     110.6
                                                    6566      .433     115.5
                                                    6667      .441     117.4
                                                    6768      .446     116.6
                                                    6869      .441     112.3
                                                    6970      .460     116.7
                                                    7071      .449     112.4
                                                    7172      .455     110.2
                                                    7273      .456     107.6
                                                    7374      .459     105.7
                                                    7475      .457     102.3
                                                    7576      .458     104.3
                                                    7677      .465     106.5

                                                                              pts/      sec/      pts/
                                                                  FG%   48min   poss      poss
                                                    7778      .469     107.7    13.4      1.000
                                                    7879      .485     109.8    13.5      1.029
                                                    7980      .481     108.5    13.8      1.041   
                                                    8081      .486     107.5    14.0      1.043
                                                    8182      .491     107.9    14.1      1.058
                                                    8283      .485     107.9    13.8      1.037
                                                    8384      .492     109.2    14.0      1.063
                                                    8485      .491     110.2    13.9      1.066
                                                    8586      .487     109.5    13.9      1.059
                                                    8687      .480     109.2    14.1      1.067
                                                    8788      .480     107.6    14.3      1.065
                                                    8889      .477     108.5    14.1      1.062
                                                    8990      .476     106.3    14.4      1.065
                                                    9091      .474     105.5    14.5      1.063
                                                    9192      .472     104.5    14.7      1.067
                                                    9293      .473     104.5    14.7      1.066
                                                    9394      .466     101.0    15.0      1.049
                                                    9495      .466     100.6    15.3      1.069
                                                    9596      .462      98.8     15.5      1.063
                                                    9697      .455      96.2     15.8      1.053
                                                    9798      .450      94.8     15.7      1.036
                                                    9899      .437      90.9     16.0      1.009
                                                    9900      .449      96.9     15.3      1.030
                                                    0001      .443      94.0     15.6      1.020
                                                    0102      .445      94.8     15.7      1.034

                                                    DeanO has pointed out that "...this trend looks about right, even if my calculations have slight differences...". so if we are defining offensive productivity as pts/poss, i see similar pts/poss numbers with varying FG% and pts/g and game pace for 77-78
                                                    thru today. if your number show a different trend for prior to 77-78, lets see them...

                                                    Me Now:

                                                    Well, here are my numbers.  They summarize the yearly average team performance in the league.  There are four columns.  The year refers to the end year of the season.  "CP/game" is "Common Possessions per Game".  "P/CP" is "Points per
                                                    Common Possession".  "P*/CP is the same stat except the points are modified to subtract out the third point of completed three pointers.  Finally, "3pt effect" differences the two previous columns.

                                                    Year  CP/game  P/CP  P*/CP  3pt effect
                                                    57      116.4        .856     .856
                                                    58      124.7        .855     .855
                                                    59      124.5        .870     .870
                                                    60      131.2        .879     .879
                                                    61      132.9        .889     .889
                                                    62      131.4        .904     .904
                                                    63      124.5        .926     .926
                                                    64      121.5        .913     .913
                                                    65      122.4        .904     .904
                                                    66      126.1        .916     .916
                                                    67      126.6        .927     .927
                                                    68      124.8        .934     .934
                                                    69      121.7        .923     .923
                                                    70      122.0        .957     .957
                                                    71      119.7        .939     .939
                                                    72      116.4        .946     .946
                                                    73      114.7        .938     .938
                                                    74      111.7        .946     .946
                                                    75      108.5        .946     .946
                                                    76      109.6        .952     .952
                                                    77      110.5        .964     .964
                                                    78      111.0        .977     .977
                                                    79      109.7      1.005   1.005
                                                    80      107.3      1.019   1.012   .007 
                                                    81      105.9      1.021   1.016   .005
                                                    82      104.7      1.037   1.031   .006
                                                    83      107.0      1.015   1.010   .005
                                                    84      105.7      1.042   1.036   .006
                                                    85      106.1      1.045   1.036   .008
                                                    86      106.2      1.038   1.029   .009
                                                    87      105.0      1.047   1.034   .014
                                                    88      103.5      1.045   1.030   .015
                                                    89      104.9      1.041   1.021   .020
                                                    90      102.4      1.045   1.024   .021
                                                    91      102.0      1.043   1.020   .022
                                                    92      100.7      1.046   1.021   .025
                                                    93      100.7      1.045   1.015   .030
                                                    94        98.7      1.028     .995    .033
                                                    95        96.8      1.048     .991    .057*
                                                    96        95.5      1.042     .980    .062*
                                                    97        93.9      1.032     .967    .064*
                                                    98        94.2      1.015     .968    .047
                                                    99        92.7        .987     .939    .048
                                                    00       96.7      1.008     .957    .050
                                                    01        95.1        .997     .946    .051
                                                    02        94.4      1.011     .956    .055

                                                    Now before discussing trends and repeating the arguments, let me lay out the sources and methods behind these statistics.

                                                    All data for the "NBA average" are from the Official NBA Guide.  "CP/game" is the following sum of terms (divided by games played): Field Goal Attempts + 0.45 * Free Throw Attempts + 1.05 * Turnovers - 1.045 * Offensive Rebounds.  What this statistic represents again are the number of common possessions between a team and its opponent, or alternatively expressed, the number of continuous possessions - continuous meaning no additional possession is counted on an offensive rebound.  Why the various factors.  Possessions are disposed of as (1) field goal attempts, (2) two shot free throw attempts (three shot free throws are ignored) which I estimate as one half of 90% of all attempts (the other 10% being technicals and attempts after
                                                    made shots) hence 0.45, (3) turnovers, where a 5% estimate of team turnovers is added, and (4) offensive rebounds, where 4.5% is the estimate of team offensive rebounds.  It should be noted that none of the results are sensitive to the factors chosen which is obvious as the last two terms effectively cancel eachother out.

                                                    at least for 77-78 thru today, our numbers match fairly closely, and the trends even closer. obviously we are calculating things quite similarly. for benefit of the doubt i'll assume your pre-77-78 estimates are valid for calculating possessions and pts/poss...

                                                    For the missing turnover and offensive rebound series prior to 1974, I extrapolated using 1974 data.  Specifically, for offensive rebounds, I calculated an offensive rebounding percentage for missed field goal attempts of 28.7 (and assumed a constant 5% value for offensive rebounds of missed final free throws).  This should not be a controversial value as the percentage hovers quite closely about 30%.  And for the turnover series, I assumed a stable relationship of turnovers to field goal attempts and two point field goal attempts, and this value in 1974 was 0.198.  In this case, given the downward trend over time in turnover rate, this value is almost certainly biased low which would have the effect on the data of biasing CP/game down and P/CP up - that is to say exaccerbating the trends I identify.

                                                    On to the analysis...

                                                    What are the apparent trends.  Well, I don't think there is any ambiguity on the point that the CP/game series trends downward over time. 

                                                    agreed....

                                                    Given that I started off recalling data over the 60s and 70s, let me take '60 and '79 as endpoints to begin the discussion.  Note a drop in game pace from 131.2 to 109.7 possessions per game, a decrease of 15.6%.  And during which time offensive productivity increased 11% (.879 to 1.005).  Put another way, the average team in 1979, playing at its slower pace would be expected to beat the average team of 1960 by 13.82 points per game (.126 P/CP * 109.7 CP/game).

                                                    so this is your magical brain storm as to why an average 1978-79 team is almost 14 points better than an average 1959-60 team??? you're blatantly stating, based on this one lonely calculation, that:

                                                    "....the superiority of the average team in the early 80 (in this case 1978-79) to its 60s counterpart was on the order of 10 to 12 points per game (at a modern game pace). This is equivalent to how much better the best Bulls team was to the league average....."

                                                    you're saying that based on this calculation alone that if the 43-39 san diego clippers or the 38-44 golden state warriors of 1978-79 (closest to avg teams in 78-79) would decimate all of the average teams from 1959-60 by almost 14 pts/g if they played in that year? 14 pts/g on average? 5 of the 8 teams that year only outscored their opponents by +-3 pts/g all year, so thats close to average, so they'd consistently beat these teams like the 72-10 bulls beat an avg team in 1995-96? and teams better than these clippers and warriors would, by virtue of being better than them, beat the 59-60s teams by an even worse margin of average victory?...

                                                    lets look at this even closer...

                                                    your numbers also show the offensive productivity of pts/poss in 1966-67 is 0.927, and in 1979-80 is 1.019. so based on these numbers, at a modern pace (in 79-80 of 107.3 CP/game), that offensive productivity increased from 0.927 to 1.019 (difference of 9%), and 0.090 P/CP * 107.3 CP/game is 9.7 pts. so you are saying that an average team from 1979-80 (like the 41-41 houston rockets and 41-41 san antonio spurs) would outscore - on average each game - an average 1966-67 team (cincinnati royals or st louis hawks, both 39-42) by almost 10 pts each game - on average? plus the teams better than the rockets and spurs would beat them - on average - by upwards of 10 or 11 points, and those much better than the rockets and spurs by even 12 or more points per game?....

                                                    well in 1966-67 the philadelphia 76ers of wilt chamberlain and company only outscored the rest of the league by 9.4 pts/g. you're saying that these .500 teams of 79-80 are 9.7 pts/g better than an average team in 66-67, which would put them on par with the 1966-67 76ers, even slightly better, of wilt chamberlain, luke jackson, hal greer, chet walker, wali jones, and billy cunningham, a team that many would argue is one of the absolute best if not the best teams ever assembled in the history of the NBA, and a team only 13 years earlier in time from 79-80. and not only are you saying that these average teams are slightly better, but that every team in 1979-80 that was above .500, another 9 teams, were thus also better (ostensibly much better) than the 1966-67 philadelphia 76ers?....

                                                    that would also mean that - based on this one single magical calculation - that in the span of maybe a 5 year period of the late 70s and early 80 (77-78 to 81-82) there'd easily be another 15-20 teams statistically better than the 66-67 76ers (3-4 if not more top teams in the league for each year, well above .500 average teams), one of the greatest teams many would argue that was ever assembled....

                                                    does anyone in their right mind think that an average team from 79-80 was as good as the 66-67 76ers, and a whole host of teams slightly better than average from 77-78 thru 81-82?? people today debate games between the great celtic teams and great lakers team of the 80s and bulls teams of the 90s against the 66-67 76ers, and you're magical calculation stating its simply no contest?...

                                                    that would mean that based on your method of determing how much better teams are over eras, that since your pts/poss numbers are even higher after 79-80 (into the decade of the 1980s), that a whole slew of teams, maybe even the vast majority that played over .500 ball in the 1980s, would consistently beat the 66-67 philadelphia 76ers, one of the greatest teams ever, because that magical point difference you concocted would be even greater than 9.7 pts/g because all thru the 1980s the pts/poss was much greater than 1.019, but upwards of 1.030-1.040...

                                                    and let's take this even a step further.....in 1994-95 the avg pts/poss - based on your numbers - was 1.048, in 98-99 it was 0.987. that's a difference of 0.061. at a CP/game of 92.7 for 98-99 thats .061 * 92.7 = 5.7 point difference, such that based on your magical calculation it shows that based on these calculations of offensive productivity that the average team in 94-95 would beat the average team in 98-99 by 5.7 points, on average, leagues only five years apart! this is the identical calculation method that you have used to show a 78-79 average team was almost 14 points better than an average 59-60 team. if this magical calculation works backwards in time, it must work forward in time, and since offensive productivity shows no trend with game pace in the 1980s and 1990s, so based on your method the average team in 94-95 is only slightly worse than the 2nd and 3rd best teams of 98-99 (utah and portland) who only outscored their opponents by 6.5 and 6.4 pts/g, that in the span of just 5 years, when many players played in both seasons, all of a sudden the league was much worse!...

                                                    you state that P/CP or pts/poss is an indication of offensive productivity. i agree as it is points scored normalized to a single team possession - it takes game pace out of the equation for determining offensive productivity. our methods of determining this pts/poss are obviously similar, as well as DeanO's, and while yours may show an increase in pts/poss from the early 60s to the late 70s based on estimated values for unknown parameters while game pace consistently decreased, there is absolutely no trend like this from 1978-79 to today. the numbers - your numbers in fact - show this....

                                                    your numbers show pts/poss of 1.005 in 78-79, and a similar 1.015 (a one percent difference in the two) in 97-98, a time span of a full 20 years! absolutely no difference!  but game pace has decreased from 109.7 CP/game to 94.2 in that same time span, a difference a full 14 % slower game pace - absolutely no trend whatsoever that offensive productivity follows game pace. so while your data may show a trend from the early 60s to the late 70s (with some parameters estimated), it show no trend here. and for you to state that this evidence shows an increase offensive productivity with an increase with game pace, it shows nothing whatsoever over the last 23+ years...

                                                    pts/poss numbers from 78-79 to 97-98, a 20 year time span, show a range in pts/poss of 1.005-1.048, a difference of 4%. and that varies throughout the 20 year sequence - no trend. even if you look at your 'adjusted" P*/CP from 78-79 to 92-93, the variation is only from 1.005 to 1.036, a variation of just 3 percent while game pace dropped from 109.7 CP/game to 100.7, a difference of an over 8% slower game - thus no trend of game pace at all with pts/poss...

                                                    And how can this be said to be true?  To repeat the argument that hasn't been addressed: slowing the pace of the game, all else equal, is only compatible theoretically with decreased offensive productivity. 

                                                    absolute nonsense.......not only has it been addressd, but also debunked.......on the contrary there is no trend whatsoever.....your conclusion/statement is not backed up by your stats.....

                                                    That there was an increase in offensive productivity must then mean that there was improvement in the way the game was played offensively. 

                                                    certainly not....offense could have stayed the same and defense weakened to adjust offense upward.......the pts/poss are not absolute numbers like breaking the time of a 100 yard dash but relative numbers of offense versus defense.....the numbers vary not because of some human extreme being reached - again a conclusion not backed up by your stats, but as a variation of a similar process......again one can easily, and i repeat easily, say the defense got worse so as to bring the level of offense up, and the number pts/poss is defined by offense versus defense, not like FT% which is a player versus the basket and not another player...

                                                    This didn't mean that the '79 players were supermen (though they may have been better athletes).  It means that the offensive "technology" improved. 

                                                    then based on this convoluted logic the game of 1998-99 (pts/poss of .987) was only being played at the level of 1977-78 (pts/poss 0.977) with seasons like 86-87 (pts/poss of 1.047) and 1994-95 (pts/poss of 1.048) has average teams that could easily beat most teams from 77-78 and 98-99 because of your magical calculation......

                                                    this reasoning is absolutely porous. the variation of pts/poss is simply a variation of a similar process with the differences being the years being slight. no way are the teams of the mid 1980s 5-6 pts/g better than the late 70s or late 90s.....and your magical calculation has no basis in fact....

                                                    And what were its intermediate effects: lower turnover rates identified after '73)
                                                    and higher field goal percentages (apparent throughout).  It also doesn't rule the possibility that defenses improved also, just that on net there was a huge gain for the offenses.

                                                    Now, Bob, if you can find another explanation for these offsetting trends,

                                                    no trend whatsoever between pts/poss and game pace (CP/game) after 77-78...

                                                    and frankly you must if you expect any serious consideration of results from "unadjusted" cross-generational simulations, please provide it.

                                                    after seeing your "serious" adjustment factor for how much better average teams are from one year to another, i'll stick with unadjusted.....your magical adjustment factor that places average teams from the late 70s and early 80s on par with the great 66-67 76ers and that states that slightly better than average teams from that same time period are actually better teams than the 66-67 76ers tells me just about all i need to know about your methods...

                                                    There may be one; I just haven't been able to come up with it over the years.  Please try.

                                                    1966-67 phuladelphia 76ers, 1966-67 philadelphia 76ers, 1966-67 philadelphia 76ers......this is kinda like another posting in this discussion group about different player ratings of sportswriters that did not show shaquille o'neal to be one of the best if not the very best player in the league, and also had andrei kirilenko of the jazz rated 2nd or 3rd best. seeing that told all you needed to know about the rating system...

                                                    As for the longer-term trends, picking up from the late seventies, the trends should be clear.  The pace of the game continues to fall,

                                                    yes....

                                                    and offensive productivity rises and plateaus for a few years in the middle 80s,

                                                    huh? for a few years? who you kidding? the offensive productivity does not continue to fall, even as game pace does. the offesnive prodictivity numbers (pys/poss) of 97-98 thru 01-02 are simlar to the late 70s and before, but from the early 80s to mid to late 90s the pts/poss numbers vary from a low of 1.015 to 1.048, a difference of just a measly 3%, with no discernible pattern - just fluctuation, which the game pace showing a definite pattern of decreasing.....your number and my numbers both show this....

                                                    then begins a "mild" decline (that if you hold the view that losing about four points per game is mild - roughly equivalent to home court advantage or, alternatively, half the way from mediocrity to championship status, as I noted before) or alternatively a very significant decline depending on your perspective.

                                                    To understand this "dilemna" see the last two columns.  They explain the contribution of the three point shot to maintaining "nominal" productivity.  For example, in '02 three point shots raised the P/CP by 0.055 (or rougly 5 points per game). How P*/CP should be interpreted then is as a kind of low estimate of productivity.  Clearly if teams would only be getting two points for a shot behind the three point line, they wouldn't take as many and would instead opt more for more mid-range jumpers. 

                                                    and shot a higher percentage from 2pt range. pts/poss are pts/poss, the avg FG% for 2pters since 79-80 is .488 (close to .500) and for 3pters is .339 (close to.333). so if players did not take 3pters based on your logic they would be scoring just as much taking 2pters based on the statistical evidence...

                                                    However, the low estimate might not be that far off.  Consider that in '95 through '97 the three point distance was moved in to not much effect.

                                                    Whatever the case, the essential is this.  From the mid to late 80's on, offensive productivity has trended downwards along with the pace of the game. 

                                                    nope....not at all...overall pts/poss varied but remained close to 1.041 - 1.047 in the mid to late 1980s.......

                                                    In this environment, one could infer that either offenses were getting worse or that defenses were getting better.  And my view is already on record.  The argument again: if you have a quarter century of relentless net offensive progress (and almost certainly some counterveiling defensive progress as well) it seems absurd to argue that come the mid-80's progress came to a screeching halt and was followed by 15 to
                                                    20 years of, yes, technological retrogression.

                                                    while our stats are similar, your logic is quite flawed, as is your method for equating teams from different eras...

                                                    So there is the evidence....gotta run...enjoy your dinner.

                                                    bob chaikin
                                                    bchaikin@...


                                                  • Dean Oliver <deano@rawbw.com>
                                                    ... philadelphia ... group about ... shaquille o neal ... and also had ... told all you ... Actually, that wasn t a sportswriter rating. That was Jeff
                                                    Message 25 of 29 , Jan 30, 2003
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                                                      --- In APBR_analysis@yahoogroups.com, bchaikin@a... wrote:
                                                      > 1966-67 phuladelphia 76ers, 1966-67 philadelphia 76ers, 1966-67
                                                      philadelphia
                                                      > 76ers......this is kinda like another posting in this discussion
                                                      group about
                                                      > different player ratings of sportswriters that did not show
                                                      shaquille o'neal
                                                      > to be one of the best if not the very best player in the league,
                                                      and also had
                                                      > andrei kirilenko of the jazz rated 2nd or 3rd best. seeing that
                                                      told all you
                                                      > needed to know about the rating system...

                                                      Actually, that wasn't a sportswriter rating. That was Jeff Sagarin's
                                                      mathematical method (along with Wayne Winston, a business prof). The
                                                      method is pretty good, looking at how well different combinations of
                                                      players do, who they play against, then isolating each player's
                                                      contribution, but the results are highly suspect and I continue to
                                                      wonder why. I think I understand but it's complex.

                                                      Sagarin does have a public email that I just found. I'd be curious
                                                      to ask him about it...

                                                      DeanO
                                                    • schtevie2003 <schtevie@hotmail.com>
                                                      Bob, I am heartened that at long last you are finally beginning to understand the empirical history involved (though for some reason the 80s to present still
                                                      Message 26 of 29 , Jan 30, 2003
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                                                        Bob,

                                                        I am heartened that at long last you are finally beginning to
                                                        understand the empirical history involved (though for some
                                                        reason the 80s to present still confuse you). I am also tickled
                                                        that at long last you certainly do understand the essence of my
                                                        magical calculation. Soon, I trust, as your comprehension
                                                        improves, the term magical will be replaced by elegant, as that is
                                                        more apropos. However, that moment awaits your
                                                        understanding of the simple logic which drives the inference,
                                                        and about which I should restate again that I am not emotionally
                                                        or financially beholden to its correctness. (Please find an
                                                        alternative to its conclusions; I will be just as happy in this case -
                                                        well maybe not quite.) I still have hope for you, so keep trying.

                                                        But first a few words on the discussion itself, its context and the
                                                        decorum of participants. As far as I can tell, no one participating
                                                        in this group is hostile to simulations being a useful tool for
                                                        analysis; I most certainly am not and have always enjoyed your
                                                        presentation of facts regarding your product - though now I have
                                                        growing questions of the substance of your magical sim. That
                                                        said, your penchant for aggression and lack of good faith in
                                                        addressing the concerns of others is nothing but offputting.
                                                        Case in point: the initial point I was making regarding the clear
                                                        and dominant superiority of 80s teams over 60s teams was
                                                        conditional on stipulated facts. It seems to me the courteous
                                                        and productive way to respond is to say "OK let's stipulate the
                                                        facts and address the theoretical argument, with the ultimate
                                                        factual (as opposed to theoretical) conclusion dependent on the
                                                        presentation of facts," as opposed to instead offering irrelevant
                                                        data series and condescending remarks. But whatever...on to
                                                        the substance.

                                                        First, here again, as they invoked no real controversy, are the
                                                        data and definitions I provided.

                                                        (The year refers to the end year of the season. "CP/game" is
                                                        "Common Possessions per Game". "P/CP" is "Points per
                                                        Common Possession". "P*/CP is the same stat except the
                                                        points are modified to subtract out the third point of completed
                                                        three pointers. Finally, "3pt effect" differences the two previous
                                                        columns.)

                                                        > Year CP/game P/CP P*/CP 3pt effect
                                                        > 57 116.4 .856 .856
                                                        > 58 124.7 .855 .855
                                                        > 59 124.5 .870 .870
                                                        > 60 131.2 .879 .879
                                                        > 61 132.9 .889 .889
                                                        > 62 131.4 .904 .904
                                                        > 63 124.5 .926 .926
                                                        > 64 121.5 .913 .913
                                                        > 65 122.4 .904 .904
                                                        > 66 126.1 .916 .916
                                                        > 67 126.6 .927 .927
                                                        > 68 124.8 .934 .934
                                                        > 69 121.7 .923 .923
                                                        > 70 122.0 .957 .957
                                                        > 71 119.7 .939 .939
                                                        > 72 116.4 .946 .946
                                                        > 73 114.7 .938 .938
                                                        > 74 111.7 .946 .946
                                                        > 75 108.5 .946 .946
                                                        > 76 109.6 .952 .952
                                                        > 77 110.5 .964 .964
                                                        > 78 111.0 .977 .977
                                                        > 79 109.7 1.005 1.005
                                                        > 80 107.3 1.019 1.012 .007
                                                        > 81 105.9 1.021 1.016 .005
                                                        > 82 104.7 1.037 1.031 .006
                                                        > 83 107.0 1.015 1.010 .005
                                                        > 84 105.7 1.042 1.036 .006
                                                        > 85 106.1 1.045 1.036 .008
                                                        > 86 106.2 1.038 1.029 .009
                                                        > 87 105.0 1.047 1.034 .014
                                                        > 88 103.5 1.045 1.030 .015
                                                        > 89 104.9 1.041 1.021 .020
                                                        > 90 102.4 1.045 1.024 .021
                                                        > 91 102.0 1.043 1.020 .022
                                                        > 92 100.7 1.046 1.021 .025
                                                        > 93 100.7 1.045 1.015 .030
                                                        > 94 98.7 1.028 .995 .033
                                                        > 95 96.8 1.048 .991 .057*
                                                        > 96 95.5 1.042 .980 .062*
                                                        > 97 93.9 1.032 .967 .064*
                                                        > 98 94.2 1.015 .968 .047
                                                        > 99 92.7 .987 .939 .048
                                                        > 00 96.7 1.008 .957 .050
                                                        > 01 95.1 .997 .946 .051
                                                        > 02 94.4 1.011 .956 .055

                                                        (Now before discussing trends and repeating the arguments, let
                                                        me lay out the sources and methods behind these statistics. All
                                                        data for the "NBA average" are from the Official NBA Guide.
                                                        "CP/game" is the following sum of terms (divided by games
                                                        played): Field Goal Attempts + 0.45 * Free Throw Attempts + 1.05
                                                        * Turnovers - 1.045 * Offensive Rebounds. What this statistic
                                                        represents again are the number of common possessions
                                                        between a team and its opponent, or alternatively expressed, the
                                                        number of continuous possessions - continuous meaning no
                                                        additional possession is counted on an offensive rebound. Why
                                                        the various factors. Possessions are disposed of as (1) field
                                                        goal attempts, (2) two shot free throw attempts (three shot free
                                                        throws are ignored) which I estimate as one half of 90% of all
                                                        attempts (the other 10% being technicals and attempts after
                                                        made shots) hence 0.45, (3) turnovers, where a 5% estimate of
                                                        team turnovers is added, and (4) offensive rebounds, where
                                                        4.5% is the estimate of team offensive rebounds. It should be
                                                        noted that none of the results are sensitive to the factors chosen
                                                        which is obvious as the last two terms effectively cancel each
                                                        other out.)

                                                        (For the missing turnover and offensive rebound series prior to
                                                        1974, I extrapolated using 1974 data. Specifically, for offensive
                                                        rebounds, I calculated an offensive rebounding percentage for
                                                        missed field goal attempts of 28.7 (and assumed a constant 5%
                                                        value for offensive rebounds of missed final free throws). This
                                                        should not be a controversial value as the percentage hovers
                                                        quite closely about 30%. And for the turnover series, I assumed
                                                        a stable relationship of turnovers to field goal attempts and two
                                                        point field goal attempts, and this value in 1974 was 0.198. In
                                                        this case, given the downward trend over time in turnover rate,
                                                        this value is almost certainly biased low which would have the
                                                        effect on the data of biasing CP/game down and P/CP up - that is
                                                        to say exaccerbating the trends I identify.)

                                                        So I began my discussion of the data with an actual calculation
                                                        of my original recollection, to which Bob responds....

                                                        ...so this is your magical brain storm as to why an average
                                                        1978-79 team is almost 14 points better than an average
                                                        1959-60 team??? you're blatantly stating, based on this one
                                                        lonely calculation, that:

                                                        "....the superiority of the average team in the early 80 (in this
                                                        case 1978-79) to its 60s counterpart was on the order of 10 to 12
                                                        points per game (at a modern game pace). This is equivalent to
                                                        how much better the best Bulls team was to the league
                                                        average....."

                                                        I say again: yes, yes, and yes, certainly to a first approximation
                                                        and absent any introduced counter-argument.

                                                        Bob then goes on to offer myriad calculations based on "this one
                                                        lonely calculation" comparing "undeniably" great teams with
                                                        "undeniably" average teams, with the rhetorical weight of his
                                                        preconceptions and anecdotes (but no statistics or even perish
                                                        the thought philosophy!) designed to persuade that the inference
                                                        behind the calculation (not the calculation itself) must, just must
                                                        be wrong.

                                                        So here we begin. What is this one lonely calculation? It is in
                                                        fact the average performance of the league. I suppose I must
                                                        agree, it is lonely, singular is a better word, in its breadth. But it
                                                        is the bottom line; there is no other for the issue in question.

                                                        That said, let me state unequivocally what I view the trends to be,
                                                        and after, I will go step by step through the chain of inference
                                                        which leads to the contentious conclusions. The trend in game
                                                        pace is not at issue, the game has slowed continuously over the
                                                        past 30 plus years. Agreed. There is, however, an apparent
                                                        controversy over the trends in offensive productivity (that there is
                                                        is somewhat mind-boggling to me - well not really when I think
                                                        about it.)

                                                        Points per common possession increase from 1960 (.879) and
                                                        come to a somewhat flat peak around 1984 or 1985 (1.045)
                                                        thereafter descending almost without exception to 2000. That
                                                        you cannot see this, Bob, I can only explain from reading your
                                                        remarks in two ways (besides the more cynical interpretation).
                                                        First, you apparently don't understand the importance of the
                                                        increasing usage of the 3 point shot in obscuring the series
                                                        trends. The three pointer is an "ad hoc" rule change which
                                                        directly biases scoring upwards (by design of course) and the
                                                        shallow learning curve on how to employ the shot efficiently
                                                        makes the plateau merely apparent, not real. Second, and more
                                                        gratuitously, you ignore the particular bias of moving the three
                                                        point line in between 1995 and 1997. These effects on the
                                                        series are clear and were precisely why they were presented.
                                                        And finally, you support your notion that there are no trends in
                                                        productivity since 1979 (though again this is not a meaningful
                                                        endpoint for discussion) by arguing that the deviations in
                                                        productivity within the period are somehow not significant. This
                                                        view is simply untenable. Taking a maximum rise of about 0.04
                                                        points per common possession (between 1979 and 1985) this
                                                        translates to an average increase - I would say improvement - of
                                                        about 4 points per game. Yes, four is a small number compared
                                                        to 13.5 or 1,000,003, but in the context of NBA basketball, the
                                                        margin is huge.

                                                        But I suppose that you would say that it begs the question. Is it
                                                        in fact an improvement or does it - according to your belief - imply
                                                        nothing, with the quality of the league on average ever
                                                        unchanging?

                                                        Perhaps now, before re-explaining the argument as to why the
                                                        game has decidedly improved over time, it would be worthwhile,
                                                        for the purpose of contrast, to flesh out the implication of your
                                                        view (yes, I know, it is my interpretation of your view) in the
                                                        context of the evidence (even allowing for our divergent views of
                                                        latter-day trends.) In Bob's world, a change in measured
                                                        offensive productivity means nothing, the NBA resides in a state
                                                        of God-given equipoise. So offensive productivity increases 15%
                                                        over 25 years. Guess what? That just happens to be a 7.5%
                                                        increase in true offensive productivity and a 7.5% decrease in
                                                        true defensive productivity. (And why again did defenses get
                                                        worse?) Same story for an increase of 1%, 2%, 3%, 4%, 5%, 6%,
                                                        7%...Pick a number; it doesn't matter; let's just run the "sim" with
                                                        actual numbers!

                                                        The question we return to then is how one should interpret
                                                        changes in offensive (equivalently defensive) productivity that are
                                                        observed in the data, dramatic or otherwise. But now, and note
                                                        the change of subject, the discussion is strictly about theoretical
                                                        issues; it has nothing to do with any particular numbers. Here
                                                        we go. Now pay attention, and please feel free to respond
                                                        directly to what is argued here, no side-stepping the issues, no
                                                        introduction of irrelevant topics.

                                                        Suppose we see a change, an increase in average offensive
                                                        productivity or alternatively a decrease in average defensive
                                                        productivity. How can we say whether offenses are getting better
                                                        or that defenses are getting worse. Absent any additional
                                                        information, we cannot. Noting that turnover rates drop is
                                                        suggestive, it would appear that offenses are getting better at
                                                        protecting the ball, but that does not negate the theoretical
                                                        justification of arguing that maybe defenses are simply
                                                        increasingly inept at stealing the ball. So appeals to
                                                        intermediate statistics yield no resolution to the argument.

                                                        Enter the "pace of game" variable. This data series has the
                                                        property in certain instances (not in all instances) to identify
                                                        whether or not observed changes in offensive productivity are net
                                                        improvements. In particular, when the pace of the game slows,
                                                        any increase in offensive productivity represents a net
                                                        improvement in offensive play. Why? The theory is this.

                                                        All else equal, if the average pace of the game slows, it means
                                                        that offensive productivity must fall. Why? If the time of the
                                                        average possession is increasing, it means either that there are
                                                        fewer fast-breaks in the mix or that within half-court offenses
                                                        more time elapses before a shot is taken. The necessary
                                                        consequence of these two possible outcomes is the same,
                                                        offensive productivity must fall. In the first instance, fewer
                                                        fast-breaks mean that on-average higher percentage shots are
                                                        being eliminated. In the second instance, longer half-court
                                                        possessions mean that the quality of shot that was previously
                                                        available earlier in the possession are not available and more
                                                        time is taken to yield, in expectation, at least no better of a shot.

                                                        (Understanding this, we can also note a circumstance where the
                                                        pace of game variable cannot be used to identify net progress in
                                                        the offensive productivity variable. When offensive productivity
                                                        falls along with the pace of the game - what happened from the
                                                        mid-'80s onward - according to the theory it can mean that either
                                                        defenses got on net better, with offenses also possibly
                                                        improving, or it can mean that offenses simply got worse. In the
                                                        instance of the actual NBA history, I don't think the latter
                                                        interpretation is justified, and as suggestive evidence consider
                                                        the growing importance of the three point shot; what to me is
                                                        clearly incremental progress toward a newly optimal strategy -
                                                        hardly the hallmark of technological retrogression.)

                                                        Thus, if a falling game pace is observed and an increase in
                                                        offensive productivity is observed, the latter is necessarily a net
                                                        gain in offensive productivity. The true improvement in offense
                                                        might be higher still, compensated by an improvement in
                                                        defense, but the actual statistic represents a lower bound on
                                                        offensive improvement.

                                                        Bob, that is the theoretical argument. It is what must be
                                                        responded to on theoretical grounds if you are serious in your
                                                        objections to the empirical conclusions offered. And to date the
                                                        theory has not been addressed by you. Fond recollections of the
                                                        '67 Sixers are insufficient.

                                                        More generally though, in your quest to offer a serious objection
                                                        to the overall conclusion -besides finding a flaw in the magical
                                                        theoretical argument - let me try to help you a bit by providing a
                                                        possible category for you to consider. Perhaps there are some
                                                        rules change (akin to the introduction of the three point shot) that
                                                        affect the actual interpretation of the data over the sweep of
                                                        history considered. After all, see how the misinterpretation of the
                                                        three point data flummoxed you? Perhaps there are rule
                                                        changes, slowly adapted to, that seen in proper perspective
                                                        would attenuate the huge gains in offensive productivity from the
                                                        late '60s to the mid-'80s. Identifying these would put the
                                                        magnitude, but almost certainly not the existance, of the net
                                                        offensive improvement in question. Anyway, think a little before
                                                        you respond. And, of course, please provide data.

                                                        And as always, thank you for your consideration.
                                                      • bchaikin@aol.com
                                                        Given that I started off recalling data over the 60s and 70s, let me take 60 and 79 as endpoints to begin the discussion. Note a drop in game pace from 131.2
                                                        Message 27 of 29 , Jan 31, 2003
                                                        • 0 Attachment

                                                          Given that I started off recalling data over the 60s and 70s, let me take '60 and '79 as endpoints to begin the discussion. Note a drop in game pace from 131.2 to 109.7
                                                          possessions per game, a decrease of 15.6%. And during which time offensive productivity increased 11% (.879 to 1.005). Put another way, the average team in 1979, playing at its slower pace would be expected to beat the average team of 1960 by 13.82 points per game (.126 P/CP * 109.7 CP/game).

                                                          ...so this is your magical brain storm as to why an average 1978-79 team is almost 14 points better than an average 1959-60 team??? you're blatantly stating, based on this one lonely calculation, that:

                                                          "....the superiority of the average team in the early 80 (in this case 1978-79) to its 60s counterpart was on the order of 10 to 12 points per game (at a modern game pace). This is equivalent to how much better the best Bulls team was to the league
                                                          average....."

                                                          I say again: yes, yes, and yes, certainly to a first approximation and absent any introduced counter-argument.

                                                          your 1959-60 pts/poss is .879. your 1978-79 pts/poss is 1.005. you are saying that:

                                                          1 - (.879)/(1.005) = 0.126 difference in pts/poss between 59-60 and 78-79...

                                                          you are then multiplying this pts/poss difference by the 78-79 game pace:

                                                          0.126 x 109.7 = 13.82 pts/g

                                                          and you are then stating that because of this percent difference that since these pts/poss numbers are the average for their respective season, that an average team in 78-79 would beat an average team in 59-60 by almost 14 points....

                                                          but like professor morbius in the forbidden planet, you are clueless...

                                                          this calculation of yours is absolutely meaningless, because you fail to realize that pts/poss, while a measure of "offensive productivity", is at the same time a measure of what the defense allows per possession. you are measuring simply one side of the ball, and looking only at offense, and your calculation assumes that the defensive pts/poss remained the same over that time...

                                                          pts/poss scored is a relative number, what the offense scores against the defense on average, or what the defense allows the offense to score on average. it is a relative number stating the "balance" between what the offense produces and what the defense gives up...

                                                          in 59-60 defenses allowed only 0.879 pts/poss, as compared to in 78-79 defenses allowing 1.005 pts/poss. no matter how you want to look at it, a defense giving up just 0.879 pts/poss is "better" than a defense that gives up 1.005 pts/poss - in any game where two teams each have the same number of possessions, the team giving up the least amount of pts/poss will win. thus the avg team in 59-60, based on your meaningless logic, states that 59-60 had the better avg defensive teams...

                                                          stating that an offensive productivity of 1.005 in 78-79 is better than 0.879 in 59-60 is exactly the same as saying a defense allowing 1.005 pts/poss in 78-79 is worse than a defense allowing just 0.879 pts/poss in 59-60...

                                                          this is exactly the same arguement you are using to say teams of 78-79 are better than teams of 59-60, simply because the avg team pts/poss is greater, 1.005 to 0.879. it has no basis in fact. using your formula one can say the teams of 59-60 are 13.82 better on defense than teams of 78-79, and thus if they played the avg 59-60 team would defeat the avg 78-79 team by that 13.82 pts/g, actually even more because the game pace was greater in 59-60...

                                                          0.126 x 131.2 = 16.5 pts/g

                                                          thus an avg 59-60 team, because of its "better" defense, would outscore an avg 78-79 team by 16.5 pts/g, normalized for the 59-60 game pace. this manipulation of the numbers is worthless...

                                                          a completely meaningless calculation that has no basis in fact....

                                                          bob chaikin
                                                          bchaikin@...






                                                        • schtevie2003 <schtevie@hotmail.com>
                                                          Bob, I read your posting, shaking my head in disbelief. What could possibly be your motivation for not responding to any of the substantive points in the
                                                          Message 28 of 29 , Feb 3, 2003
                                                          • 0 Attachment
                                                            Bob, I read your posting, shaking my head in disbelief. What
                                                            could possibly be your motivation for not responding to any of the
                                                            substantive points in the previous posting? They were not hard
                                                            to identify in the text; I pointed them out as they arose, inviting a
                                                            response, noting that for an alternative interpretation of the data
                                                            to prevail that these were the relevant points at issue. But a
                                                            complete lack of response is what you offered. In fact, all you
                                                            posted was a numerical illustration of the problem that I initially
                                                            presented (way back when)! And that problem is that one cannot
                                                            identify progress or regress based on movements in average
                                                            offensive (equivalently defensive) productivity alone.
                                                            Congratulations on your having mastered the first sentence of
                                                            paragraph one, now proceed onwards!

                                                            I am left with the belief that the only plausible answer for your
                                                            lack of responsiveness (if not the rudeness) is that you are
                                                            entirely cynical. (After all, your stated profession demands in
                                                            training that you have the intellect to understand the type of
                                                            arguments presented - based as they are on simplest math and
                                                            logic. And you have shown yourself to be very dogged pursuing
                                                            evidence - all that S.J. Gould stuff - when you think you have a
                                                            case.) I can only think that you have seen the error of your ways
                                                            and are hoping no one else has (?) and are blustering to the
                                                            end, hoping that I will tire of repeating the argument - and
                                                            imploring you to respond - thereby taking some odd comfort in
                                                            being the last one to opine. Such an approach has its
                                                            consequences however and ones I would be very concerned
                                                            about them if I were you. In particular, your credibility erodes. At
                                                            best (?) one is left with the misimpression that you lack a certain
                                                            acuity. At worst is the inference that you lack trustworthiness,
                                                            being willing to obfuscate for the purposes of protecting a vested
                                                            interest.

                                                            So here we go again - this time with much greater brevity.

                                                            To be interpreted: the rise (to the mid-80s) and fall (thereafter) of
                                                            offensive productivity (well actually just the rise, but the fall - I
                                                            presume - is at least finally admitted to as being fact?)

                                                            Interpretation offered: falling game pace identifies observed
                                                            increase is offensive productivity as a net (that is lower bound)
                                                            improvement in offensive "technology" (that is distinct from player
                                                            height, strength, or athleticism) as opposed to a decrease in
                                                            defensive "technology".

                                                            Basis of inference: Possessions by definition consist exclusively
                                                            of fast-breaks and non-fast-breaks (that is half-court set
                                                            offenses). By definition fast-breaks take less time and yield
                                                            higher points per possession. Thus, all else equal (READ: IF
                                                            THERE HAS BEEN NO CHANGE IN OFFENSIVE
                                                            "TECHNOLOGY") if the game slows, this means that by
                                                            definition there are either fewer fast-breaks or longer half-court
                                                            possessions. In either of these two instances, the implication is
                                                            that average offensive productivity falls. THUS, THERE MUST
                                                            HAVE BEEN A CHANGE IN OFFENSIVE TECHNOLOGY.

                                                            Bob, there is the argument. Deal with it (and all the better if no
                                                            gratuitous insults are offered) or just sit down.

                                                            Oh yes, one final thing. If behind your inability to deal with the
                                                            arguments is your inquietude with the jarring statistical
                                                            conclusion (12 to 14 points, blah, blah, blah) perhaps it is
                                                            comforting to know that I share it to a certain degree, but absent
                                                            ameliorating explanations (or some error of my ways) I feel
                                                            obliged to accept the calculation as is.

                                                            That said, it would be nice if there were some other evidence of a
                                                            time machine sort that could to some degree corroborate the
                                                            logical inference above. And perhaps (only perhaps) there is.
                                                            Consider two cases:

                                                            1. Teams that went retro to their detriment (thanks to Mike G. for
                                                            the idea). As a possible (and I only say possible) case in point,
                                                            the '90 Nuggets became the '91 Nutties and increased their
                                                            possessions per game by 8.4 and dropped their points per
                                                            possession by .033. Now, if one looks at these changes and
                                                            links them to movements in the league averages these are
                                                            equivalent to going back in time from 1990 to 1978 in the former
                                                            case and to between '78 and '79 in the latter. Now, whether any
                                                            ultimately persuasive evidence can ever be gleaned from looking
                                                            at the basketcases on the NBA over time is not clear to me, but
                                                            it's a thought in progress.

                                                            2. More persuasive to me now is a reasoned interpretation of
                                                            the performance of NBA All-Stars in Olympic/World Competition.
                                                            Witness how over a mere decade, the rest of the world went from
                                                            being whipping boys to being serious competitors. (Sorry, no
                                                            hard data on average victory margins of European and South
                                                            American elite vs. NBA, but it must show a movement of at least
                                                            10 points per game on average.) So what would the analogy be?

                                                            In the case of the NBA history in question, the presumption is
                                                            that greatness is greatness no matter when, and it is
                                                            unreasonable to assume improvement, especially dramatic
                                                            improvement, over relatively short periods of time. As in "are you
                                                            trying to tell me that the average NBA team in the early 90s was
                                                            as good or better than the 67 Warriors, clearly one of the greatest
                                                            teams ever?"

                                                            Against this we have witnessed just such dramatic improvement
                                                            against relatively constant NBA talent in a not-too-distantly
                                                            related theater - though arguably it can in large measure be
                                                            attributed to improvements in foreign talent as well as in
                                                            organization (though wasn't the presumption that talent
                                                            increases weren't that plausible either?)

                                                            The tentative upshot: massive changes can happen in relatively
                                                            short periods of time, to the surprise and sadness of many.

                                                            ***************

                                                            --- In APBR_analysis@yahoogroups.com, bchaikin@a... wrote:
                                                            >
                                                            > Given that I started off recalling data over the 60s and 70s, let
                                                            me take '60
                                                            > and '79 as endpoints to begin the discussion. Note a drop in
                                                            game pace from
                                                            > 131.2 to 109.7
                                                            > possessions per game, a decrease of 15.6%. And during
                                                            which time offensive
                                                            > productivity increased 11% (.879 to 1.005). Put another way,
                                                            the average team
                                                            > in 1979, playing at its slower pace would be expected to beat
                                                            the average
                                                            > team of 1960 by 13.82 points per game (.126 P/CP * 109.7
                                                            CP/game).
                                                            >
                                                            > ...so this is your magical brain storm as to why an average
                                                            1978-79 team is
                                                            > almost 14 points better than an average 1959-60 team???
                                                            you're blatantly
                                                            > stating, based on this one lonely calculation, that:
                                                            >
                                                            > "....the superiority of the average team in the early 80 (in this
                                                            case
                                                            > 1978-79) to its 60s counterpart was on the order of 10 to 12
                                                            points per game
                                                            > (at a modern game pace). This is equivalent to how much
                                                            better the best Bulls
                                                            > team was to the league
                                                            > average....."
                                                            >
                                                            > I say again: yes, yes, and yes, certainly to a first approximation
                                                            and absent
                                                            > any introduced counter-argument.
                                                            >
                                                            > your 1959-60 pts/poss is .879. your 1978-79 pts/poss is 1.005.
                                                            you are saying
                                                            > that:
                                                            >
                                                            > 1 - (.879)/(1.005) = 0.126 difference in pts/poss between 59-60
                                                            and 78-79...
                                                            >
                                                            > you are then multiplying this pts/poss difference by the 78-79
                                                            game pace:
                                                            >
                                                            > 0.126 x 109.7 = 13.82 pts/g
                                                            >
                                                            > and you are then stating that because of this percent difference
                                                            that since
                                                            > these pts/poss numbers are the average for their respective
                                                            season, that an
                                                            > average team in 78-79 would beat an average team in 59-60
                                                            by almost 14
                                                            > points....
                                                            >
                                                            > but like professor morbius in the forbidden planet, you are
                                                            clueless...
                                                            >
                                                            > this calculation of yours is absolutely meaningless, because
                                                            you fail to
                                                            > realize that pts/poss, while a measure of "offensive
                                                            productivity", is at the
                                                            > same time a measure of what the defense allows per
                                                            possession. you are
                                                            > measuring simply one side of the ball, and looking only at
                                                            offense, and your
                                                            > calculation assumes that the defensive pts/poss remained the
                                                            same over that
                                                            > time...
                                                            >
                                                            > pts/poss scored is a relative number, what the offense scores
                                                            against the
                                                            > defense on average, or what the defense allows the offense to
                                                            score on
                                                            > average. it is a relative number stating the "balance" between
                                                            what the
                                                            > offense produces and what the defense gives up...
                                                            >
                                                            > in 59-60 defenses allowed only 0.879 pts/poss, as compared
                                                            to in 78-79
                                                            > defenses allowing 1.005 pts/poss. no matter how you want to
                                                            look at it, a
                                                            > defense giving up just 0.879 pts/poss is "better" than a
                                                            defense that gives
                                                            > up 1.005 pts/poss - in any game where two teams each have
                                                            the same number of
                                                            > possessions, the team giving up the least amount of pts/poss
                                                            will win. thus
                                                            > the avg team in 59-60, based on your meaningless logic,
                                                            states that 59-60 had
                                                            > the better avg defensive teams...
                                                            >
                                                            > stating that an offensive productivity of 1.005 in 78-79 is better
                                                            than 0.879
                                                            > in 59-60 is exactly the same as saying a defense allowing
                                                            1.005 pts/poss in
                                                            > 78-79 is worse than a defense allowing just 0.879 pts/poss in
                                                            59-60...
                                                            >
                                                            > this is exactly the same arguement you are using to say teams
                                                            of 78-79 are
                                                            > better than teams of 59-60, simply because the avg team
                                                            pts/poss is greater,
                                                            > 1.005 to 0.879. it has no basis in fact. using your formula one
                                                            can say the
                                                            > teams of 59-60 are 13.82 better on defense than teams of
                                                            78-79, and thus if
                                                            > they played the avg 59-60 team would defeat the avg 78-79
                                                            team by that 13.82
                                                            > pts/g, actually even more because the game pace was greater
                                                            in 59-60...
                                                            >
                                                            > 0.126 x 131.2 = 16.5 pts/g
                                                            >
                                                            > thus an avg 59-60 team, because of its "better" defense, would
                                                            outscore an
                                                            > avg 78-79 team by 16.5 pts/g, normalized for the 59-60 game
                                                            pace. this
                                                            > manipulation of the numbers is worthless...
                                                            >
                                                            > a completely meaningless calculation that has no basis in
                                                            fact....
                                                            >
                                                            > bob chaikin
                                                            > bchaikin@b...
                                                          • Dean Oliver <deano@rawbw.com>
                                                            All right! For whatever reason there is a disconnect here on this topic. Let s hold off a while on this train of thought and converse on some other things.
                                                            Message 29 of 29 , Feb 3, 2003
                                                            • 0 Attachment
                                                              All right! For whatever reason there is a disconnect here on this
                                                              topic. Let's hold off a while on this train of thought and converse
                                                              on some other things. It's getting to some rather uninformative long-
                                                              winded counterproductive stuff.

                                                              So let's not talk about this thing for a month or so. Hopefully some
                                                              of these other tracks will address other issues that may lead to
                                                              productive discussion...LATER!!!

                                                              DeanO
                                                              Moderator

                                                              --- In APBR_analysis@yahoogroups.com, "schtevie2003 <schtevie@h...>"
                                                              <schtevie@h...> wrote:
                                                              > Bob, I read your posting, shaking my head in disbelief. What
                                                              > could possibly be your motivation for not responding to any of the
                                                              > substantive points in the previous posting? They were not hard
                                                              > to identify in the text; I pointed them out as they arose, inviting
                                                              a
                                                              > response, noting that for an alternative interpretation of the data
                                                              > to prevail that these were the relevant points at issue. But a
                                                              > complete lack of response is what you offered. In fact, all you
                                                              > posted was a numerical illustration of the problem that I initially
                                                              > presented (way back when)! And that problem is that one cannot
                                                              > identify progress or regress based on movements in average
                                                              > offensive (equivalently defensive) productivity alone.
                                                              > Congratulations on your having mastered the first sentence of
                                                              > paragraph one, now proceed onwards!
                                                              >
                                                              > I am left with the belief that the only plausible answer for your
                                                              > lack of responsiveness (if not the rudeness) is that you are
                                                              > entirely cynical. (After all, your stated profession demands in
                                                              > training that you have the intellect to understand the type of
                                                              > arguments presented - based as they are on simplest math and
                                                              > logic. And you have shown yourself to be very dogged pursuing
                                                              > evidence - all that S.J. Gould stuff - when you think you have a
                                                              > case.) I can only think that you have seen the error of your ways
                                                              > and are hoping no one else has (?) and are blustering to the
                                                              > end, hoping that I will tire of repeating the argument - and
                                                              > imploring you to respond - thereby taking some odd comfort in
                                                              > being the last one to opine. Such an approach has its
                                                              > consequences however and ones I would be very concerned
                                                              > about them if I were you. In particular, your credibility erodes.
                                                              At
                                                              > best (?) one is left with the misimpression that you lack a certain
                                                              > acuity. At worst is the inference that you lack trustworthiness,
                                                              > being willing to obfuscate for the purposes of protecting a vested
                                                              > interest.
                                                              >
                                                              > So here we go again - this time with much greater brevity.
                                                              >
                                                              > To be interpreted: the rise (to the mid-80s) and fall (thereafter)
                                                              of
                                                              > offensive productivity (well actually just the rise, but the fall -
                                                              I
                                                              > presume - is at least finally admitted to as being fact?)
                                                              >
                                                              > Interpretation offered: falling game pace identifies observed
                                                              > increase is offensive productivity as a net (that is lower bound)
                                                              > improvement in offensive "technology" (that is distinct from player
                                                              > height, strength, or athleticism) as opposed to a decrease in
                                                              > defensive "technology".
                                                              >
                                                              > Basis of inference: Possessions by definition consist exclusively
                                                              > of fast-breaks and non-fast-breaks (that is half-court set
                                                              > offenses). By definition fast-breaks take less time and yield
                                                              > higher points per possession. Thus, all else equal (READ: IF
                                                              > THERE HAS BEEN NO CHANGE IN OFFENSIVE
                                                              > "TECHNOLOGY") if the game slows, this means that by
                                                              > definition there are either fewer fast-breaks or longer half-court
                                                              > possessions. In either of these two instances, the implication is
                                                              > that average offensive productivity falls. THUS, THERE MUST
                                                              > HAVE BEEN A CHANGE IN OFFENSIVE TECHNOLOGY.
                                                              >
                                                              > Bob, there is the argument. Deal with it (and all the better if no
                                                              > gratuitous insults are offered) or just sit down.
                                                              >
                                                              > Oh yes, one final thing. If behind your inability to deal with the
                                                              > arguments is your inquietude with the jarring statistical
                                                              > conclusion (12 to 14 points, blah, blah, blah) perhaps it is
                                                              > comforting to know that I share it to a certain degree, but absent
                                                              > ameliorating explanations (or some error of my ways) I feel
                                                              > obliged to accept the calculation as is.
                                                              >
                                                              > That said, it would be nice if there were some other evidence of a
                                                              > time machine sort that could to some degree corroborate the
                                                              > logical inference above. And perhaps (only perhaps) there is.
                                                              > Consider two cases:
                                                              >
                                                              > 1. Teams that went retro to their detriment (thanks to Mike G. for
                                                              > the idea). As a possible (and I only say possible) case in point,
                                                              > the '90 Nuggets became the '91 Nutties and increased their
                                                              > possessions per game by 8.4 and dropped their points per
                                                              > possession by .033. Now, if one looks at these changes and
                                                              > links them to movements in the league averages these are
                                                              > equivalent to going back in time from 1990 to 1978 in the former
                                                              > case and to between '78 and '79 in the latter. Now, whether any
                                                              > ultimately persuasive evidence can ever be gleaned from looking
                                                              > at the basketcases on the NBA over time is not clear to me, but
                                                              > it's a thought in progress.
                                                              >
                                                              > 2. More persuasive to me now is a reasoned interpretation of
                                                              > the performance of NBA All-Stars in Olympic/World Competition.
                                                              > Witness how over a mere decade, the rest of the world went from
                                                              > being whipping boys to being serious competitors. (Sorry, no
                                                              > hard data on average victory margins of European and South
                                                              > American elite vs. NBA, but it must show a movement of at least
                                                              > 10 points per game on average.) So what would the analogy be?
                                                              >
                                                              > In the case of the NBA history in question, the presumption is
                                                              > that greatness is greatness no matter when, and it is
                                                              > unreasonable to assume improvement, especially dramatic
                                                              > improvement, over relatively short periods of time. As in "are you
                                                              > trying to tell me that the average NBA team in the early 90s was
                                                              > as good or better than the 67 Warriors, clearly one of the greatest
                                                              > teams ever?"
                                                              >
                                                              > Against this we have witnessed just such dramatic improvement
                                                              > against relatively constant NBA talent in a not-too-distantly
                                                              > related theater - though arguably it can in large measure be
                                                              > attributed to improvements in foreign talent as well as in
                                                              > organization (though wasn't the presumption that talent
                                                              > increases weren't that plausible either?)
                                                              >
                                                              > The tentative upshot: massive changes can happen in relatively
                                                              > short periods of time, to the surprise and sadness of many.
                                                              >
                                                              > ***************
                                                              >
                                                              > --- In APBR_analysis@yahoogroups.com, bchaikin@a... wrote:
                                                              > >
                                                              > > Given that I started off recalling data over the 60s and 70s, let
                                                              > me take '60
                                                              > > and '79 as endpoints to begin the discussion. Note a drop in
                                                              > game pace from
                                                              > > 131.2 to 109.7
                                                              > > possessions per game, a decrease of 15.6%. And during
                                                              > which time offensive
                                                              > > productivity increased 11% (.879 to 1.005). Put another way,
                                                              > the average team
                                                              > > in 1979, playing at its slower pace would be expected to beat
                                                              > the average
                                                              > > team of 1960 by 13.82 points per game (.126 P/CP * 109.7
                                                              > CP/game).
                                                              > >
                                                              > > ...so this is your magical brain storm as to why an average
                                                              > 1978-79 team is
                                                              > > almost 14 points better than an average 1959-60 team???
                                                              > you're blatantly
                                                              > > stating, based on this one lonely calculation, that:
                                                              > >
                                                              > > "....the superiority of the average team in the early 80 (in this
                                                              > case
                                                              > > 1978-79) to its 60s counterpart was on the order of 10 to 12
                                                              > points per game
                                                              > > (at a modern game pace). This is equivalent to how much
                                                              > better the best Bulls
                                                              > > team was to the league
                                                              > > average....."
                                                              > >
                                                              > > I say again: yes, yes, and yes, certainly to a first
                                                              approximation
                                                              > and absent
                                                              > > any introduced counter-argument.
                                                              > >
                                                              > > your 1959-60 pts/poss is .879. your 1978-79 pts/poss is 1.005.
                                                              > you are saying
                                                              > > that:
                                                              > >
                                                              > > 1 - (.879)/(1.005) = 0.126 difference in pts/poss between 59-60
                                                              > and 78-79...
                                                              > >
                                                              > > you are then multiplying this pts/poss difference by the 78-79
                                                              > game pace:
                                                              > >
                                                              > > 0.126 x 109.7 = 13.82 pts/g
                                                              > >
                                                              > > and you are then stating that because of this percent difference
                                                              > that since
                                                              > > these pts/poss numbers are the average for their respective
                                                              > season, that an
                                                              > > average team in 78-79 would beat an average team in 59-60
                                                              > by almost 14
                                                              > > points....
                                                              > >
                                                              > > but like professor morbius in the forbidden planet, you are
                                                              > clueless...
                                                              > >
                                                              > > this calculation of yours is absolutely meaningless, because
                                                              > you fail to
                                                              > > realize that pts/poss, while a measure of "offensive
                                                              > productivity", is at the
                                                              > > same time a measure of what the defense allows per
                                                              > possession. you are
                                                              > > measuring simply one side of the ball, and looking only at
                                                              > offense, and your
                                                              > > calculation assumes that the defensive pts/poss remained the
                                                              > same over that
                                                              > > time...
                                                              > >
                                                              > > pts/poss scored is a relative number, what the offense scores
                                                              > against the
                                                              > > defense on average, or what the defense allows the offense to
                                                              > score on
                                                              > > average. it is a relative number stating the "balance" between
                                                              > what the
                                                              > > offense produces and what the defense gives up...
                                                              > >
                                                              > > in 59-60 defenses allowed only 0.879 pts/poss, as compared
                                                              > to in 78-79
                                                              > > defenses allowing 1.005 pts/poss. no matter how you want to
                                                              > look at it, a
                                                              > > defense giving up just 0.879 pts/poss is "better" than a
                                                              > defense that gives
                                                              > > up 1.005 pts/poss - in any game where two teams each have
                                                              > the same number of
                                                              > > possessions, the team giving up the least amount of pts/poss
                                                              > will win. thus
                                                              > > the avg team in 59-60, based on your meaningless logic,
                                                              > states that 59-60 had
                                                              > > the better avg defensive teams...
                                                              > >
                                                              > > stating that an offensive productivity of 1.005 in 78-79 is
                                                              better
                                                              > than 0.879
                                                              > > in 59-60 is exactly the same as saying a defense allowing
                                                              > 1.005 pts/poss in
                                                              > > 78-79 is worse than a defense allowing just 0.879 pts/poss in
                                                              > 59-60...
                                                              > >
                                                              > > this is exactly the same arguement you are using to say teams
                                                              > of 78-79 are
                                                              > > better than teams of 59-60, simply because the avg team
                                                              > pts/poss is greater,
                                                              > > 1.005 to 0.879. it has no basis in fact. using your formula one
                                                              > can say the
                                                              > > teams of 59-60 are 13.82 better on defense than teams of
                                                              > 78-79, and thus if
                                                              > > they played the avg 59-60 team would defeat the avg 78-79
                                                              > team by that 13.82
                                                              > > pts/g, actually even more because the game pace was greater
                                                              > in 59-60...
                                                              > >
                                                              > > 0.126 x 131.2 = 16.5 pts/g
                                                              > >
                                                              > > thus an avg 59-60 team, because of its "better" defense, would
                                                              > outscore an
                                                              > > avg 78-79 team by 16.5 pts/g, normalized for the 59-60 game
                                                              > pace. this
                                                              > > manipulation of the numbers is worthless...
                                                              > >
                                                              > > a completely meaningless calculation that has no basis in
                                                              > fact....
                                                              > >
                                                              > > bob chaikin
                                                              > > bchaikin@b...
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