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Re: Major Update of WINVAL Ratings Through 2003-04

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  • dan_t_rosenbaum
    Dear DanD and JohnH: First of all, in comparing the game with an 11 point margin with 1 minute left in the third versus a game with a 4 point margin with 11
    Message 1 of 17 , May 2, 2004
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      Dear DanD and JohnH:

      First of all, in comparing the game with an 11 point margin with 1
      minute left in the third versus a game with a 4 point margin with 11
      minutes left in the fourth, here is what my formula comes up with.

      11 point margin, 1 minute left in third: 9.0
      4 point margin, 11 minutes left in fourth: 10.8

      After I normalize the weights so that the average weight in the
      fourth quarter is the same as the rest of the game, here is what I
      end up with (with the average weight being 1).

      11 point margin, 1 minute left in third: 1.00
      4 point margin, 11 minutes left in fourth: 1.29

      So I am counting latter situation much heavier.

      And on the matter of not counting garbage time at all. I could set
      a minimum weight so that every observation is counted, but then I
      suspect there are going to be a lot of people complain about me
      measuring a bunch of garbage time phenoms. It is a bit of a no-win
      situation.

      But this is not a trivial issue. Here is the distribution of the
      weights. So 9.2 percent of the minutes played (4.5 minutes per
      game) are garbage minutes that according to my weighting system get
      zero weight. Seventy percent of the zero weight minutes take place
      in the fourth quarter, where they make up 28.3 percent of minutes
      played.

      Range Percent Cumulative Percent
      ----------------------------------------------------
      0 9.2 9.2
      0.0-0.1 0.3 9.5
      0.1-0.2 0.9 10.4
      0.2-0.3 1.2 11.6
      0.3-0.4 1.2 12.8
      0.4-0.5 1.5 14.3
      0.5-0.6 1.7 16.1
      0.6-0.7 1.8 17.9
      0.7-0.8 2.2 20.1
      0.8-0.9 2.6 22.7
      0.9-1.0 0.5 23.2
      1.0-1.1 3.0 26.2
      1.1-1.2 62.5 88.8
      1.2-1.3 0.8 89.5
      1.3-1.4 1.4 91.0
      1.4-1.5 1.3 92.3
      1.5-1.6 1.4 93.7
      1.6-1.7 1.3 95.0
      1.7-1.8 1.2 96.2
      1.8-1.9 1.3 97.5
      1.9-2.0 0.9 98.4
      2.0-2.1 0.6 98.9
      2.1-2.2 0.4 99.3
      2.2-2.3 0.2 99.5
      2.3-2.4 0.5 100.0

      Best wishes,
      Dan

      --- In APBR_analysis@yahoogroups.com, "Daniel Dickey"
      <danthestatman@h...> wrote:
      >
      >
      >
      > >From: "dan_t_rosenbaum" <rosenbaum@u...>
      > >Reply-To: APBR_analysis@yahoogroups.com
      > >To: APBR_analysis@yahoogroups.com
      > >Subject: [APBR_analysis] Re: Major Update of WINVAL Ratings
      Through 2003-04
      > >Date: Thu, 29 Apr 2004 18:02:03 -0000
      >
      > >Here is my exact code. Clock measures the minutes elapsed in the
      > >game at the beginning of the observation. Three minutes left in
      the
      > >game (in regulation or in overtime) is counted as 45. Margin is
      the
      > >absolute value of the difference in scores at the beginning of the
      > >observation.
      > >
      > >ptime=max(0,(clock-36)/12);
      > >marg10=10-ptime*7;
      > >wgt=10*(1+ptime)*max(0,min(1,(1-(margin/marg10-1))));
      > >
      > >Basically, in the first three quarters, full weight is given to
      any
      > >part of a game where the margin is less than 10 and no weight is
      > >given if it is more than 20. Between 10 and 20, the weight is
      phased
      > >from full to zero.
      > >
      > >This is basically what happens in the fourth quarter as well,
      except
      > >that I decrease the margin from 10 (20) to 3 (6) from the
      beginning
      > >to the end of the fourth quarter. Also, ceteris paribus, the end
      of
      > >the quarter counts more than the beginning of the quarter.
      > >
      > >At the end of all of this, I renormalize the weights so that on
      > >average minutes in the fourth quarter count the same as those in
      the
      > >first three quarters.
      >
      > So a 4 point lead with 11 minutes left in the game has "less"
      value than a
      > 11 point lead with 13 minutes left in the game? Of course - I
      very well
      > could be reading this wrong.
      >
      > I also tend to think that EVERY minute should count just a little
      bit - EVEN
      > if it's in a blowout. These garbage players aren't going to not
      try (if
      > they wanna play in the future) - and it doesn't seem quite fair
      that a guy
      > could come in and play extremely well for 5 minutes and not have
      it count at
      > all. I mean - I know that garbage time had no true value to the
      team
      > win/loss wise - but doesn't it show a little bit the value of the
      player
      > still?
      >
      > Maybe this is part of the Frahm situation? He has so few minutes -
      and
      > probably most of them are garbage time. Maybe his poorer play
      just happened
      > during this time - and his better play happened the few minutes
      (percentage
      > wise) that counted?
      >
      > _________________________________________________________________
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    • tajallie@hotmail.com
      ... any ... on ... previously ... I am not sure that true . .I think the cause and effect is when Frahm plays well (read shoots well) he get to stay in the
      Message 2 of 17 , May 3, 2004
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        --- In APBR_analysis@yahoogroups.com, "Kevin Pelton" <kpelton08@h...>
        wrote:
        > > Maybe this is part of the Frahm situation? He has so few minutes
        > > and probably most of them are garbage time. Maybe his poorer play
        > > just happened during this time - and his better play happened the
        > > few minutes (percentage wise) that counted?
        >
        > Most people have made the opposite argument -- that Frahm's good
        > unadjusted plus-minus (+10.0 Roland Rating, almost twice that of
        any
        > other Sonics player save the four-minute effort of Leon Smith) is
        > largely due to him playing in garbage time and leading the Sonics
        on
        > runs along the lines of the 12/10 Boston game I mentioned
        previously
        > and the New Jersey game the night before.
        >
        > I was genuinely surprised to see Frahm rate so extraordinarily well
        > in DanVAL given the "clutch" adjustment.
        >
        > The Sonics simply have played well with Frahm in the game,
        > regardless the circumstances.

        I am not sure that true . .I think the cause and effect is when Frahm
        plays well (read shoots well) he get to stay in the game. When he
        doesn't shoot well . .the plays only a couple of minutes and sits. I
        think he probably has 8 or so good games that skew his results (not
        sure if skew is the right word, but indicate a greater value of his
        play than otherwise would be true).
      • Kevin Pelton
        Dan - The article is now live at Hoopsworld. Kevin
        Message 3 of 17 , May 3, 2004
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          Dan -

          The article is now live at Hoopsworld.

          Kevin
        • Kevin Pelton
          ... Well, obviously that message was supposed to only go to DanR, but I humbly think the column is worth pimping here anyway, especially since Stuart already
          Message 4 of 17 , May 3, 2004
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            > Dan -
            >
            > The article is now live at Hoopsworld.
            >
            > Kevin

            Well, obviously that message was supposed to only go to DanR, but I
            humbly think the column is worth pimping here anyway, especially
            since Stuart already hit on the Holy Grail metaphor:

            The latest from "Page 23" at Hoopsworld.com by Kevin Pelton:

            The Last NBA Crusade

            If you've seen the third and final Indiana Jones movie, "Indiana
            Jones and the Last Crusade", you probably recall what the hero
            encounters on his way to find the Holy Grail -- skulls and skeletons
            of those who have gone before him, also searching for the Holy Grail
            only to give their lives in the chase.

            Things aren't quite as dire when it comes to the search for the Holy
            Grail of rating systems by basketball's statistical analysts, but
            there are plenty of skeletons drying in the sun if you look through
            the history of such efforts.

            Over there is TENDEX, Doug Heeren's revolutionary first strike for
            using player statistics in a comprehensive rating form. Beside it
            lies Manley Credits, the simplification of TENDEX with no
            complicated pace factor to complicate, now resurrected as
            NBA.com's " Efficiency Rating System".

            Scattered throughout are other linear-weights formulas, with various
            values for blocks, steals, and whatever else. Squint hard enough and
            you might even find my own VORP system.

            None of these efforts, however, has succeeded in its quest to
            provide one rating system that's all we need to evaluate players.

            Dean Oliver, the author of Basketball on Paper, thinks there's a
            good reason for that -- the Holy Grail, at least the NBA version, is
            apocryphal, a myth blindly chased despite the fact that it does not
            exist.

            Oliver has won me over as a convert. No single rating system can
            ever provide enough subtlety, enough nuance, that it will be all we
            need. A balanced perspective, one that considers multiple rating
            systems as well as personal observation, is the only way to go.

            But that doesn't mean we can't make better rating systems. . . .

            Read the rest of the column:
            http://www.hoopsworld.com/article_8137.shtml
          • Daniel Dickey
            ... OK- cool - that makes sense. ... Count me as one that WOULD NOT complain about measuring garbage time. You obviously would have it weighted quite a bit
            Message 5 of 17 , May 5, 2004
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              >From: "dan_t_rosenbaum" <rosenbaum@...>
              >Reply-To: APBR_analysis@yahoogroups.com
              >To: APBR_analysis@yahoogroups.com
              >Subject: [APBR_analysis] Re: Major Update of WINVAL Ratings Through 2003-04
              >Date: Mon, 03 May 2004 02:42:40 -0000
              >
              >Dear DanD and JohnH:
              >
              >First of all, in comparing the game with an 11 point margin with 1
              >minute left in the third versus a game with a 4 point margin with 11
              >minutes left in the fourth, here is what my formula comes up with.
              >
              >11 point margin, 1 minute left in third: 9.0
              >4 point margin, 11 minutes left in fourth: 10.8

              OK- cool - that makes sense.

              >After I normalize the weights so that the average weight in the
              >fourth quarter is the same as the rest of the game, here is what I
              >end up with (with the average weight being 1).
              >
              >11 point margin, 1 minute left in third: 1.00
              >4 point margin, 11 minutes left in fourth: 1.29
              >
              >So I am counting latter situation much heavier.
              >
              >And on the matter of not counting garbage time at all. I could set
              >a minimum weight so that every observation is counted, but then I
              >suspect there are going to be a lot of people complain about me
              >measuring a bunch of garbage time phenoms. It is a bit of a no-win
              >situation.

              Count me as one that WOULD NOT complain about measuring garbage time. You
              obviously would have it weighted quite a bit less. PLUS you are already
              taking into account opposing lineups and other teamates on the court, etc.

              I do think we aren't getting a complete picture of a player that already has
              limited minutes to analyze when we ignore much of his performance (because
              he mainly is a "garbage time" player). So - I for one feel there should be
              a minimum small weight for garbage time.

              By the way - it looks like you might be weighting max clutch time at about
              twice the value of "normal" time- when it is all said and done - is this
              right? That kinda fits how I've envisioned looking at clutch performance -
              except I always thought the max having a weight of 2, normal 1, and
              "garbage" 0.5. Maybe 3, 1, and 0.33 would be even better. Who knows.

              Dan D

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            • tajallie@hotmail.com
              Dan, Having been one of the defenders of limiting the value of garbage time credit, count me as one who really doesn t care rather you have a zero value for
              Message 6 of 17 , May 5, 2004
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                Dan,

                Having been one of the defenders of limiting the value of garbage
                time credit, count me as one who really doesn't care rather you have
                a zero value for garbage time or some minimum value (in other words
                you wouldn't hear me screaming if you added a minimum value). While I
                agree there should probably be some value for performing well when
                you team is down by 25 pts in the fourth, the truth is that if you
                are performing well enough to matter, you will play more non-garbage
                minutes. . .I think it would be fine to give some value but I don't
                think it hurts to give none.

                Mike/Bob:

                Andre Miller this season

                Jump
                62% .376
                Close
                36% .607
                Dunk
                1% .800
                Tips
                1% .714
                Inside
                38% .612

                Last season

                Jump
                74% .369
                Close
                26% .557
                Dunk
                0% .667
                Tips
                0% .667
                Inside
                26% .560

                To me, this would seem to bear out that Denver does have better
                spacing and that playing with a very active big man like Camby,
                instead of low post player like Brand, along with a wing that often
                demands a double-team like 'Melo could easily be the reason for
                Miller's improvement. I suspect if you charted where he got his
                points from, you would find offensive rebounding due to 'Melo double
                teams and more focus on Camby, Nene resulted in more flexibity for
                Andre to crash the boards (rather than actual drives, in which case
                we would expect the close shots to maintain a 56% instead of
                improving to 61% although it could just be deviation noise).

                BTW: Despite the stats, I think it was a toss-up between
                Miller, 'Melo, and Camby for Denver's MVP as all three were clearly
                more important than everyone else. Basically against any good team,
                Denver needed to have two of those three play well to win.
                Furthermore, Miller is probably the best position / technical
                rebounder on the team (i.e. he understands when and where to crash
                the boards and how to box out better than any other Nugget . .I
                beleive those benefits are underated by both the stats and perception
                of value).
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