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Re: [APBR_analysis] Re: Assist tracking update  Dave Berri
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Plenty of papers available through...
http://www.csub.edu/~dberri/
Some abstracts and papers at
http://www.csub.edu/~dberri/research.html
i eventually found his homepage searching on david not dave....
his applications research page at:
http://www.csub.edu/~dberri/researchapps.html
has 3 links for 200203 NBA player rankings/studies but all appear to be inactive, so i could not review those for any comparison's to other work...
i see only one active article link at his research page (other than the abstract synopses), the one for the PDF "who is most valuable? measuring the player's production of wins in the NBA". the paper is a 1999 paper about the 9798 season, so i have not much to go on about berri's work other than this, and while i have had a number of stats courses i am not a stats major and thus don't understand all his work presented in the article because the derivations are not completely shown (hard to do in a published article)...
having said that, however, the article's conclusion says, quote "...how productive is each NBA player? the methods presented (here)....... provide an accurate answer to the question...... such evaluations can obviously be utilized with respect to free agent signings, playerforplayer trades, the allocation of minutes, and also to determine the impact changes in coaching methods or strategy have had on an individual's productivity...."
it goes on to say "...with respect to the academic literature the methods reported here are also likey to be useful. previous methods cited appear to have used the incorrect functional form, an incorrect set of data, and failed to account for the importance of team tempo. the correction of each of these shortcomings has led to an accurate appraisal of playing talent that can be utilized in the study of such issues as racial discrimination and worker remuneration under the auspices of differing institutional arrangements..."....
well that was a mouthful....
anyone know if any of his more current research is online for perusal, or if any of his work has been used by the league or any nba teams?...
 0 Attachment
 In APBR_analysis@yahoogroups.com, bchaikin@a... wrote:> having said that, however, the article's conclusion says,
quote "...how
> productive is each NBA player? the methods presented (here).......
provide an
> accurate answer to the question...... such evaluations can
obviously be utilized
> with respect to free agent signings, playerforplayer trades, the
allocation of
> minutes, and also to determine the impact changes in coaching
methods or
> strategy have had on an individual's productivity...."
methods
>
> it goes on to say "...with respect to the academic literature the
> reported here are also likey to be useful. previous methods cited
appear to have
> used the incorrect functional form, an incorrect set of data, and
failed to
> account for the importance of team tempo. the correction of each of
these
> shortcomings has led to an accurate appraisal of playing talent
that can be utilized
> in the study of such issues as racial discrimination and worker
remuneration
> under the auspices of differing institutional arrangements..."....
perusal, or if
>
> well that was a mouthful....
>
> anyone know if any of his more current research is online for
> any of his work has been used by the league or any nba teams?...
I get stuff from him every so often. I review a lot of sports econ
these days and he's doing almost all the basketball work. Journal of
Sports Economics doesn't appear to be online.
It was his recent work, which included a revision on that 1999 paper,
that we talked about a lot recently. Basically, his technique for
identifying the value of stats is a regression of team wins vs team
stats. He originally did it one way that had a bit of collinearity
issues, then redid it based upon a possessionsbased argument that I
made, and things worked out a little different. It was actually very
interesting if you look back on that 1999 paper online that his
regression pretty much pegs the possession formula. The coefficients
on FGA and TO are about 1. The coefficient on OR is about 1 and the
coefficient on FTA is about 0.4. So he was getting only marginal
performance above what teams would do with possessions. So he fixed
that. He recently did a paper in Journal of Sports Econ on the value
of a win in basketball  it's about $100K in gate revenue (in 1992
96) and about 56 times that for a playoff win. I think those
numbers double for today's money.
His stuff got used by the Sonics before they found my stuff in 2000.
They already used a kind of linear weights technique before and
that's all his really is.
I will add that Dave Berri is actually a very funny guy, funnier than
Dave Barry the columnist. His papers don't let that on. He is
pretty much known as the stand up comedian of econ.
Western Econ Association meeting this summer is in Vancouver, BC. I
will be going, as will Dave. No coincident SABR meeting this time.
DeanO
www.basketballonpaper.com 0 Attachment
Original Message
From: Dean Oliver [mailto:deano@...]
Sent: Tuesday, February 03, 2004 6:20 PM
[...]
>It was his recent work, which included a revision on that 1999 paper,
My recollection had been that when his work first came to the attention
>that we talked about a lot recently. Basically, his technique for
>identifying the value of stats is a regression of team wins vs team
>stats. He originally did it one way that had a bit of collinearity
of this group (I think it was then that we coined the term "laugh test"
with respect to his Rodman MVP result), that he had used a CobbDouglas
(i.e. loglinear) functional form. But I see in this online paper that
he says that linear is superior to loglinear, using, evidently,
MacKinnon, White, and Davidson's test.
My reaction would've been to use the BoxCox transformation, which is
specifically designed to find a bestfitting functional form from an
entire spectrum of possible functional forms (including the linear
and loglinear).
But, the MacKinnon, White, and Davidson paper is somewhat recent (1983),
whereas the BoxCox transformation dates back to 1964...I seem to remember
seeing an article several years ago about possible problems with the
BoxCox transformation (lack of consistent estimates when the null
hypothesis is not satisfied), so perhaps techniques such as MacKinnon,
White, and Davidson's have superseded it.
MKT 0 Attachment
One of the questions that Dave raises is this:
Why do all the linear weights techniques subtract off missed field
goals rather than all field goal attempts? Isn't any field goal
attempt a cost?
So I'd pose that to some of the people here. Why not subtract FGA
rather than (FGA  FGM)?
DeanO
www.basketballonpaper.com
 In APBR_analysis@yahoogroups.com, "Michael Tamada" <tamada@o...>
wrote:> Original Message
remember
> From: Dean Oliver [mailto:deano@r...]
> Sent: Tuesday, February 03, 2004 6:20 PM
>
> [...]
>
> >It was his recent work, which included a revision on that 1999 paper,
> >that we talked about a lot recently. Basically, his technique for
> >identifying the value of stats is a regression of team wins vs team
> >stats. He originally did it one way that had a bit of collinearity
>
> My recollection had been that when his work first came to the attention
> of this group (I think it was then that we coined the term "laugh test"
> with respect to his Rodman MVP result), that he had used a CobbDouglas
> (i.e. loglinear) functional form. But I see in this online paper that
> he says that linear is superior to loglinear, using, evidently,
> MacKinnon, White, and Davidson's test.
>
> My reaction would've been to use the BoxCox transformation, which is
> specifically designed to find a bestfitting functional form from an
> entire spectrum of possible functional forms (including the linear
> and loglinear).
>
> But, the MacKinnon, White, and Davidson paper is somewhat recent (1983),
> whereas the BoxCox transformation dates back to 1964...I seem to
> seeing an article several years ago about possible problems with the
> BoxCox transformation (lack of consistent estimates when the null
> hypothesis is not satisfied), so perhaps techniques such as MacKinnon,
> White, and Davidson's have superseded it.
>
>
> MKT 0 Attachment
I think he's right. It also has the nice effect of making 2 for 6
on 3's come out the same as 3 for 6 on 2's.
 In APBR_analysis@yahoogroups.com, "Dean Oliver" <deano@r...>
wrote:> One of the questions that Dave raises is this:
<tamada@o...>
>
> Why do all the linear weights techniques subtract off missed field
> goals rather than all field goal attempts? Isn't any field goal
> attempt a cost?
>
> So I'd pose that to some of the people here. Why not subtract FGA
> rather than (FGA  FGM)?
>
> DeanO
> www.basketballonpaper.com
>
>  In APBR_analysis@yahoogroups.com, "Michael Tamada"
> wrote:
paper,
> > Original Message
> > From: Dean Oliver [mailto:deano@r...]
> > Sent: Tuesday, February 03, 2004 6:20 PM
> >
> > [...]
> >
> > >It was his recent work, which included a revision on that 1999
> > >that we talked about a lot recently. Basically, his technique
for
> > >identifying the value of stats is a regression of team wins vs
team
> > >stats. He originally did it one way that had a bit of
collinearity
> >
attention
> > My recollection had been that when his work first came to the
> > of this group (I think it was then that we coined the
term "laugh test"
> > with respect to his Rodman MVP result), that he had used a Cobb
Douglas
> > (i.e. loglinear) functional form. But I see in this online
paper that
> > he says that linear is superior to loglinear, using, evidently,
which is
> > MacKinnon, White, and Davidson's test.
> >
> > My reaction would've been to use the BoxCox transformation,
> > specifically designed to find a bestfitting functional form
from an
> > entire spectrum of possible functional forms (including the
linear
> > and loglinear).
(1983),
> >
> > But, the MacKinnon, White, and Davidson paper is somewhat recent
> > whereas the BoxCox transformation dates back to 1964...I seem to
the
> remember
> > seeing an article several years ago about possible problems with
> > BoxCox transformation (lack of consistent estimates when the
null
> > hypothesis is not satisfied), so perhaps techniques such as
MacKinnon,
> > White, and Davidson's have superseded it.
> >
> >
> > MKT 0 Attachment
Original Message
From: Dean Oliver [mailto:deano@...]
Sent: Saturday, February 07, 2004 10:20 AM
>One of the questions that Dave raises is this:
I conjecture (but can't prove) that it's a question of what level of
>
>Why do all the linear weights techniques subtract off missed field
>goals rather than all field goal attempts? Isn't any field goal
>attempt a cost?
>
>So I'd pose that to some of the people here. Why not subtract FGA
>rather than (FGA  FGM)?
detail one wants to track things at. If we decide to track FGA, we're
noting that they put the team into a certain position, one which has
a couple of outcomes, namely FGM or FGMiss.
Or we can skip over that process and simply look at the outcome:
FGM or FGMiss. I.e. ignore the FGA.
I think it's analogous to the "possessions" vs "plays" question that
we periodically discuss here. Or equivalently, to this question:
Do we measure basketball teams' qualities in two areas, offense and
defense?
Or do we measure them in three areas: offense, defense, and
rebounding?
If we look as "possessionbased" stats, then the rebounds get folded
into the offense and defense measures. If we look at "playbased"
stats, then rebounding is a skill separate from offense and defense.
Neither technique is "correct" or "incorrect", it's a question of
at what level of detail, or with what "granularity" (to use a term
which seems to be one of the favorite overused buzzwords these days)
we want to study basketball.
Anyway, back to FGA. I think that's a choice that we can make. Just as
we can say that offensive rebounding is a part of offense, and defensive
rebounding a part of defense, we can say that FGA are a part of the FGM
and FGMiss stats. And hence can be ignored because they're already
"taken care of" by virtue of the trivial identity FGA == FGM + FGMiss.
But if we did want to study what happens where a team is before, and after,
if puts up its FGA, then we wouldn't want to ignore FGA.
An example from the interesting assist discussion we've been having: maybe
the value of the good passes (some but not all of which lead to measurable
assists) is that it permits the recipient to not only put up a FGA, but to
put one up with has an enhanced % probability of going in. Or it permits
the shooter to attempt a 3PT FGA, one which he otherwise wouldn't even
attempt to shoot because he's wellcovered (or doesn't even have the ball at
all, since we're assuming it was a good pass which got the ball to him).
Those I think are examples where FGA would matter and we wouldn't want to
sweep them under the rug by parroting the FGA == FGM+FGMiss identity.
To get to the original question, if we're using linear weights type
formulas, and have a choice of treating FGA as a negative or FGAFGMiss
as a negative, I think that's a case where it wouldn't make any difference.
An analogy: we can predict students GPAs by looking at their verbal SAT
and their math SAT, but if we wanted to we could instead use verbal SAT
and TOTAL SAT. And we'd get the same results, except for a factor to be
added to the coefficient on verbal SAT.
Aesthetically, the one problem with treating FGA as a negative as Berri
seems to want to is that they aren't by themselves a negative per se.
If they go in (FGM) they're part of a positive process; it's only if they
miss (FGMiss) that they become a part of a negative process.
Given the 24second clock, somebody has to shoot the ball at some point,
and it seems a bit severe to "call" a FGA a negative thing.
MKT 0 Attachment
 In APBR_analysis@yahoogroups.com, "Michael Tamada" <tamada@o...>
wrote:>... If they go in (FGM) they're part of a positive process; it's
only if they
> miss (FGMiss) that they become a part of a negative process.
point,
>
> Given the 24second clock, somebody has to shoot the ball at some
> and it seems a bit severe to "call" a FGA a negative thing.
The term used was "cost"; and yes, it costs you something to attempt
a shot. It also costs you gas money to drive to work.
Another term that comes to mind is "investment". Whether it's just
the time the ball is in its arc, or over the course of the game, you
reap the benefits of your shot's accuracy.
And when the clock is running down, almost Any shot is better than
no shot. You might get a foul; and there's about 1/3 chance of
getting the rebound (or somewhat less on a "forced" shot).
It seems any attempt to assign a negative factor to a FGA would
depend on the team's offensiverebounding strength; who's in the
lineup; and who's taking the shot; and ultimately, on a casebycase
basis.
I guess I don't use 'linear weights', since I don't subtract FGA, or
any multiple thereof. Rather, I multiply a scorer's rate by his
eff%. Is that the same thing? 0 Attachment
 In APBR_analysis@yahoogroups.com, "Mike G" <msg_53@h...> wrote:>  In APBR_analysis@yahoogroups.com, "Michael Tamada" <tamada@o...>
Here is Dave's rationale. If a shot goes in, it goes back to the
> wrote:
> >... If they go in (FGM) they're part of a positive process; it's
> only if they
> > miss (FGMiss) that they become a part of a negative process.
> >
> > Given the 24second clock, somebody has to shoot the ball at some
> point,
> > and it seems a bit severe to "call" a FGA a negative thing.
>
>
> The term used was "cost"; and yes, it costs you something to attempt
> a shot. It also costs you gas money to drive to work.
>
> Another term that comes to mind is "investment". Whether it's just
> the time the ball is in its arc, or over the course of the game, you
> reap the benefits of your shot's accuracy.
>
> And when the clock is running down, almost Any shot is better than
> no shot. You might get a foul; and there's about 1/3 chance of
> getting the rebound (or somewhat less on a "forced" shot).
>
> It seems any attempt to assign a negative factor to a FGA would
> depend on the team's offensiverebounding strength; who's in the
> lineup; and who's taking the shot; and ultimately, on a casebycase
> basis.
>
opponents. If a shot misses and doesn't get rebounded by the offense,
it goes back to the opponents. Given that we track offensive rebounds
and can count them separately, the cost of the shot is the same
whether it's made or missed. The return on the shot is already
reflected in whether points are scored.
Subtracting off missed shots rather than total shots does make a
difference in how players are evaluated. If you subtract off missed
fg and ft, you get a ranking of (using 1 as the coefficients)
Rank Player
1 Garnett,Kevin
2 O'Neal,Shaquille
3 Duncan,Tim
4 McGrady,Tracy
5 nowitzki,dirk
6 Bryant,Kobe
7 Webber,Chris
8 O'Neal,Jermaine
9 Sabonis,Arvydas
10 brand,elton
11 Kidd,Jason
12 Malone,Karl
13 ming,yao
14 gasol,pau
15 Bradley,Shawn
16 miller,brad
17 boozer,carlos
18 Pierce,Paul
19 Cassell,Sam
20 marion,shawn
21 Wallace,Ben
22 kirilenko,andrei
23 Marshall,Donyell
24 Nash,Steve
25 Stockton,John
26 Allen,Ray
27 Ilgauskas,Zydrun
28 randolph,zach
29 AbdurRahim,Shar
30 swift,stromile
If you subtract off just FGA and FTA, not misses, you get the ranking
on the right below (with the ranking above on the left):
Rank Player Rank Player
1 Garnett,Kevin 1 Wallace,Ben
2 O'Neal,Shaquille 2 Garnett,Kevin
3 Duncan,Tim 3 Bradley,Shawn
4 McGrady,Tracy 4 Duncan,Tim
5 nowitzki,dirk 5 Foyle,Adonal
6 Bryant,Kobe 6 Sabonis,Arvydas
7 Webber,Chris 7 Cato,Kelvin
8 O'Neal,Jermaine 8 boozer,carlos
9 Sabonis,Arvydas 9 Brown,P.J.
10 brand,elton 10 O'Neal,Shaquille
11 Kidd,Jason 11 Laettner,Christi
12 Malone,Karl 12 Grant,Brian
13 ming,yao 13 nowitzki,dirk
14 gasol,pau 14 Robinson,David
15 Bradley,Shawn 15 brand,elton
16 miller,brad 16 Stockton,John
17 boozer,carlos 17 Marshall,Donyell
18 Pierce,Paul 18 Ward,Charlie
19 Cassell,Sam 19 clark,keon
20 marion,shawn 20 Battie,Tony
21 Wallace,Ben 21 Kidd,Jason
22 kirilenko,andrei 22 Divac,Vlade
23 Marshall,Donyell 23 miller,brad
24 Nash,Steve 24 ming,yao
25 Stockton,John 25 marion,shawn
26 Allen,Ray 26 lafrentz,raef
27 Ilgauskas,Zydrun 27 murphy,troy
28 randolph,zach 28 bradley,michael
29 AbdurRahim,Shar 29 Weatherspoon,Cla
30 swift,stromile 30 Webber,Chris
Basically, guards get killed by using just FGA and FTA.
>
I did not know this. I guess Kevin P also does something like this.
> I guess I don't use 'linear weights', since I don't subtract FGA, or
> any multiple thereof. Rather, I multiply a scorer's rate by his
> eff%. Is that the same thing?
The form I've typically seen is (and the form used above)
pts + reb + ast + stl + blk  tov  missedFT  missed FG
I thought that this was what MikeG and a few others were doing. I
know that Bob Bellotti, Dave Heeren, John H, and a bunch of others use
a form like this.
So you multiply PTS/min by an effective shooting percentage (including
free throws)? How does this get combined with reb, ast, etc.?
DeanO
www.basketballonpaper.com 0 Attachment
> I did not know this. I guess Kevin P also does something like
I basically start with the formula for true shooting percentage (or
> this. The form I've typically seen is (and the form used above)
>
> pts + reb + ast + stl + blk  tov  missedFT  missed FG
>
> I thought that this was what MikeG and a few others were doing. I
> know that Bob Bellotti, Dave Heeren, John H, and a bunch of others
> use a form like this.
>
> So you multiply PTS/min by an effective shooting percentage
> including free throws)? How does this get combined with reb, ast,
> etc.?
whatever you want to call it)  PTS/(FGA+(.44*FTA))  and add the
other positives (REB, AST, STL, BLK) to the numerator and
other "opportunities"  minutes and turnovers, plus part of
the "positives" to keep nonshooters from being overrated  to the
denominator.
I don't think I've ever seen anyone who does it quite the way I do,
though MikeG's appears to be in the same spirit, more or less.
As far as the FGM/FGA argument, I look at it this way: Would you
ever evaluate a player's offensive efficiency by looking just at
missed field goals, not at attempts? Of course not. You look at
PTS/POS, not PTS/MissPOS. So why should linear weights treat that
any differently?
(You'd have to use something like 1/2 for the coefficient of FGA and
FTA, though, wouldn't you? Isn't that why DeanO's rankings change so
much?)
How you treat offensive rebounds does affect things. I think DeanO
and JohnH both have the value of a missed field goal as something
less than one possession to account for offensive rebounds. Since I
treat offensive rebounding as a separate category in my nonlinear
weights work, I don't. 0 Attachment
The problem here is with the coefficient. Any choice is somewhat
arbitrary, but using one is pretty bad. You'll get a much more
reasonable list if you use a coefficient that will roughly
approximate the list you get substracting field goal misses.
Something like .5*(fga +.45*fta).
 In APBR_analysis@yahoogroups.com, "Dean Oliver" <deano@r...>
wrote:>  In APBR_analysis@yahoogroups.com, "Mike G" <msg_53@h...> wrote:
<tamada@o...>
> >  In APBR_analysis@yahoogroups.com, "Michael Tamada"
> > wrote:
it's
> > >... If they go in (FGM) they're part of a positive process;
> > only if they
some
> > > miss (FGMiss) that they become a part of a negative process.
> > >
> > > Given the 24second clock, somebody has to shoot the ball at
> > point,
attempt
> > > and it seems a bit severe to "call" a FGA a negative thing.
> >
> >
> > The term used was "cost"; and yes, it costs you something to
> > a shot. It also costs you gas money to drive to work.
just
> >
> > Another term that comes to mind is "investment". Whether it's
> > the time the ball is in its arc, or over the course of the game,
you
> > reap the benefits of your shot's accuracy.
than
> >
> > And when the clock is running down, almost Any shot is better
> > no shot. You might get a foul; and there's about 1/3 chance of
case
> > getting the rebound (or somewhat less on a "forced" shot).
> >
> > It seems any attempt to assign a negative factor to a FGA would
> > depend on the team's offensiverebounding strength; who's in the
> > lineup; and who's taking the shot; and ultimately, on a caseby
> > basis.
offense,
> >
>
> Here is Dave's rationale. If a shot goes in, it goes back to the
> opponents. If a shot misses and doesn't get rebounded by the
> it goes back to the opponents. Given that we track offensive
rebounds
> and can count them separately, the cost of the shot is the same
missed
> whether it's made or missed. The return on the shot is already
> reflected in whether points are scored.
>
> Subtracting off missed shots rather than total shots does make a
> difference in how players are evaluated. If you subtract off
> fg and ft, you get a ranking of (using 1 as the coefficients)
ranking
>
> Rank Player
> 1 Garnett,Kevin
> 2 O'Neal,Shaquille
> 3 Duncan,Tim
> 4 McGrady,Tracy
> 5 nowitzki,dirk
> 6 Bryant,Kobe
> 7 Webber,Chris
> 8 O'Neal,Jermaine
> 9 Sabonis,Arvydas
> 10 brand,elton
> 11 Kidd,Jason
> 12 Malone,Karl
> 13 ming,yao
> 14 gasol,pau
> 15 Bradley,Shawn
> 16 miller,brad
> 17 boozer,carlos
> 18 Pierce,Paul
> 19 Cassell,Sam
> 20 marion,shawn
> 21 Wallace,Ben
> 22 kirilenko,andrei
> 23 Marshall,Donyell
> 24 Nash,Steve
> 25 Stockton,John
> 26 Allen,Ray
> 27 Ilgauskas,Zydrun
> 28 randolph,zach
> 29 AbdurRahim,Shar
> 30 swift,stromile
>
> If you subtract off just FGA and FTA, not misses, you get the
> on the right below (with the ranking above on the left):
FGA, or
>
> Rank Player Rank Player
> 1 Garnett,Kevin 1 Wallace,Ben
> 2 O'Neal,Shaquille 2 Garnett,Kevin
> 3 Duncan,Tim 3 Bradley,Shawn
> 4 McGrady,Tracy 4 Duncan,Tim
> 5 nowitzki,dirk 5 Foyle,Adonal
> 6 Bryant,Kobe 6 Sabonis,Arvydas
> 7 Webber,Chris 7 Cato,Kelvin
> 8 O'Neal,Jermaine 8 boozer,carlos
> 9 Sabonis,Arvydas 9 Brown,P.J.
> 10 brand,elton 10 O'Neal,Shaquille
> 11 Kidd,Jason 11 Laettner,Christi
> 12 Malone,Karl 12 Grant,Brian
> 13 ming,yao 13 nowitzki,dirk
> 14 gasol,pau 14 Robinson,David
> 15 Bradley,Shawn 15 brand,elton
> 16 miller,brad 16 Stockton,John
> 17 boozer,carlos 17 Marshall,Donyell
> 18 Pierce,Paul 18 Ward,Charlie
> 19 Cassell,Sam 19 clark,keon
> 20 marion,shawn 20 Battie,Tony
> 21 Wallace,Ben 21 Kidd,Jason
> 22 kirilenko,andrei 22 Divac,Vlade
> 23 Marshall,Donyell 23 miller,brad
> 24 Nash,Steve 24 ming,yao
> 25 Stockton,John 25 marion,shawn
> 26 Allen,Ray 26 lafrentz,raef
> 27 Ilgauskas,Zydrun 27 murphy,troy
> 28 randolph,zach 28 bradley,michael
> 29 AbdurRahim,Shar 29 Weatherspoon,Cla
> 30 swift,stromile 30 Webber,Chris
>
> Basically, guards get killed by using just FGA and FTA.
>
> >
> > I guess I don't use 'linear weights', since I don't subtract
> > any multiple thereof. Rather, I multiply a scorer's rate by his
this.
> > eff%. Is that the same thing?
>
> I did not know this. I guess Kevin P also does something like
> The form I've typically seen is (and the form used above)
use
>
> pts + reb + ast + stl + blk  tov  missedFT  missed FG
>
> I thought that this was what MikeG and a few others were doing. I
> know that Bob Bellotti, Dave Heeren, John H, and a bunch of others
> a form like this.
(including
>
> So you multiply PTS/min by an effective shooting percentage
> free throws)? How does this get combined with reb, ast, etc.?
>
> DeanO
> www.basketballonpaper.com 0 Attachment
 In APBR_analysis@yahoogroups.com, "Dean Oliver" <deano@r...>
wrote:>
ranking
> If you subtract off just FGA and FTA, not misses, you get the
> on the right below (with the ranking above on the left):
These rankings are both wack. The one on the right is the same one,
>
> Rank Player Rank Player
> 1 Garnett,Kevin 1 Wallace,Ben
> 2 O'Neal,Shaquille 2 Garnett,Kevin
> 3 Duncan,Tim 3 Bradley,Shawn
> 4 McGrady,Tracy 4 Duncan,Tim
> 5 nowitzki,dirk 5 Foyle,Adonal
> 6 Bryant,Kobe 6 Sabonis,Arvydas
> 7 Webber,Chris 7 Cato,Kelvin
> 8 O'Neal,Jermaine 8 boozer,carlos
> 9 Sabonis,Arvydas 9 Brown,P.J.
> 10 brand,elton 10 O'Neal,Shaquille
> 11 Kidd,Jason 11 Laettner,Christi
> 12 Malone,Karl 12 Grant,Brian
> 13 ming,yao 13 nowitzki,dirk
> 14 gasol,pau 14 Robinson,David
> 15 Bradley,Shawn 15 brand,elton
> 16 miller,brad 16 Stockton,John
> 17 boozer,carlos 17 Marshall,Donyell
> 18 Pierce,Paul 18 Ward,Charlie
> 19 Cassell,Sam 19 clark,keon
> 20 marion,shawn 20 Battie,Tony
> 21 Wallace,Ben 21 Kidd,Jason
> 22 kirilenko,andrei 22 Divac,Vlade
> 23 Marshall,Donyell 23 miller,brad
> 24 Nash,Steve 24 ming,yao
> 25 Stockton,John 25 marion,shawn
> 26 Allen,Ray 26 lafrentz,raef
> 27 Ilgauskas,Zydrun 27 murphy,troy
> 28 randolph,zach 28 bradley,michael
> 29 AbdurRahim,Shar 29 Weatherspoon,Cla
> 30 swift,stromile 30 Webber,Chris
>
> Basically, guards get killed by using just FGA and FTA.
apparently, that had Rodman at the top. Now it's Ben, Bradley, and
Foyle, over Shaq.
I guess, too, it's last year's numbers.
The left list isn't as bad, but still has Bradley at #15.
> The form I've typically seen is (and the form used above)
doing. ...> So you multiply PTS/min by an effective shooting
>
> pts + reb + ast + stl + blk  tov  missedFT  missed FG
>
> I thought that this was what MikeG and a few others were
percentage (including> free throws)? How does this get combined with reb, ast, etc.?
I don't add and subtract totals, I add and subtract "rates", which
are tweaked by team scoring/rebounding rates.
The adjustment due to eff% is relative to a standard that does not
change over time. This is a debatable practice, but my philosophy
is that one is responsible for one's shot. So 60% is 60%, and 40%
is 40%. Some player's eff% is very contextdependent, while others
take their shooting with them when they move.
I used to take a player's scoring rate and multiply it by eff%/.527
(where .527 is the arbitrary average I started with, in the '80s).
But I got tired of seeing the high% teams being overrated. So now
I split the difference.
For example, Shareef AbdurRahim is shooting .566 eff%. With my
older system, I'd have multiplied his 21.5 pts/36 min by .566/.527,
to get 23.1 for his scoring rate.
Now I multipley 21.5 by ((.566+.527)/2)/.527 , for a 22.3 rate.
Basically, I've reduced by half, the effect of a higher or lower
thanaverage shooting %.
I still don't get team rates that summarize team success. Good
defensive teams are still undervalued in my system. Maybe team
defense isn't a function of individual ability. 0 Attachment
 In APBR_analysis@yahoogroups.com, "Mike G" <msg_53@h...> wrote:>  In APBR_analysis@yahoogroups.com, "Dean Oliver" <deano@r...>
Note that those were per minute Martin Manley credit things. The per
> wrote:
> >
> > If you subtract off just FGA and FTA, not misses, you get the
> ranking
> > on the right below (with the ranking above on the left):
> >
> > Rank Player Rank Player
> > 1 Garnett,Kevin 1 Wallace,Ben
> > 2 O'Neal,Shaquille 2 Garnett,Kevin
>
> These rankings are both wack. The one on the right is the same one,
> apparently, that had Rodman at the top. Now it's Ben, Bradley, and
> Foyle, over Shaq.
>
minute stuff and variations on weights can change things. I just use
these to make a point about how different things become if you
subtract off FGA rather than FG misses.
The one on the right is not the same as the one that had Rodman on
top, but it is based on the same principal: that each field goal
attempt has the same cost. That's what Dave Berri is saying.
>
Per minute rates? Rates of? (See below)
> > The form I've typically seen is (and the form used above)
> >
> > pts + reb + ast + stl + blk  tov  missedFT  missed FG
> >
> > I thought that this was what MikeG and a few others were
> doing. ...> So you multiply PTS/min by an effective shooting
> percentage (including
> > free throws)? How does this get combined with reb, ast, etc.?
>
> I don't add and subtract totals, I add and subtract "rates", which
> are tweaked by team scoring/rebounding rates.
>
Do you do something similar for assists, rebs, etc.?
> The adjustment due to eff% is relative to a standard that does not
> change over time. This is a debatable practice, but my philosophy
> is that one is responsible for one's shot. So 60% is 60%, and 40%
> is 40%. Some player's eff% is very contextdependent, while others
> take their shooting with them when they move.
>
> I used to take a player's scoring rate and multiply it by eff%/.527
> (where .527 is the arbitrary average I started with, in the '80s).
> But I got tired of seeing the high% teams being overrated. So now
> I split the difference.
>
> For example, Shareef AbdurRahim is shooting .566 eff%. With my
> older system, I'd have multiplied his 21.5 pts/36 min by .566/.527,
> to get 23.1 for his scoring rate.
>
> Now I multipley 21.5 by ((.566+.527)/2)/.527 , for a 22.3 rate.
>
>
Team defense is definitely something that involves more than
> I still don't get team rates that summarize team success. Good
> defensive teams are still undervalued in my system. Maybe team
> defense isn't a function of individual ability.
individual ability. A coach determines where players go in that D.
That coach can do that in such a way that it doesn't take best
advantage of player ability. Ludicrous example: Man to man defense
with Tim Duncan guarding the opposing point guard and Tony Parker
guarding a center. More realistic example: Dallas Mavericks playing
straight man D with no help (which they don't do).
But, despite the fact that team defense is a function of choices, what
we are all measuring is performance  what players do. The players
implement what a coach says. If a measurement is still missing good
defensive teams, it's missing part of performance and missing part of
what we'd like to predict.
DeanO
www.basketballonpaper.com
"Oliver goes beyond stats to dissect what it takes to win. His breezy
style makes for enjoyable reading, but there are plenty of points of
wisdom as well. This book can be appreciated by fans, players,
coaches and executives, but more importantly it can be used as a text
book for all these groups. You are sure to learn something you didn't
know about basketball here." Pete Palmer, coauthor, Hidden Game of
Baseball and Hidden Game of Football 0 Attachment
I think this gets to one of the weaknesses of Berri's system, and how
he ended up with Rodman as the top player in his original study.
This whole time, he's been calculating the MARGINAL value of made
shots, but the ABSOLUTE value of rebounds, steals, turnovers and
blocks, which has tended to massively overrate big men in general and
the Rodman/Wallace types in particular.
 In APBR_analysis@yahoogroups.com, "Dean Oliver" <deano@r...>
wrote:> One of the questions that Dave raises is this:
paper,
>
> Why do all the linear weights techniques subtract off missed field
> goals rather than all field goal attempts? Isn't any field goal
> attempt a cost?
>
> So I'd pose that to some of the people here. Why not subtract FGA
> rather than (FGA  FGM)?
>
> DeanO
> www.basketballonpaper.com
>
>  In APBR_analysis@yahoogroups.com, "Michael Tamada" <tamada@o...>
> wrote:
> > Original Message
> > From: Dean Oliver [mailto:deano@r...]
> > Sent: Tuesday, February 03, 2004 6:20 PM
> >
> > [...]
> >
> > >It was his recent work, which included a revision on that 1999
> > >that we talked about a lot recently. Basically, his technique
for
> > >identifying the value of stats is a regression of team wins vs
team
> > >stats. He originally did it one way that had a bit of
collinearity
> >
attention
> > My recollection had been that when his work first came to the
> > of this group (I think it was then that we coined the term "laugh
test"
> > with respect to his Rodman MVP result), that he had used a Cobb
Douglas
> > (i.e. loglinear) functional form. But I see in this online paper
that
> > he says that linear is superior to loglinear, using, evidently,
which is
> > MacKinnon, White, and Davidson's test.
> >
> > My reaction would've been to use the BoxCox transformation,
> > specifically designed to find a bestfitting functional form from
an
> > entire spectrum of possible functional forms (including the linear
(1983),
> > and loglinear).
> >
> > But, the MacKinnon, White, and Davidson paper is somewhat recent
> > whereas the BoxCox transformation dates back to 1964...I seem to
the
> remember
> > seeing an article several years ago about possible problems with
> > BoxCox transformation (lack of consistent estimates when the
null
> > hypothesis is not satisfied), so perhaps techniques such as
MacKinnon,
> > White, and Davidson's have superseded it.
> >
> >
> > MKT 0 Attachment
But in reality those two aren't equivalent. I'd rather go 2 for 6 on
3s, because I have an extra chance at an offensive rebound.
 In APBR_analysis@yahoogroups.com, "wimpds" <wimpds@y...> wrote:
> I think he's right. It also has the nice effect of making 2 for 6
> on 3's come out the same as 3 for 6 on 2's.
>
>
>
>  In APBR_analysis@yahoogroups.com, "Dean Oliver" <deano@r...>
> wrote:
> > One of the questions that Dave raises is this:
> >
> > Why do all the linear weights techniques subtract off missed field
> > goals rather than all field goal attempts? Isn't any field goal
> > attempt a cost?
> >
> > So I'd pose that to some of the people here. Why not subtract FGA
> > rather than (FGA  FGM)?
> >
> > DeanO
> > www.basketballonpaper.com
> >
> >  In APBR_analysis@yahoogroups.com, "Michael Tamada"
> <tamada@o...>
> > wrote:
> > > Original Message
> > > From: Dean Oliver [mailto:deano@r...]
> > > Sent: Tuesday, February 03, 2004 6:20 PM
> > >
> > > [...]
> > >
> > > >It was his recent work, which included a revision on that 1999
> paper,
> > > >that we talked about a lot recently. Basically, his technique
> for
> > > >identifying the value of stats is a regression of team wins vs
> team
> > > >stats. He originally did it one way that had a bit of
> collinearity
> > >
> > > My recollection had been that when his work first came to the
> attention
> > > of this group (I think it was then that we coined the
> term "laugh test"
> > > with respect to his Rodman MVP result), that he had used a Cobb
> Douglas
> > > (i.e. loglinear) functional form. But I see in this online
> paper that
> > > he says that linear is superior to loglinear, using, evidently,
> > > MacKinnon, White, and Davidson's test.
> > >
> > > My reaction would've been to use the BoxCox transformation,
> which is
> > > specifically designed to find a bestfitting functional form
> from an
> > > entire spectrum of possible functional forms (including the
> linear
> > > and loglinear).
> > >
> > > But, the MacKinnon, White, and Davidson paper is somewhat
recent
> (1983),
> > > whereas the BoxCox transformation dates back to 1964...I seem
to
> > remember
> > > seeing an article several years ago about possible problems
with
> the
> > > BoxCox transformation (lack of consistent estimates when the
> null
> > > hypothesis is not satisfied), so perhaps techniques such as
> MacKinnon,
> > > White, and Davidson's have superseded it.
> > >
> > >
> > > MKT 0 Attachment
But that just amplifies my point. If you subtract FGmisses then
you're giving an advantage to the guy who goes 36 on twos. (Of
course if you choose a certain coefficient then you're basically
taking scoring out of the equation entirely.)
 In APBR_analysis@yahoogroups.com, "John Hollinger"
<alleyoop2@y...> wrote:> But in reality those two aren't equivalent. I'd rather go 2 for 6
on
> 3s, because I have an extra chance at an offensive rebound.
6
>
>  In APBR_analysis@yahoogroups.com, "wimpds" <wimpds@y...> wrote:
> > I think he's right. It also has the nice effect of making 2 for
> > on 3's come out the same as 3 for 6 on 2's.
field
> >
> >
> >
> >  In APBR_analysis@yahoogroups.com, "Dean Oliver" <deano@r...>
> > wrote:
> > > One of the questions that Dave raises is this:
> > >
> > > Why do all the linear weights techniques subtract off missed
> > > goals rather than all field goal attempts? Isn't any field
goal
> > > attempt a cost?
FGA
> > >
> > > So I'd pose that to some of the people here. Why not subtract
> > > rather than (FGA  FGM)?
1999
> > >
> > > DeanO
> > > www.basketballonpaper.com
> > >
> > >  In APBR_analysis@yahoogroups.com, "Michael Tamada"
> > <tamada@o...>
> > > wrote:
> > > > Original Message
> > > > From: Dean Oliver [mailto:deano@r...]
> > > > Sent: Tuesday, February 03, 2004 6:20 PM
> > > >
> > > > [...]
> > > >
> > > > >It was his recent work, which included a revision on that
> > paper,
technique
> > > > >that we talked about a lot recently. Basically, his
> > for
vs
> > > > >identifying the value of stats is a regression of team wins
> > team
the
> > > > >stats. He originally did it one way that had a bit of
> > collinearity
> > > >
> > > > My recollection had been that when his work first came to
> > attention
Cobb
> > > > of this group (I think it was then that we coined the
> > term "laugh test"
> > > > with respect to his Rodman MVP result), that he had used a
> > Douglas
evidently,
> > > > (i.e. loglinear) functional form. But I see in this online
> > paper that
> > > > he says that linear is superior to loglinear, using,
> > > > MacKinnon, White, and Davidson's test.
seem
> > > >
> > > > My reaction would've been to use the BoxCox transformation,
> > which is
> > > > specifically designed to find a bestfitting functional form
> > from an
> > > > entire spectrum of possible functional forms (including the
> > linear
> > > > and loglinear).
> > > >
> > > > But, the MacKinnon, White, and Davidson paper is somewhat
> recent
> > (1983),
> > > > whereas the BoxCox transformation dates back to 1964...I
> to
the
> > > remember
> > > > seeing an article several years ago about possible problems
> with
> > the
> > > > BoxCox transformation (lack of consistent estimates when
> > null
> > > > hypothesis is not satisfied), so perhaps techniques such as
> > MacKinnon,
> > > > White, and Davidson's have superseded it.
> > > >
> > > >
> > > > MKT 0 Attachment
I disagree with the way most linear weight equations currently value
field goals. In my opinion, a field goal should be worth :
FG = Points Scored  Opponent Pts Per Possession
Basically, with any basket a team makes, the team is getting points
and a turnover. A turnover is worth the "Opponent Pts Per
Possession" and that is subtracted from the points scored by the
field goal to get the overall value of the made basket.
So if we take the "Opponent Pts Per Possession" to be 1, then a 2ptr
is worth 1 and a 3ptr is worth 2.
As an illustration, we can look at the effect of making 2/6 three
pointers versus 3/6 two pointers. First, let us give the value of a
FG Miss as follows:
FG Miss =  Opponent Rebound% x Opponent Pts Per Possession
And since the average defensive rebound percentage is roughly 66%,
I'll take a FG Miss to be worth 2/3.
Then, making 2/6 treys would give us:
2 + 2  2/3  2/3  2/3  2/3 = 1.33
Making 3/6 2ptrs would give us:
1 + 1 + 1  2/3  2/3  2/3 = 1
The 2/6 treys are worth more because, as mentioned before, they give
us an extra offensive rebounding opportunity which is worth about
1/3 of a point.
Currently, linear weight equations have the form of PTSFGM... but
taking into account the above, the equations would have the form of
PTSFGA+FGM... where, strangely, we would add some value for each
miss, while subtracting some value for each attempt (i.e. 1*PTS 
1*FGA + 1/3*FGM)
Jim Tang
 In APBR_analysis@yahoogroups.com, "wimpds" <wimpds@y...> wrote:
> But that just amplifies my point. If you subtract FGmisses then
> you're giving an advantage to the guy who goes 36 on twos. (Of
> course if you choose a certain coefficient then you're basically
> taking scoring out of the equation entirely.)
>
>  In APBR_analysis@yahoogroups.com, "John Hollinger"
> <alleyoop2@y...> wrote:
> > But in reality those two aren't equivalent. I'd rather go 2 for
6
> on
> > 3s, because I have an extra chance at an offensive rebound.
> > 0 Attachment
 In APBR_analysis@yahoogroups.com, "John Hollinger"
<alleyoop2@y...> wrote:> But in reality those two aren't equivalent. I'd rather go 2 for 6 on
And if were playing you *I'd* rather you go 2 for 6 on 3's,
> 3s, because I have an extra chance at an offensive rebound.
becaue I have a 2 out of 3 chance of getting that extra
rebound instead of you..
:)
>
>  In APBR_analysis@yahoogroups.com, "wimpds" <wimpds@y...> wrote:
> > I think he's right. It also has the nice effect of making 2 for 6
> > on 3's come out the same as 3 for 6 on 2's.
> >
> >
> >
> >  In APBR_analysis@yahoogroups.com, "Dean Oliver" <deano@r...>
> > wrote:
> > > One of the questions that Dave raises is this:
> > >
> > > Why do all the linear weights techniques subtract off missed field
> > > goals rather than all field goal attempts? Isn't any field goal
> > > attempt a cost?
> > >
> > > So I'd pose that to some of the people here. Why not subtract FGA
> > > rather than (FGA  FGM)?
> > >
> > > DeanO
> > > www.basketballonpaper.com
> > >
> > >  In APBR_analysis@yahoogroups.com, "Michael Tamada"
> > <tamada@o...>
> > > wrote:
> > > > Original Message
> > > > From: Dean Oliver [mailto:deano@r...]
> > > > Sent: Tuesday, February 03, 2004 6:20 PM
> > > >
> > > > [...]
> > > >
> > > > >It was his recent work, which included a revision on that 1999
> > paper,
> > > > >that we talked about a lot recently. Basically, his technique
> > for
> > > > >identifying the value of stats is a regression of team wins vs
> > team
> > > > >stats. He originally did it one way that had a bit of
> > collinearity
> > > >
> > > > My recollection had been that when his work first came to the
> > attention
> > > > of this group (I think it was then that we coined the
> > term "laugh test"
> > > > with respect to his Rodman MVP result), that he had used a Cobb
> > Douglas
> > > > (i.e. loglinear) functional form. But I see in this online
> > paper that
> > > > he says that linear is superior to loglinear, using, evidently,
> > > > MacKinnon, White, and Davidson's test.
> > > >
> > > > My reaction would've been to use the BoxCox transformation,
> > which is
> > > > specifically designed to find a bestfitting functional form
> > from an
> > > > entire spectrum of possible functional forms (including the
> > linear
> > > > and loglinear).
> > > >
> > > > But, the MacKinnon, White, and Davidson paper is somewhat
> recent
> > (1983),
> > > > whereas the BoxCox transformation dates back to 1964...I seem
> to
> > > remember
> > > > seeing an article several years ago about possible problems
> with
> > the
> > > > BoxCox transformation (lack of consistent estimates when the
> > null
> > > > hypothesis is not satisfied), so perhaps techniques such as
> > MacKinnon,
> > > > White, and Davidson's have superseded it.
> > > >
> > > >
> > > > MKT 0 Attachment
I see the smiley, but disregarding it ...
The problem with this reasoning is that I'd rather have you
have a 2 out of 3 chance of getting the rebound than have
a *100%* chance of getting the ball  which is what happens
every time I make a field goal. If I go 26 on 3pointers
I've given you the ball only twice; if I go 36 on 2pointers
I've given you the ball three times.
Jim Tang's recent posting is exactly right: each made field
goal is accompanied by the equivalent of a turnover. Because
the opponent gets the ball, guaranteed. Missed field goals
do not give the opponent the ball; he has to fight for it,
with only a 2/3 chance of winning.
(Of course the problem with missed FGs is that they give you
0 points, whereas made FGs give you 2 or 3 points.)
MKT
Original Message
From: Charlie Board [mailto:cboard@...]
Sent: Wednesday, February 11, 2004 10:59 AM
 In APBR_analysis@yahoogroups.com, "John Hollinger"
<alleyoop2@y...> wrote:> But in reality those two aren't equivalent. I'd rather go 2 for 6 on
And if were playing you *I'd* rather you go 2 for 6 on 3's,
> 3s, because I have an extra chance at an offensive rebound.
becaue I have a 2 out of 3 chance of getting that extra
rebound instead of you..
:)
>
Yahoo! Groups Links
>  In APBR_analysis@yahoogroups.com, "wimpds" <wimpds@y...> wrote:
> > I think he's right. It also has the nice effect of making 2 for 6
> > on 3's come out the same as 3 for 6 on 2's.
> >
> >
> >
> >  In APBR_analysis@yahoogroups.com, "Dean Oliver" <deano@r...>
> > wrote:
> > > One of the questions that Dave raises is this:
> > >
> > > Why do all the linear weights techniques subtract off missed field
> > > goals rather than all field goal attempts? Isn't any field goal
> > > attempt a cost?
> > >
> > > So I'd pose that to some of the people here. Why not subtract FGA
> > > rather than (FGA  FGM)?
> > >
> > > DeanO
> > > www.basketballonpaper.com
> > >
> > >  In APBR_analysis@yahoogroups.com, "Michael Tamada"
> > <tamada@o...>
> > > wrote:
> > > > Original Message
> > > > From: Dean Oliver [mailto:deano@r...]
> > > > Sent: Tuesday, February 03, 2004 6:20 PM
> > > >
> > > > [...]
> > > >
> > > > >It was his recent work, which included a revision on that 1999
> > paper,
> > > > >that we talked about a lot recently. Basically, his technique
> > for
> > > > >identifying the value of stats is a regression of team wins vs
> > team
> > > > >stats. He originally did it one way that had a bit of
> > collinearity
> > > >
> > > > My recollection had been that when his work first came to the
> > attention
> > > > of this group (I think it was then that we coined the
> > term "laugh test"
> > > > with respect to his Rodman MVP result), that he had used a Cobb
> > Douglas
> > > > (i.e. loglinear) functional form. But I see in this online
> > paper that
> > > > he says that linear is superior to loglinear, using, evidently,
> > > > MacKinnon, White, and Davidson's test.
> > > >
> > > > My reaction would've been to use the BoxCox transformation,
> > which is
> > > > specifically designed to find a bestfitting functional form
> > from an
> > > > entire spectrum of possible functional forms (including the
> > linear
> > > > and loglinear).
> > > >
> > > > But, the MacKinnon, White, and Davidson paper is somewhat
> recent
> > (1983),
> > > > whereas the BoxCox transformation dates back to 1964...I seem
> to
> > > remember
> > > > seeing an article several years ago about possible problems
> with
> > the
> > > > BoxCox transformation (lack of consistent estimates when the
> > null
> > > > hypothesis is not satisfied), so perhaps techniques such as
> > MacKinnon,
> > > > White, and Davidson's have superseded it.
> > > >
> > > >
> > > > MKT
 0 Attachment
> Jim Tang's recent posting is exactly right: each made field
I wouldn't say _exactly_ right. There's no reason opponent points per
> goal is accompanied by the equivalent of a turnover. Because
> the opponent gets the ball, guaranteed. Missed field goals
> do not give the opponent the ball; he has to fight for it,
> with only a 2/3 chance of winning.
possession should enter the equation, because the opponents are
getting the same number of possessions regardless of whether the
offense makes the shot or misses it.
What's being affected is the team's own "minor possessions"
or "plays"  it's getting extra shots at the basket because it's
rebounding more of its own shots.
So the relevant equeation would be PTS  FGA + (FGAFGM)*OREB%*ORTG
(based on plays).
The added value of missed shots, above and beyond turnovers, is given
by the team's offensive rebound percentage times its points per
possession.
Of course, this assumes that an offensive rebound "play" is just as
valuable as a normal "play". In fact, most research seems to indicate
that it's more valuable. (Right?)
There also needs to be an adjustment made for missed free throws,
half of which, similarly, have a chance of being rebounded by the
offensive team. 0 Attachment
There may be other ways to derive the value of a field goal, but by
my method, "opponents pts per possession" (OPPP) is essential. In
fact, your own pts per possession is not needed at all.
The idea is to measure how each event affects your net points by the
time you regain possession. So if you give up a turnover, you can
expect you to have 1 net points when you get the ball back
(assuming your opponent scores on average 1 pt per poss). If you
miss a shot, you can expect to have 2/3 net points when you get the
ball back (assuming your opponent's defensive rebound pct is 66%).
If you make a 2pt shot, then you can expect have +1 net points when
you get the ball back (since you scored 2pts and your opponent will
score 1 pt on average).
By possession, I mean everything that happens between your opponent
gaining possession and you regaining it. So OPPP already takes into
account factors based on plays or "minor possessions". Of course,
OPPP is also dependent on your own ability on the defensive end and
dependent on the situation (ie following a steal), but the point is
that all that stuff can be reduced to one figure.
It's true that your opponent gets the ball back regardless of
whether your shot is made or missed, and that is why OPPP figures
into each teamlevel stat.
FG = Pts  OPPP
FGM = OppReb% x OPPP
REB = OppReb% x OPPP
TO = OPPP
STL = OPPP
You do not need to know your own pts per poss to figure out the
effect each stat has on your net points or "value added". By this
method of accounting, it doesn't matter if it is easier to score
following an offensive rebound because it is only when you actually
score that the value is added.
With free throws, the values are:
reboundable FT = 1  OPPP
reboundable FTM = OppReb% x OPPP
nonreboundable FT = 1
nonreboundable FTM = 0
Jim Tang
 In APBR_analysis@yahoogroups.com, "Kevin Pelton"
<kpelton08@h...> wrote:>
per
> I wouldn't say _exactly_ right. There's no reason opponent points
> possession should enter the equation, because the opponents are
*ORTG
> getting the same number of possessions regardless of whether the
> offense makes the shot or misses it.
>
> What's being affected is the team's own "minor possessions"
> or "plays"  it's getting extra shots at the basket because it's
> rebounding more of its own shots.
>
> So the relevant equeation would be PTS  FGA + (FGAFGM)*OREB%
> (based on plays).
given
>
> The added value of missed shots, above and beyond turnovers, is
> by the team's offensive rebound percentage times its points per
as
> possession.
>
> Of course, this assumes that an offensive rebound "play" is just
> valuable as a normal "play". In fact, most research seems to
indicate
> that it's more valuable. (Right?)
>
> There also needs to be an adjustment made for missed free throws,
> half of which, similarly, have a chance of being rebounded by the
> offensive team. 0 Attachment
 In APBR_analysis@yahoogroups.com, "ptbnl123" <ptbnl123@y...>
wrote:
>
Correction, this should say "It's true that your opponent has a
> It's true that your opponent gets the ball back regardless of
> whether your shot is made or missed, and that is why OPPP figures
> into each teamlevel stat.
chance to get the ball back regardless..."
To address "why OPPP figures into each team level stat" despite the
fact that "the opponents are getting the same number of possessions
regardless of whether the offense makes the shot or misses it", I
think it's an issue of quality vs quantity. The quantity of opponent
possessions may be the same but the quality of them (OPPP) is what
affects the value of the stats.
JT 0 Attachment
You can go in circles thinking about this stuff.
Giving up possession is an inevitability, so I don't see how you can
minus it for a missed field goal but not a made one. In fact, I don't
see how you can minus it at all, since you'll give up possession even
if you DON'T shoot.
Maybe you can average what a player does with a possession in
comparison to points per MINOR possession.
So the formula I guess would be points scored (whether the field goal
was missed or made) minus points per minus possessions. An offensive
rebound generates another minor possession. A turnover ends a major
possession.
Just an idea. I don't even know where to start with free throws,
blocks and assists.
MonĂ© 0 Attachment
 In APBR_analysis@yahoogroups.com, "John Hollinger"
<alleyoop2@y...> wrote:> But in reality those two aren't equivalent. I'd rather go 2 for 6
on
> 3s, because I have an extra chance at an offensive rebound.
In a pickup game, you might do well by this strategy. But in the
NBA, 6 2pt attempts are typically accompanied by 2+ FTA  from
which, almost 2 more points will result.
But we've gone into rather unreal hypothetical situations anyway.
If you rebound your missed 3 right under the basket, do you pass it
back out for your next 3, rather than following it in?
The 3point shot and the drive to the basket will always be co
dependent, in their effectiveness. The threat of one boosts the
effectiveness of the other  even when one may appear to be more
effective. 0 Attachment
 In APBR_analysis@yahoogroups.com, "Dean Oliver" <deano@r...>
wrote:> > .. I add and subtract "rates", which
assists, rebs, etc.?
> > are tweaked by team scoring/rebounding rates.
>
> Per minute rates? Rates of? ...> Do you do something similar for
Rebound "rate" is a proportion of the team rebounds allowed, i.e.,
opponent rebounds. This differs from % of total available rebounds
(which is how I used to do it), but it seems to agree better with
cases of players moving from better to worserrebounding teams (and
vise versa).
The theory is that on good rebounding teams, you will be competing
against your own teammates more than if you are the only good
rebounder out there for your squad. I haven't checked the viability
of this idea, but it does seem to give better team ratings.>
players
> >
> > I still don't get team rates that summarize team success. Good
> > defensive teams are still undervalued in my system. Maybe team
> > defense isn't a function of individual ability.
>
> despite the fact that team defense is a function of choices, what
> we are all measuring is performance  what players do. The
> implement what a coach says. If a measurement is still missing
good
> defensive teams, it's missing part of performance and missing part
of
> what we'd like to predict.
I do agree. But do players really "improve" when they join a better
coached team? Does "chemistry" change how good a player is for the
moment, but make for bad predictions if their environment changes?
If I can get a good estimate of a players "rebounding ability", that
is pretty much transferable to another context. Scoring, likewise.
Defense is more contextdependent.
So "performance" might be defined as "contributing to wins"; or it
might be defined as "being productive".
I guess I think some coaches get more out of the same talent; and
some playercombinations just "work better" than others. These are
interrelated, and don't necessarily define the "worth" of a player.
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