## Re: The Problem with Possessions-Based Linear Weights

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• I think wimpds has a point here. If a particular player with limited offensive skills tends to play at times when his teammates shoot more poorly (because they
Message 1 of 42 , Mar 30, 2004
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I think wimpds has a point here.

If a particular player with limited offensive skills tends to play
at times when his teammates shoot more poorly (because they are in
essence playing 4 on 5) than their WINVAL ratings suggest they
should, that player would end up with more offensive rebounding
opportunities than a typical player.

But let's suppose a guy is on the floor for 80 possessions in 40
minutes and he drops his team's shooting percentage down 5
percentage points (a pretty big drop). I would assume that would
result in about three to five extra offensive rebounding
opportunities for this player and if he collects 10 percent of those
extra rebounds, this amounts to 0.3 to 0.5 extra offensive rebounds
per 40 minutes. Not trivial, but also not a huge difference.

--- In APBR_analysis@yahoogroups.com, "wimpds" <wimpds@y...> wrote:
> But if teammates are more likely to miss shots when they play with
you
> than when they play with other players, that will depress your
WinVal
> rating, right? If this attribute is correlated with individual
> offensive rebounding, won't it have a negative effect on the value
of
> the coefficent?
>
> On the defensive side, we only have a few variables to contribute
> significantly to your WinVal rating. [I'd be interested in seeing
> regressions run separately on the offensive and defensive WinVal
> ratings.] Defensive Rebounds coefficient might be picking up
> something more than simply rebounding ability, it could be getting
at
> defense somewhat more generally.
>
>
>
> --- In APBR_analysis@yahoogroups.com, "Michael Tamada"
> wrote:
> > It's a good thought, although the regression should already
> > account for this by already measuring the impact of
> > opponents missing shots and one's team missing shots.
> >
> >
> > --MKT
> >
> >
> > -----Original Message-----
> > From: wimpds [mailto:wimpds@y...]
> > Sent: Monday, March 29, 2004 3:13 PM
> > To: APBR_analysis@yahoogroups.com
> > Subject: [APBR_analysis] Re: The Problem with Possessions-Based
Linear
> > Weights
> >
> >
> > Another thought on this subject ( though I may not be thinking
through
> > the regression carefully enough) is that offensive rebounds are
> > probably correlated with having teammates missing shots while
> > defensive rebounds are correlated with the opponent missing
shots.
> > This effect would seem to be even stronger if your teammates are
more
> > likely to miss because you're not attracting any defensive
attention.
> >
> >
> >
> >
> >
> > --- In APBR_analysis@yahoogroups.com, "carlos12155"
> > <carlosmanuel@b...> wrote:
> > > --- In APBR_analysis@yahoogroups.com, "Mike G" <msg_53@h...>
wrote:
> > > > --- In APBR_analysis@yahoogroups.com, "Kevin Pelton"
> > > > <kpelton08@h...> wrote:
> > > > >
> > > > > Rodman specialized in rebounding -- not offensive
rebounding. He
> > > > was
> > > > > great at both ends. I don't know if I can think of someone
who
> > > > > specializes specifically in offensive rebounding.
> > > >
> > > > The original poster meant, I'm sure, that on Offense, Rodman
did
> > > > little more than rebound missed shots, at least by the time
in his
> > > > career when he was with the Bulls.
> > > >
> > > > Obviously, he went to the other end of the court on defense,
and
> did
> > > > other things there.
> > > >
> > >
> > > That was exactly my intention. It seemed to me that if
offensive
> > > rebounds are at some level a negative, Rodman performance
would be the
> > > perfect example; after all that was the only thing he did on
offense.
> >
> >
> >
> >
• I think wimpds has a point here. If a particular player with limited offensive skills tends to play at times when his teammates shoot more poorly (because they
Message 42 of 42 , Mar 30, 2004
• 0 Attachment
I think wimpds has a point here.

If a particular player with limited offensive skills tends to play
at times when his teammates shoot more poorly (because they are in
essence playing 4 on 5) than their WINVAL ratings suggest they
should, that player would end up with more offensive rebounding
opportunities than a typical player.

But let's suppose a guy is on the floor for 80 possessions in 40
minutes and he drops his team's shooting percentage down 5
percentage points (a pretty big drop). I would assume that would
result in about three to five extra offensive rebounding
opportunities for this player and if he collects 10 percent of those
extra rebounds, this amounts to 0.3 to 0.5 extra offensive rebounds
per 40 minutes. Not trivial, but also not a huge difference.

--- In APBR_analysis@yahoogroups.com, "wimpds" <wimpds@y...> wrote:
> But if teammates are more likely to miss shots when they play with
you
> than when they play with other players, that will depress your
WinVal
> rating, right? If this attribute is correlated with individual
> offensive rebounding, won't it have a negative effect on the value
of
> the coefficent?
>
> On the defensive side, we only have a few variables to contribute
> significantly to your WinVal rating. [I'd be interested in seeing
> regressions run separately on the offensive and defensive WinVal
> ratings.] Defensive Rebounds coefficient might be picking up
> something more than simply rebounding ability, it could be getting
at
> defense somewhat more generally.
>
>
>
> --- In APBR_analysis@yahoogroups.com, "Michael Tamada"
> wrote:
> > It's a good thought, although the regression should already
> > account for this by already measuring the impact of
> > opponents missing shots and one's team missing shots.
> >
> >
> > --MKT
> >
> >
> > -----Original Message-----
> > From: wimpds [mailto:wimpds@y...]
> > Sent: Monday, March 29, 2004 3:13 PM
> > To: APBR_analysis@yahoogroups.com
> > Subject: [APBR_analysis] Re: The Problem with Possessions-Based
Linear
> > Weights
> >
> >
> > Another thought on this subject ( though I may not be thinking
through
> > the regression carefully enough) is that offensive rebounds are
> > probably correlated with having teammates missing shots while
> > defensive rebounds are correlated with the opponent missing
shots.
> > This effect would seem to be even stronger if your teammates are
more
> > likely to miss because you're not attracting any defensive
attention.
> >
> >
> >
> >
> >
> > --- In APBR_analysis@yahoogroups.com, "carlos12155"
> > <carlosmanuel@b...> wrote:
> > > --- In APBR_analysis@yahoogroups.com, "Mike G" <msg_53@h...>
wrote:
> > > > --- In APBR_analysis@yahoogroups.com, "Kevin Pelton"
> > > > <kpelton08@h...> wrote:
> > > > >
> > > > > Rodman specialized in rebounding -- not offensive
rebounding. He
> > > > was
> > > > > great at both ends. I don't know if I can think of someone
who
> > > > > specializes specifically in offensive rebounding.
> > > >
> > > > The original poster meant, I'm sure, that on Offense, Rodman
did
> > > > little more than rebound missed shots, at least by the time
in his
> > > > career when he was with the Bulls.
> > > >
> > > > Obviously, he went to the other end of the court on defense,
and
> did
> > > > other things there.
> > > >
> > >
> > > That was exactly my intention. It seemed to me that if
offensive
> > > rebounds are at some level a negative, Rodman performance
would be the
> > > perfect example; after all that was the only thing he did on
offense.
> >
> >
> >
> >