## Re: [APBR_analysis] Times Fouled and Possessions

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• I have noticed that many people have used the following formula to estimate possessions: FGA + (FTA)(.4) + TO - OReb The times fouled shooting factor should be
Message 1 of 8 , Jun 22, 2003
I have noticed that many people have used the following formula to
estimate possessions:

FGA + (FTA)(.4) + TO - OReb

The times fouled shooting factor should be .457; not .4.

Or you can get more complex with your possession formula, something BobC has done.

the proper formula is:

FGA + FTA/2 + TO - oreb - techFTA - (AOSF FGM) - flagrants

(denominator 2 larger prior to 81-82 when 3 to make 2 bonus was in affect), but i add 0.33 to account for the techs and flagrants...

and not more complex, just more exact, simply because it works in a simulation, which does not take into account technicals and flagrants, but does account for AOSF FGM (act of shooting fouls FGM, i.e. traditional 3 pt plays)...

your average for 97-98 (the last year i updated the sim) was 92.4 poss/48 min/team. the sim uses 91.5 on average and the stats come out pretty much exact (i.e. avg pts/g/team right on the money, well within 1%)....

if you ever run the B-BALL sim for a full season (takes about 40 seconds on a pentium to run an 1189 game season) it lists each team's poss/g in the final stats file...

bob chaikin
bchaikin@...
• I agree with the general sentiment -- if 0.4 vs. 0.44 would only change the result between two players are teams with microscopic differences. Also, in the
Message 2 of 8 , Jun 22, 2003
I agree with the general sentiment -- if 0.4 vs. 0.44 would only
change the result between two players are teams with microscopic
differences.

Also, in the specific example that brought up this thread, there's a
couple things missing -- times fouled on 3-pointers, flagrant fouls
and breakaway fouls -- that would further adjust the coefficient.

--- In APBR_analysis@yahoogroups.com, "Dean Oliver" <deano@r...>
wrote:
> --- In APBR_analysis@yahoogroups.com, igor eduardo küpfer
> <igorkupfer@r...> wrote:
> > <snip>
> >
> > The following is a comparison of the two FTA coefficients (.4
> vs .457), as
> > shown by the differences between offensive possessions and
defensive
> > possessions,by season. The smaller coefficient outperforms the
> larger
> > exactly half the time, although with a larger standard error. The
> difference
> > is small enough (to me) as to not warrant using the extra decimal
> places.
> > What is needed is some empirical data, counting actual
possessions
> in a
> > game, and seeing how close we are.
>
> I've got some of these. I'll try to pass them on after I'm done
> traveling (again).
>
> My general comment to Ben when he first passed on his note to me
was
> that he may be right that 0.45 works better to account for FT
> possessions. However, there are minor errors in the rest of the
> possession formula associated with team ORs and other little things
> that get lumped into that multiplier on FTA. Or you can get more
> complex with your possession formula, something BobC has done.
>
> I share the sentiment that it doesn't matter too much. Soon, we
will
> be able to just count possessions for each team and do the simple
> division to get pts/poss. Still, the formula estimate will remain
> useful (in historical work, in individual possession calcs), but
the
> difference between 0.4 and 0.45 won't make a huge difference in
> estimates. Plus, the multiplier changes with rules and enforcement
> of such. It was lower in the 3-to-make-2 era, for example, and is
> higher in the 1-and-1 world of college hoops.
>
> DeanO
• ... affect), ... The problem is that your last 3 terms aren t available in most stat books so we end up estimating them. I just end up rolling them into the
Message 3 of 8 , Jun 23, 2003
--- In APBR_analysis@yahoogroups.com, bchaikin@a... wrote:
> the proper formula is:
>
> FGA + FTA/2 + TO - oreb - techFTA - (AOSF FGM) - flagrants
>
> (denominator 2 larger prior to 81-82 when 3 to make 2 bonus was in
affect),
> but i add 0.33 to account for the techs and flagrants...
>

The problem is that your last 3 terms aren't available in most stat
books so we end up estimating them. I just end up rolling them into
the multiplier on FTA, but there are other ways.

DeanO
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