BPM_Team_Adjustment is a bit challenging to accept and not misunderstand for me. So I had a few questions. They too are perhaps a bit challenging to understand but I want to try.
The BPM_Team_Adjustment makes the results of this metric a ranking
rather than a precise individual impact estimate because of the 120% inflation, if I am following?
Would there be an acceptable way to adjust this adjustment so that it reflected the actual or actual - adjusted team performance data of individual players when on the court vs their teammates when on court, instead of giving the same adjustment to all based on all minutes, including when not on the court?
Would there be an acceptable and separate way to account for just the performance change seen for when teams are leading or trailing (by some unspecified amount) so that it reflect the actual performance impact for that player instead of being team or league average change? The play by play data exists for recent years and I assume JE essentially has a player specific adjustment because it is based on number of actual player minutes meeting his critieria (correct?)
Even if one didn't redo the team adjustment, is there an understanding of how much of it is related to the blowout performance time issue versus other things about the team?
If one looked at BPM without the team adjustment and without blocks, would that be essentially equivalent in terms of what is covered / included to RPM (or RAPM) - defensive adjusted points per shot (more precise if it were for one year)? What is the R2 for defensive BPM and RPM (or RAPM) - defensive adjusted points per shot? Is it more impressive and, if so, shouldn't that be trumpeted to counter those who complain the r2 is too low to give it much weight?
I intend to compare defensive BPM to defensive RPM (or RAPM) - defensive adjusted points per shot. I wonder how close they are. If they are close on average I might start looking at defensive BPM + defensive adjusted points per shot. Is it correct to think that the "error" in RPM is present in the every component of BPM including the team adjustment? Is there any basis to suspect there is more error in the team adjustment quantity? Is there any basis to suggest that rather than remove col-linearity issues that they have just been shifted into the team adjustment? I am just asking, not actively presuming.
If someone (not necessarily you Daniel, given your stated positions) wanted to separately try to model the missing defensive component not in current BPM (I'll call it broadly shot defense), what to try? Minutes again, team opponent pts per shot, counterpart pts per shot, height, years of experience, what else? Could some of these terms be significant for this portion of the project when they weren't for the original BPM effort? What significance does sqrt(AST%*TRB%) have for this portion of the project? Is there any basis for assuming that BPM or BPM enhanced with shot defense (via use of defensive adjusted points per shot or regression based model or combination) has less "error" than RPM / RAPM?
Anyone interested in running a DBPM that is an exact mirror of OBPM?
Overall for BPM what is most different at the stat coefficient level when compare to the last version of ASPM or the last public version's of Neil Paine's SPM? (to OR/DR winshares too)? For comparison with Neil's http://www.basketball-reference.com/blog/?page_id=4122
(is this the most recent public version?) He has TSA/36 separate from assists, whereas you have usage. PFs included in the model here.
(Age and height are 2 differences in a previous version http://www.basketball-reference.com/blog/?p=2191
Versatility Index was the cube root of Pts/40*Ast/40*Reb/40, where you you a ast/reb interaction term)
If one laid out BPM, shot defense enhance BPM, XRAPM, would there be any appropriate use for machine learning to find optimal blend of these metrics for retrodiction or prediction or both? Or to find a new metric that is essentially based on this optimal blend?
Is there anything in this article http://www.basketball-reference.com/blog/?p=8339
that contributes to the discussion?
In the regression what exactly is Shot%? It didn't make it into final BPM in any fashion? Not significant or...?
Is there anything from old or new IPV that is different, discussable and potentially helpful for BPM or anything beyond it?
Is there different meaning / reason to compare BPM to play by play, game level or level level actual scoreboard instead of to RPM? (Isn't this one of Berri's main / old complaints? Is there any reason to address that further here and now?)
I know this jumps around and is probably behind the knowledge curve in some areas. Any clarifications or additional thinking about the topics will be appreciated.