Over the last couple of days I've gotten to work on using Neil Paine's version of Statistical +/- to look at the Bulls so far this year. I shared some of my results in the post on Hollinger's critique of Rose vis-a-vis Brook Lopez when the discussion got somewhat sidetracked. I decided I would take it as an opportunity to make a FanPost about the results and share them all in one place so as not to distract too much from the focus of that discussion (whether or not Derrick deserves the Rookie of the Year).
Using the metric is relatively straightforward. I pulled the Bulls season totals data from basketball-reference.com and put it into an excel spreadsheet. Then, I used the b-r.com data on pace to adjust the numbers and figure out each players' pace adjusted per 40 minute stats. I calculated the relevant statistics for calculating statistical +/- as outlined here by Dan Rosenbaum. The relevant stats are:
PTS - points per 40 minutes
TSA - true shooting attempts per 40 minutes
FTA - free throw attempts per 40 minutes
TA - three point attempts per 40 minutes
AS - assists per 40 minutes
OR - offensive rebounds per 40 minutes
DR - defensive rebounds per 40 minutes
ST - steals per 40 minutes
BK - blocks per 40 minutes
PF - personal fouls per 40 minutes
MPG - minutes per game
True shooting attempts just = FGA+.44*FTA. Then I used the coefficients provided for by Dan Rosenbaum in the previously mentioned link to calculate raw statistical plus minus for offense and defense. After that, I used Neil Paine's method of forcing the Bulls offensive efficiency differential relative to rest of the league and defensive efficiency differential relative to the rest of the league to fit with the numbers. He explains it here to me. So I did this for the Bulls through 69 games this season and posted those results and Scotter and YaoPau mentioned they'd like to see more seasons. Thus far, I've been able to do the 06-07 and 07-08 seasons in addition to the current season.
Note: OSPM = Offensive Stat. Plus Minus, DSPM = Defensive Stat. Plus Minus, and TSPM = Total Stat Plus Minus
2006-07 Chicago Bulls by Statistical +/-
2007-08 Chicago Bulls by Statistical +/-
2008-09 Chicago Bulls by Statistical +/- (through 69 games)
Some quick thoughts:
One thing that jumps out about last season is just how few positive Stat. +/- guys we had and how low the magnitudes were on those positive contributors - Ben Wallace leading the way at 1.21? yikes. Especially when we compare that with 06-07 where there 7 players contributing positively with Ben Wallace again leading the way but this time at a much higher magnitude of +4.26.
Another couple of trends that immediately leap out to me. Luol hasn't had a positive season by Statistical +/- this year or last year, but was a positive in 2006-07. This seems to fit with my subjective notions of last year and this year where Luol hasn't looked nearly as sharp, but doesn't fit with the pure adjusted +/- numbers that Luol put up last year and this year, via 82games.com (07-08: +4.95) and basketballvalue (08-09: +2.11), respectively. What might explain some of the discrepancy is that 82games's Ilardi numbers use data from five years to reduce the noise level, so Deng was still getting credit for his 06-07 season and the seasons prior where he was very good. As far as basketballvalue goes, their estimates are still noisy and as they've gotten less noisy over the course of the year, due to more observations / larger sample size, Luol's adjusted +/- has continued to free-fall from around a +4 to now around a +2 with a 2.8 standard error, so it's certainly within the 95% confidence interval that Deng could be a negative contributor.
Kirk Hinrich ends up looking quite good, which strikes me as strange because it's a boxscore based metric and Kirk never puts up stats that wow anybody. However, it appears that he may be doing things that contribute more than they get credit for traditionally.
Tyrus also ends up looking pretty good and you can really see how great his defense is using this metric. And Jo Noah looks like the beast that I've always believed him to be (bad on O because he doesn't space the floor or score a lot, but great on D).
One last point is that Derrick looks like one of our worst players, but that's actually to be expected. Point guards typically don't do very well by statistical +/- or pure adjusted plus-minus, especially with regards to defense. Further, rookies, as you'd expect, tend to be pretty bad by Stat +/-. In his opening post on using Stat +/- as a predictive tool, Neil Paine wrote:
I also went back and found that the minute-weighted average SPM for all rookies in the lottery era was -2.16, so I assigned that value for every rookie (clearly this understates the value of your O.J. Mayos and Derrick Roses, but I wanted to keep things relatively simple).
So we can see (and Neil even acknowledges Derrick by name), that Derrick's -1.69 Stat. +/- isn't THAT worrisome, because it's better than the average for rookies in the lottery era and because Derrick is playing a position that typically looks pretty poor by this metric. We might even say Derrick is ahead of the curve. Which is certainly a good thing.
Anyway, I'm sure there's plenty more insight to be added by looking at these numbers, but I'll leave that to you all. Those were my initial thoughts based on a quick gloss over the numbers.