Those who know me, know I'm a stat geek, so advanced statistics always interest me. I saw this linked over at blogabull.com.
Stephen Ilardi of basketballvalue.com recently posted on the APBRmetrics board with updated 6 year adjusted plus minus numbers (70%
weighted towards this past season and weighted greater for the most
recent years of the remaining 30%). I decided to look through the
current Bulls remaining on the team to get a sense of what we might be able to expect from this team next year.
Player, 2008-09 Minutes, Off. APM, Def. APM, Std. Error, Total APM
1. Brad Miller, 2100, 1.96, 3.00, .98, 4.96
2. Joakim Noah, 1911, .89, 2.87, 1.1, 3.76
3. Kirk Hinrich, 1338, 1.12, 2.38, .96, 3.50
4. Luol Deng, 1627, -.48, 2.35, 1.03, 1.87
5. Ben Gordon, 2974, 3.02, -1.53, .99, +1.49(d'oh!)
5. Aaron Gray, 693, -1.74, 2.7, 1.56, .96
6. Derrick Rose, 2977, 2.03, -1.70, 1.13, .33
7. Tyrus Thomas, 2175, -5.05, -.53, 1.02, -5.58
8. John Salmons, 2959, -1.8, -5.35, .91, -7.14
On the roster but missing in the numbers along with reasons they didn't make it: Jannero Pargo (Europe), James Johnson (rookie), Taj Gibson (rookie), Lindsey Hunter (not enough minutes), Jerome James (corpse).
The longer I've seen use of the +/- stat the less validity I think it has. First, you have to be dealing with the adjusted +/- and not the standard yahoo/nba/boxscore +/-. Adjusted +/- can be found on 82games.com, and it adjusts the +/- to a per minute basis relative to how the team performs with and without you on the court.
The point being that a bad team would give all players hugely negative scores and a good team would give all good players very positive scores regardless of the players impact. The Cavs won the vast majority of their minutes on the floor, does that mean all of their players deserve a huge +/-? Looking at the difference between when they are on and off the floor improves the statistic 10 fold. These numbers do use adjusted +/-, so this is more of a note for those playing at home and doing their own studies.
It still falls short of being all that useful though, because you have things like the LeBron factor. Using the Cavs as an example, if a player plays basically all of his minutes with LeBron and another guy plays half with and half without then guess who's +/- is better? Caliber of competition makes a difference too. A deep team's second unit may fair much better in the stat than it's first unit because teh players are similar in caliber but consistently get more minutes against weaker competition.
Anyway, disclaimer's aside, what would these numbers tell us if we believed them. The most eyepopping number might be that John Salmons was pretty scary bad in +/-. However, it's worth noting that his +/- as a Bull was a + .9 rather than a negative. Our first clue these numbers may not mean much and mitigate the damage.
Next, you'd notice that Derrick Rose would have been 7th on the team last year, not what you'd expect given the media hype. This one doesn't surprise me as I've often felt that over 36 minutes Kirk Hinrich was giving the Bulls as much quality as Derrick Rose was, especially if you factor Ben Gordon being on the court which removes some of the value of Roes's shot creation ability (since Gordon can be a primary shot creator). Hinrich also had an excellent year while healthy and after being overrated two seasons ago appears to be underrated to me again. The value of Rose's replacement probably hurt his numbers in this example.
Our big men, at least two of them, played pretty darn well. Noah and Miller were our two best players in the statistic which is interesting given that we feel the team's biggest problems are in the frontcourt. I think Noah benefited from playing on the bench for much of the year and not playing big minutes early in the season, especially as a starter, when things were going bad. Plus he was a huge +/- player his rookie year.
Unfortunately, I don't think this is a correlation proves casuality thing going on here. The high marks for these two don't mean that they're our most important players or close to it. Tyrus Thomas always did fairly well in +/- in the past, but his numbers fell off a cliff this season. Again, this is likely related to the Bulls traditionally having a very deep team and their bench players getting better numbers than their starters as described above.
What is there to ultimately take from this? Probably not a whole lot. There are too many facters influencing +/-, and any stat that doesn't directly measure what a player does has to be a bit fishy to begin with.