Statistical +/- is a metric originally created by Dr. Dan Rosenbaum in 2004 that is intended to predict a player's adjusted +/- ratings based on box score data. He used a regression of box score stats vs. adjusted +/- to determine the coefficients of different variables in the formula. Neil Paine at Basketball-Reference.com has tweaked and updated the statistical +/- formulas by including data for the last couple years, as well as adding new variables for a player's height and age. Statistical +/- is not perfect, and I am not completely convinced that Rosenbaum & Paine selected the correct variables to use in the regression (the "versatility index" especially seems like it could be improved upon), but it is still an intriguing approach to the problem of creating a way to evaluate players and I believe that it is superior to the more commonly used metrics like PER and Win Score. Although it is called statistical +/-, this metric is box score based and does not actually use any +/- data (although there is a team adjustment to make sure that a weighted sum of a team's players' statistical +/- will equal the team's +/-).
How do the Blazers do in Paine's new statistical +/- ratings?
Roy is 9th in the NBA (behind LeBron, CP3, Wade, Ginobili, Howard, Kobe, Duncan, and Kidd). He is a stud, and pretty much all metrics agree on that at this point.
Rudy did better than I would have expected, since although adjusted +/- loves him most box score based metrics don't. Statistical +/- likes 3-point shooters. Rudy is the #1 rookie in the NBA (if you don't count people like Hamed Haddadi who have barely played any minutes).
Oden has had a pretty good rookie season when he has been able to stay on the court.
Blake has had a good season, his statistical +/- rating is close to being the same as his adjusted +/- rating.
Aldridge is lower that I would have expected, but is still considered an above average player.
Batum does pretty well in statistical +/-, which is a bit surprising. He also does very well in adjusted +/-, but most people looking at his box score stats would not think he is that good and the formula shouldn't have any way of figuring out that he is a lock-down defender.
Przybilla helps the team a little more on defense than he hurts them on offense.
Sergio is rated as a slightly below average player, but that is still much better than how he is rated by adjusted +/-.
Outlaw normally does fairly well in box score-based metrics, but statistical +/- doesn't like him very much. Adjusted +/- doesn't like him much either.
Frye and Bayless have obviously both had terrible years this season.
I was actually a bit surprised by how closely the statistical +/- ratings matched the adjusted +/- ratings for a lot of players. Considering that the two metrics use completely different types of data to rate players, it would not be surprising to see a bunch of major disagreements between the two metrics. The fact that the correlation is as strong as it is suggests that statistical +/- is doing a good job of what it is intended to do.