NBA Adjusted Efficiency Rankings 1-5-2011

There are many ways to rank NBA teams; some better than others. This method runs as follows:

1. Compile all game advanced team boxscores from Basketball Reference, like this one:
   

   		Four Factors
   	Pace	eFG%	TOV%	ORB%	FT/FGA	ORtg
   SAS	90.8	.506	13.8	32.6	.186	113.4
   BOS	90.8	.647	15.5	18.5	.107	115.6

2. Adjust efficiency differential in the game for location and rest days.
3. Solve for each team’s efficiency differential by minimizing the residuals^1.5 for each game (using Excel Solver)
4. Generate an offense-defense skew for each team by solving for average efficiency in games that team plays, adjusted for rest days (minimizing residuals^1.5 again).
5. Use the offense-defense skew and the team’s efficiency differential to generate offensive and defensive ratings for each team.
6. Apply the same methods to generate pace values for each team

So this method differs in a few ways from some others:

1. It weights each GAME equally, rather than each possession (I don’t want a fast-paced OT game to mean more in the ratings than a slow game).
2. I minimize residuals^1.5 rather than squared residuals.  I suppose a true average would use squared residuals, but I liked the fact that using ^1.5 causes outliers to have less of an effect.  Research is needed to figure out what is the proper approach–for retrospective ratings, ^2 is probably best, but for predictive perhaps something less than ^2.  This was simply a judgment call on my part.

So anyway, here are the ratings.  I’ll show them both in lovely Excel-conditional-formatting splendor (which would be a headache to code as CSS–only Ken Pomeroy has done it that I know of!) and then I’ll post them in table format as well for easy sorting and copying.

Adjusted NBA Team Efficiencies, through 1-5-2011

And for sorting and copying, here is the nice table form: