So why do we see more expensive teams getting more bang for their buck starting around 2007 or 2008?
My hypothesis is that we see a shift in 07/08 because that’s when team’s really started looking at basketball statistics and making front-office decisions with a focus on more than just field goal percentage and assist-to-turnover ratio.
For example, Dean Oliver, considered one of the founding fathers of basketball statistics, was hired as a full-time NBA analyst in 2004 and has served in front office roles with the Seattle SuperSonics (R.I.P) and the Denver Nuggets.
Because of the increased role and proliferation of basketball statistics in the NBA (even if it is on a marginal level) I think that teams have become more aware of very efficient players, and very inefficient players. And thus, teams have been able to spend money on the efficient players, and been able to stay away from the inefficient players.
The other thing to notice is that teams are better at getting bang for their buck on the offensive end, but not on the defensive end. Maybe this is because key offensive attributes (shooting form, passing ability, etc.) are easier to see and identify than key defensive attributes (anticipation, good hands, understanding of help defense). Or maybe when you pay players, they focus more on scoring points than playing defense.
Finally, while salary and how well a team plays have become more correlated recently, there’s still a lot more improvement for teams to make, and become more efficient.