Association for Professional Basketball Research Metrics
This association has been working so many years ago on the quantification of all aspects of the game building standard statistics baselines and making some new concepts related to basketball very popular.
I can spend hours looking into the numbers of this site. I would like to see what else is behind the scene, they just offer limited stats.
In any case is a nice reference of data.
Modeling Basketball’s Points per Possession With Application to Predicting the Outcome of College Basketball Games
This essay contains some basic information about different basic ways to calculate the performance of a player or team per posession. I like the analysis Ryan does about the different models he used, it results very didactic.
Do you know any other place where to dig into this type of basketball statistics?