With the NBA Draft tonight, I often wonder how close the college game is to the professional one. Itâ€™s clear who the stars in the college game are. But are they just â€œbuiltâ€ for that style of play, or are they true stars who excel at any level (including the NBA)?
I have attempted to solve this problem by seeing how college stats correlate to NBA stats. To do this, I first took a large sample size of current NBA playersâ€™ career statistics and compared it with those sample playersâ€™ college stats. Everything was calculated on a per-minute basis. Once I had the stats, I ran a series of simple regressions to see how well the NBA numbers correlated with the college ones.
Below I have posted the R^2 values of the different correlations. R^2 basically says how well future outcomes are likely to be predicted by the model and can be thought of as a percentage. For example, if the R^2 of the correlation between college points per game and NBA points per game is 0.3405, then we can say that about 34.05% of NBA playersâ€™ PPG can be explained by their college PPG. The higher the R^2, the better.
Below are the R^2â€™s for the different correlations:
Points per minute: 0.3405
Field goal attempts per minute: 0.3522
Field goal percentage: 0.3436
Three-point attempts per minute: 0.6391
Three-point percentage: 0.7941
Free throw attempts per minute: 0.286
Free throw percentage: 0.7615
Rebounds per minute: 0.8312
Assists per minute: 0.8823
Steals per minute: 0.5981
Blocks per minute: 0.9327
Turnovers per minute: 0.4535
Personal fouls per minute: 0.4447
Those numbers are all higher than I expected before I began the study. Specifically, we can predict with pretty good certainty an NBA playerâ€™s blocks, assists, rebounds, three-point percentage, and free throw percentage based on their equivalent college statistics. Free throw attempts, points per game, field goal percentage, and field goal attempts are the weakest.
This all comes with one big caveat. The sample only includes guys that have made it in the NBA. The college stars that fizzled out at the pro level or the guys who NBA teams knew had no chance at the highest level before the draft were not included in this study. In other words, just because a guy is great in college doesnâ€™t mean he will be great in the NBA. However, if he does make the NBA, we can somewhat predict how heâ€™ll end up doing based on his college stats.