from Amazon
Sunday, July 27, 2008
Minor to major correlations
I ran year-to-year correlations for various stats for players who played in AA or AAA in one year and in the majors the next year. They had to have at least 300 PA in both years. I regressed minors (AA or AAA only) 00 on majors 01, minors 01 on majors 02, etc., from 00 to 07. The minor league stats are MLE’s and are park neutral. The major league stats are park (and opponent) neutral also. Here are the results:
Keep in mind that my MLE coefficients are based on players from pre-2000 (that played in the minors and majors in the same year and in consecutive years), so that I am not “cheating” in calculating these correlations, although since they are linear coefficients, I am not sure that would matter. Anyway....
The average number of minor league PA was 450, and the next year, the average number of major league PA was 464.
There were 195 data pairs (player seasons) in the regression.
BA .285
OBA .384
SA .388
OPS .331
Sngl per PA .604
Dbl per PA .219
Trp per PA .445
HR per PA .665
BB per PA .699
SO per PA .756
Those are some decent correlations ("r").
Here are the corresponding numbers for players who played in the majors in one year and the majors in the next year, again with a min of 200 PA per year (average of 503/496):
N=1875
BA .391
OBA .565
SA .607
OPS .593
Sngl per PA .580
Dbl per PA .230
Trp per PA .417
HR per PA .721
BB per PA .744
SO per PA .837