Basically what I did was take the top 75 offensive college players who were drafted and played rookie ball in 2009. I weighted their stats by the lowest PA total (in college or in RK) for all players. Once the PA were equal I compared all the college numbers to the RK league numbers and created factors, which we will call Rookie League Equivalencies (RKLE).
The factors can be applied to a player's adjusted college stats to give a rough projection of how he will perform in Rookie-ball.
The factors are as follows:
The key stats I put in bold. As I had hypothesized walks carry over pretty highly. Strikeouts are likely to increase, so a player who strikes out a lot in college will strike out even more in the low levels of the minors.
Obviously one season of players is not a huge sample size and I will ideally add to this database. I also plan to expand to Low-A and other levels if there are large enough samples