Comparing Offensive Environments in the Minor Leagues

Part of prospect ranking time for me, is not just reviewing and analyzing the players, but instead also taking the opportunity to test my own assumptions. One of the things I want to be especially careful about this year, is adjusting a player's performance by the league's offensive levels in addition to a player's own age. Also, I hadn't seen a chart on the Internet for the average offense of level for each minor league. So, here it is for each league in which the Mets have an affiliate.

	AVG	OBP	SLG	BABIP	BB%	SO%	XBH%	HR%
NL - MLB	.259	.331	.409	.299	8.97	18.37	7.68	2.49
IL - AAA	.262	.328	.395	.304	8.19	17.79	7.37	2.00
EL - AA	.258	.332	.385	.304	9.08	18.18	7.09	1.77
FSL - A+	.252	.322	.363	.303	8.24	19.01	6.31	1.41
SAL - A	.254	.324	.368	.314	7.91	20.67	6.60	1.42
NYP - SSA	.245	.320	.351	.304	8.66	20.42	6.22	1.10
APP - R	.257	.328	.384	.316	8.13	21.01	7.05	1.73
GCL -R	.238	.316	.335	.297	8.63	20.45	5.93	0.92

I had seen it written and accepted as a baseball truism that batting average on balls in play (BABIP) declines up the ladder towards the big leagues, because 1. The players are better defensively and 2. Fields are better. So, does BABIP drop as players move up the ladder? Not much. It is true, that the MLB BABIP is lower than any minor league level except the GCL.  On the other hand, the batting average on balls in play is essentially identical for three of the four full season leagues where the Mets have an affiliate, the AAA International League, the double-A Eastern League, and the Advanced-A Florida State League. Only the South Atlantic league, and the offense friendly Appalachian league standout as having similar (.313 BABIP) high marks.

The area where the trend is clearest, is in homerun rate. Take a look at the picture on the right. Each level, from rookie ball to the big leagues, hits home runs at a higher rate than the level beneath it, with one exception-the Appalachian League. The explanation for this is simple, older players inhabit the higher level leagues and older players are stronger and more experienced at picking pitches to drive.

A few other things that I think are interesting. Big leaguers strike out less than minor leaguers, despite facing the best pitchers in the world. The only hitters that struck out less than big-league hitters in 2009 were double-A Eastern league hitters, who are also the only ones to draw walks at a higher rate. Does this lend credence to the argument that AA is better preparation for the big leagues than AAA?

Tags: Daily Recap , Toby Hyde