Here's Casey McGehee as a minor leaguer:

Minors (2836 PA): .279/.332/.409; 75% BIP, 1.9 HR%, .316 BABIP

AAA (1153 PA): .282/.334/.410; 75% BIP, 2.1 HR%, .313 BABIP

2009 (394 PA): .301/.360/.499; 70% BIP, 4.1% HR, .330 BABIP

Two notes: (1) if someone could double check my BABIP math on McGehee's minor league stats, that'd be awesome. I've calculated it about 4-5 different times, and .316, .313 don't look right. (2) If someone could point me to PCL park factors, that'd really be helpful. I can't find 'em.

Now, here's the problem: A 26-year old high-contact hitter (75% minor league BIP rate) comes to the majors and in a neutral offensive environment doubles his HR% and suddenly puts the ball in play 5% less frequently (huge shift!) as a result (he also increased his BB%), while collecting hits on balls in play nearly 2% more frequently (huge shift!) and 4% above average league defensive efficiency.

Now, even without minor league records, that season looks flukey; somehow, a clunker like McGehee was able to beat defenses by 4% on balls in play, while also nearly doubling the league average HR% -- without collecting an overly high K% or BB%. With minor league records we can see that McGehee's HR rates were completely out of the norm in 2009, completely out of nowhere, alongside his BABIP shift (in a neutral offensive environment!) and BIP% rate.

Just think about this for a second: McGehee managed to put the ball in play significantly less frequently while collecting hits on those BIP notably more frequently, all the while doubling his HR% and increasing his BB%. Of course, he did this as a 26-year old rookie, with absolutely no MLB playing time to ramp up to his prime years or anything like that.

Does that scream "I will regress for 2010" to anyone else? (That's why I say trade McGehee now. He's served his purpose, proven Melvin can still pull 'em off the scrap heaps, and now it's time to turn him into a trade piece).

***

Here's what McGehee's corrections look like (I've kept the walks, correcting only the BABIP and HR, and therefore the BIP%):

League average efficiency: 400 PA, 288 BIP; .299 BABIP, 86 BIPH; 8 HR, 32 BB, 70 K, 2 HBP; 366 AB, 94 H, 22 2B, 0 3B, 8 HR; .257/.320/.383