Before the season, it appeared that Jack Cust‘s career with the Oakland Athletics was over. After a relatively unimpressive 2009 campaign (.342 wOBA, 0.9 WAR, 612 PAs), the A’s designated Cust for assignment at the end of Spring Training. Cust went unclaimed and seemed destined to rot in AAA Sacramento. But the Eric Chavez project ended as a complete failure (.268 wOBA in 123 PAs), resulting in Cust’s return to Oakland.
Cust’s return has been a rousing success. He’s still not making contact often (38.2% K/AB), but when he does, he’s making things happen. Entering play yesterday, Cust had a .267/.391/.436 slash line, and he added a 2/4 game with a HR against the Indians last night. With that home run, Cust has only 10 home runs in 278 plate appearances – not bad for the typical player, but Cust hit 84 HR in his first three MLB seasons. The low home run total marks a bit of a decline for Cust, and we can see that in his ISOs: .248, .245, .177, .169 from 2007 to 2010.
Despite this power drop, Cust’s 2010 wRC+ of 134 compares well with 144 wRC+ in 2007 and his 132 wRC+ in 2008 largely because Cust is having a remarkable amount of success on balls in play. His .386 BABIP is the highest mark of his career, besting the .355 mark which helped power his career year of ’07 and his solid career mark of .334. Naturally, this is a huge reason why Cust’s line looks as good as it does. My four factors method would project Cust’s line at a slightly above average .335 wOBA with his career .334 BABIP. If Cust’s average were 52 points below his career average instead of 52 points above, the method predicts a .303 BABIP, right around replacement level for a DH.
It shouldn’t be that surprising, however, that Cust is seeing relative large fluctuations in his BABIP, as he quite rarely hits the ball in play. In fact, the only player to put the ball in play less often this year is Mark Reynolds, whose 46.2% BIP rate is the only one besides Cust to be under 50% this year among players with at least 200 platte appearances. Reynolds is actually seeing the opposite kind of variance to Cust, as Reynolds’s .279 BABIP is 51 points below his career BABIP. Here is a spreadsheet with these BIP rate numbers for the whole league to date in 2010.
BABIP is a fickle beast, and the fact that players such as Cust see even fewer balls in play than the average player makes it even more prone to wild fluctuations. This season, Cust is the benefactor. Next year, though, the A’s might get more of a 2010 Mark Reynolds BABIP than what they’ve seen from Cust this year, and then Cust may come crashing down to Earth if his former power doesn’t return.