Infield Flies Killing Andy LaRoche

Andy LaRoche is currently the only player the Pirates received in the Jason Bay trade on the active roster. Craig Hansen hasn’t pitched in 2010, Bryan Morris is in hi-A, and Brandon Moss has a .676 OPS in AAA. Right now, Andy LaRoche is the best hope for the Pirates to get a productive player out of that deal. This year, however, results have been disappointing. LaRoche only has a .311 wOBA this year, down from .324 in 2009.

Much of this decrease in performance can be attributed to a .278 BABIP. Throughout his career, LaRoche has had BABIP issues, most notably in 2008, when he carried a .190 BABIP through a relatively large sample of 186 balls in play. The key to these issues appears to be a penchant for hitting infield fly balls. In 1100 career plate appearances, LaRoche has an IFFB% of 14.5%. That would rank in the top 10 marks among qualified players in 2009.

It should be obvious that infield flies are a bad result. The BABIP on infield flies is right around .010. Even though LaRoche’s 35.0% career fly ball rate is below average, his high IFFB rate still means that 5% of his batted balls are almost guaranteed to be outs.

That problem has only been exacerbated in 2010. LaRoche’s infield fly fate has expanded to 25%. With a quarter of his fly balls going for outs, and his fly ball rate up to 36%, that means that 9% of his batted balls are guaranteed outs. That’s put a major damper on his slugging percentage this season – his SLG has fallen from .401 to .364, and his ISO has seen an equivalent drop. His ground ball BABIP has increased to .233 from .218 (and a bewildering .111 in 2008), which has offset the damage to his batting average and on-base percentage.

Really, the only major difference between LaRoche’s 2010 and 2009 is this increase in infield flies. His walk rate is within 0.1%, his HR/FB rate is within 0.5%, and his strikeout rate is actually down 2%. It’s nearly impossible for an infield fly rate this high to be sustainable – no qualified player in 2010 hit more than 17.6% of his fly balls in the infield. Expect LaRoche to start hitting more of his fly balls out of the infield. Both his power and batting average will increase as a result, and his line should approach, if not eclipse, last year’s 97 wRC+, 2.6 WAR season.