Shortly after Arizona traded him to the White Sox before the start 2008 season, Carlos Quentin unleashed a monster season on the American League. Since then, Quentin’s performances have been disappointing to put it mildly. I endeavored to find out what’s different between the All-Star worthy Carlos Quentin of 2008 and below replacement level Carlos Quentin since.
Quentin posted a career best .278 batting average on balls in play during 2008. Coupled with a marked drop in his strikeout rate –what had been 24% the previous season fell to 17%– Quentin saw his batting average spike to up .288. Was there anything systemic that aided the rise in BABIP? It’s difficult to determine. Quentin did hit into fewer pop outs once in Chicago, a feat that dramatically helps to improve one’s BABIP, but we’re not talking about an earth shattering deviation and his other batted ball rates remained fairly consistent.
Furthermore, Quentin repeated the lower infield fly rate in 2009 but saw his BABIP sink all the way to.221. Hitting fewer ground balls in 2009 obviously has an effect but a small one, too small to account for the entire change unless you treat 2008 as an outlier.
Further worsening the drop off from 2008 is a decline in walk rate. It peaked in 2008 at 12% but fell to 8% last season and though it has rebounded to 10% in 2010, his strikeouts are up as well, wiping out the positive growth in walks. Quentin’s newfound penchant for offering more at out of zone pitches is partly a culprit as it has risen from 26% in 2008 to 29% in 2009 and now stands at 31%. It is hard to draw walks when you swing at the pitches that you do get outside the strike zone.
Despite that humongous drop in walk rate and batting average, Quentin still maintains an overall above average hitting line with wRC+s of 104 and 121 after his monstrous 154 in 2008. However his defense, which was never much to write about, has collapsed according to UZR. Without a superstar-level offensive output, the total package is quite lacking and Quentin has totaled up -0.3 WAR since that much heralded Chicago debut year.
Matthew Carruth is a software engineer who has been fascinated with baseball statistics since age five. When not dissecting baseball, he is watching hockey or playing soccer.