Is Curtis Granderson Slipping?

Much was expected from Curtis Granderson last year. After re-tooling his swing in 2011, Granderson turned in an MVP-caliber season. The biggest addition to Granderson’s game was his sudden power against lefties, which had plagued him up until that point in his career. While he managed to retain those gains, and actually hit more home runs in 2012, his slash line fell to .232/.319/.492. Granderson will turn 32 next March, which is an age where many players start seeing decline. Can Granderson stave off the inevitable just a bit longer?

Granderson is a safe bet to improve on his .260 BABIP, which means his overall numbers should see a bit of a rebound. But there were plenty of reasons for concern about Granderson’s numbers that cannot simply be written off as luck. One of the biggest problems was his strikeout rate, which jumped by 4 percent. Granderson was already a player whose strikeout rate was just high enough for him to still post solid numbers, so jumping to 28.4 percent is tough to swallow. As Adam Dunn, Chris Davis and Pedro Alvarez can attest, there’s still some value in striking out in nearly 30 percent of your plate appearances if you can hit for monstrous power, but it’s a dangerous line to walk.

Perhaps more troubling is how dependent Granderson has become on the long ball. Many of his at-bats seemed to end with an all of nothing outcome. Either he made contract and went yard, or he missed the ball completely. Granderson’s contact rate, specifically on pitches in the strike zone, fell from 88.1 percent to 81.0 percent last year. That doesn’t necessarily mean he’s finished, as some talented hitters can succeed in spite of low contact rates, but it’s not especially promised when coupled with his rising swinging strike rate.

While that combination of factors seems to suggest that maybe Granderson lost some bat speed last year, that’s not immediately evident when looking at his pitch value data. Granderson was still effective against fastballs, just not to the same degree as last year. In fact, the PITCH f/x data suggests that Granderson was better against all type of fastballs last season than he was with off-speed stuff. Granderson actually struggled with off-speed pitches, particularly curve balls and change ups. He managed to be just barely above average against sliders, which, for him, was a slight decline from 2011. It could be that Granderson was going up to the plate looking to hit fastballs, and wasn’t able to adjust as easily to slower pitches.

That puts Granderson in a bit of a murky situation heading into next season. He did see some age-related decline, and may have been too dependent on hitting fastballs, but a BABIP rebound still ensures his overall line improves. There’s a chance those two factors offset, and Granderson is able to succeed in spite of a declining skill set. But watch him numbers closely next year. If his high strikeout rate and inability to make contact continue, there will be justified reasons for concern.