Pena The Cubbie

First baseman Carlos Pena revived his career in Tampa, transforming from a disappointing former top-10 draft pick who passed through Texas, Oakland, Detroit, the Bronx and Boston to an offensive force. From 2007-2009, Pena had a .252/.382/.553 batting line, with a .393 wOBA that tied him with Miguel Cabrera for 14th among qualified MLB hitters over that time frame.

Unfortunately, Pena’s free agent walk year wasn’t near as impressive: the lefty masher hit .196/.325/.407 in 2010, and his wOBA nosedived to a career-low .326. That’s a solid number for a slick-fielding shortstop or center fielder, but hardly sufficient for a player at a power position. The Chicago Cubs recently signed Pena to a one-year, $10 million deal, hoping that the 32-year-old keeps the Bleacher Bums at Wrigley busy with a bounce back performance.

What caused Pena’s quiet year at the plate, and is he primed for a comeback in Chicago? Let’s try to find out.

Pena’s plate patience wasn’t a source of concern, as his 26.6% rate of swinging at pitches tossed out of the strike zone was well below the 29.3% big league average. Not going all Francoeur at the plate leads to hitter’s counts. According to Baseball-Reference, Pena got ahead in the count against pitchers in 42.8% of his plate appearances. For comparison, the 2010 American League average was 35.5%. It’s no surprise, then, that Pena walked in 14.9% of his PA. Among qualified batters, only Daric Barton and Prince Fielder took a leisurely stroll to first base more often.

However, while Pena remained a walk machine, his power declined. A .211 Isolated Power is hardly poor, but that figure was well below Pena’s previous work with the Rays: a .345 ISO in 2007, .247 in 2008 and a .310 mark in 2009.

Pena rarely hit a ground ball during his first three years in Tampa, but that changed this past season. He grounded out just 33% from ’07 to ’09 (44% MLB average). In 2010, he chopped the ball earthward 44.9% of the time. That spike in worm burners certainly didn’t help Pena’s power output. Based on Pitch F/X data from Joe Lefkowitz’s website, here are Pena’s ground ball rates by pitch type since 2008 (the first year for which the site has data). To provide more context, I also included MLB ground ball averages by pitch type from The Hardball Times’ Harry Pavlidis:

Pena saw an across-the-board increase on grounders, hitting more breaking and offspeed stuff into the dirt than the average MLB batter. His grounder rate on fastballs, though still below the big league average, shot up considerably as well.

Pena has long been a dead pull hitter, sizzling many of the balls that he puts in play to the right side…

…and many of those extra grounders came on pulled pitches. Those power-sapping ground balls, coupled with a very low BABIP, made Pena a lousy pull hitter this past year:

From ’07 to ’09, Pena was a prodigious pull hitter. According to our new expanded splits section, his .555 wOBA when pulling over that period was sixth-best among big league batters. But this past year, his wOBA to the right side of the field was a full 40 points worse than the average lefty batter.

Pena’s performance when hitting to center also suffered compared to past years, with more grounders, less pop and a lower BABIP:

He fared very well when putting the ball in play to the opposite field, but keep in mind he rarely goes to the opposite field:

With few hits falling to the pull side and to center, Pena’s overall BABIP nosedived to .222. From 2007-2009, Pena’s BABIP was .283.

Pena, of course, is often subject to a defensive shift that moves fielders more toward his pull side. Over at The Baseball Analysts, Jeremy Greenhouse did find that shifted hitters on the whole have a lower BABIP than non-shifted hitters, and that Pena’s ground ball angle (he hits lots of grounders toward the second baseman) is particularly shift-worthy.

But, while there’s little reason to expect Pena’s BABIP to approach .300, it’s also unlikely that it will remain over 50 points below his career mark. His batting average is never going to be pretty, but he’s more apt to hit in the .230s-.240s next year than below the Mendoza Line.

The key for Pena is to keep the ball off the ground. Those ground balls hurt his power numbers, and they’re especially damaging for a slow-footed slugger subject to a defensive shift.

Happily, he is moving from a park that damages lefty power to one that boosts it considerably — according to StatCorner, Tropicana Field depresses HR production by 11 percent compared to a neutral park, while Wrigley pumps it up by 19 percent. There’s little chance that Pena produces like he did during his peak years in Tampa. But with better luck and a more favorable offensive environment, Pena’s triple-slash could look an awful lot like his career averages: .241/.351/.490. Maybe not “Holy Cow!” worthy, but not bad either.

How do you think Pena will fare in Chicago? Make sure to submit a 2011 projection here.