Dustin Pedroia's 2013 was fantastic, but it's hard not to look at his line and think that maybe it could have been even better. That's not a knock on Pedey so much as it's a reminder of how immense his talent is: In a year where he batted over .300, led the American League in plate appearances, finished 10th in the league in on-base percentage, and deservedly won a Gold Glove at second, he could have done more.
Specifically, Pedroia could have hit for a bit more power. He slugged just .415 on the year, giving him a career-low .114 Isolated Power (slugging percentage minus batting average, in order to measure the power behind a batter's hits). In the three previous seasons, Pedroia had combined for a .172 ISO, and came in to 2013 with a .158 career mark. So, what happened?
You might recall that Pedroia played all of 2013 with a torn ulnar collateral ligament in his thumb, suffered on Opening Day when the second baseman slid headfirst into first. Pedroia would only miss two games after doctors told him his play was up to his threshold for pain, but it's entirely possible that, even with Pedroia's tolerance for the injury, it sapped him of some of his power. This is not the only explanation, though.
Pitchers attacked Pedroia far differently in 2013 than they had in the past. Our own Matt Sullivan noticed as much in late-May, when he discovered opposing pitchers were pitching outside to Pedroia even more frequently (and desperately) than they had in the past, and the Providence Journal's Tim Britton wrote up this occurrence as well. It's a sound strategy, as Pedroia's power is almost entirely on the inside part of the plate, and, as Sullivan states, it takes "a max-effort stroke" from Pedroia to hit a ball into the stands even when it's in his zone. If a pitcher can keep the ball away, they can avoid the homer more often than not.
We can see what his year-end results looked like, in the same PITCH f/x form that Sullivan used to elaborate on the subject in May. First, Pedroia's ISO in various zones, from the catcher's point of view:
Up-and-in, inside and down the middle, and low and well inside were Pedroia's only significant spots for power in 2013, with Pedroia barely able to muster any real pop on the outside of the plate, or even through much of the middle. However, if we look at his batting average on balls in play in the same kind of chart, we can see that he still got his hits in regardless:
The problem for pitchers, besides the above lofty BABIP all over the place, is that the opposition then gives up walks to Pedroia by aiming on the outer part of the plate. If it's not a walk, it sets Pedroia up to poke the ball the other way if it's close enough to get his bat on. Pedroia's wrists are just too fast and powerful to be fully limited by pitchers changing up their strategy against him, especially when he shortens his swing for contact purposes, rather than trying to crush everything. They can limit his homers, but can never truly stop him, not so long as his bat speed and eyes are what they are.
If pitchers won't give Pedroia pitches on the inner part of the plate any longer -- at least, not on purpose -- he's still going to be hugely valuable, as he was in 2013. He'll be just 30 years old this season, and his preparation and hard work are two of the reasons the Red Sox extended him through 2012: they know he's going to push himself to stay on top of his game, even as he ages and his natural skills fade. The 2013 season was already an example of Pedroia evolving to succeed with what the game was giving him.
With his thumb healed -- and Pedroia officially retiring his reckless headfirst slides into first base following 2013's injury -- we might see his power trend up again. He's not going to start going over the wall on balls hit the opposite way with regularity or anything, but maybe a few of his balls in play become doubles again, with another homer here and there, thanks to a healthy hand gripping the bat, and less focus on an intentionally shortened swing. If pitchers continue to keep things outside against Pedroia, however, his power is only going to climb so much. So long as he continues to approach his plate appearances the way he has, though, his production should be of no concern.