A.J. Pierzynski may be in the midst of the worst season of his career, and at age 33 it's hardly surprising.
Argue all you want about Pierzynski being great at handling a pitching staff. That's a fine quality for a catcher to have. Unfortunately for Pierzynski, it appears to be the only positive quality he brings to the White Sox.
Through 100 plate appearances, Pierzynski is the 25th-worst hitter in baseball as gauged by wOBA. Yes, there are three Sox players worse than him—Alex Rios, Gordon Beckham and Juan Pierre—but I'd expect at least Rios and Beckham to finish 2011 with better offensive campaigns than Pierzynski.
At 33 years old, Pierzynski has reached that age when most catchers start to break down. Pierzynski has caught 11,302 innings in the major leagues—at some point, that's going to take its toll. We saw it start to have its effects last year, when Pierzynski's slash line dropped to .270/.300/.388, down from his career average of .284/.323/.422. This year, Pierzynski's slash line sits at .258/.286/.312.
Usually, a one-year dropoff after years of offensive consistency isn't a big cause for concern. But that generally applies to players in their prime, not catchers who are past it. Furthermore, this is the same A.J. Pierzynski who never had an OBP higher than .333 since leaving Minnesota after the 2003 season. That's not the mark of a good offensive player, more the mark of a mediocre one.
Give Pierzynski credit, though—he has worked to change his approach as his body has aged the last few years. He's doing everything he can to put the ball in play, as he's made contact on 91.8 percent of pitches he's seen this year. He's swinging and missing at about one in every 20 pitches. But, unfortunately for him, the strategy hasn't helped. It's led to an increasing ground ball rate that's nearly touching 50 percent. A lot of those groundouts have been weak to his pull field—the Pierzynski groundout to second has become a staple of his offensive game.
Making matters worse is that Pierzynski's defensive ability continues to decline. It wasn't great in the first place, but this year it's been downright unacceptable. Opponents have tried to steal 18 times off Pierzynski, they've been successful 17 of those times. All 14 runners who have attempted to steal second base have been successful. And he leads baseball in passed balls (three, which is in a very small sample size).
Not all those stolen bases are Pierzynski's fault—pitchers like Gavin Floyd are notorious for how poorly they hold runners on—but at some point, when your catcher is throwing out 6 percent of baserunners, your catcher is at fault. Opponents know it's open season to run on Pierzynski, and he hasn't given them a reason to stop trying yet.
For the record, Pierzynski isn't this bad. He won't finish 2011 with an OPS below .600, and he'll throw out more than 6 percent of baserunners. But those expected regressions from early-season stats shouldn't be expected to be too significant.
What the White Sox have in Pierzynski is a formerly-serviceable catcher who appears to have reached that age where 11,000+ innings of squatting behind the plate have caught up to him. There's nothing Greg Walker can do about that, folks.