Just like last year, we'll be grading all the Tigers who contributed significant playing time over the course of the season, starting with the position players, then doing the rotation members, and finally finishing up with the bullpen and writing profiles for players without enough playing time to earn a grade. Each list will run in alphabetical order. These reviews will occasionally dip into sabermetrics so we can get a better idea why things happened, but I'll try to explain as we go through things.
I must admit, Jhonny Peralta's season was a bit of a surprise. It's not that he hadn't hit well in the past. He had. It's not that he was an awful shortstop in the past. (Unless you ask Cleveland, anyway.)
Odds were just not in favor of a 29-year-old Peralta recapturing his youth at the level he did. His batting average (.299) was a career high. His OPS (.824) was the second-highest of his career. His wOBA (and weighed Runs Created) were the second best of his career. His strikeout rate was the lowest of his career.
What about fielding? His UZR (9.9) was easily the best of his career and among the top three in the American League. (However, if you look at Defensive Runs Saved you'll find a totally different story: -4 compared to the average shortstop.) That's kind of an extreme disagreement in stats. But in any case, Peralta did the job without looking bad at the position.
So in the end, you have to credit him for a wonderful 2011 season, but you've got to be cautious about expecting a repetition of that season next year.
At the plate:
Peralta compares quite favorably with his fellow shortstops. He finished fourth in average and slugging average (.478) in the MLB, and seventh in on-base percentage (.344). He was fourth in home runs (21). Go a bit more hardcore sabermetric and he was third in wOBA (.353).
One of the big differences in Peralta's batting game was a decrease in ground ball rate and an increase in fly balls. So while his home run per fly ball rate basically stayed level, the increase in fly balls meant he hit six more home runs. He actually hit fewer doubles than in recent years, and he remained on the very low end of triples. But he saw his ISO jump up thanks to the home runs.
Meanwhile, he managed to turn contact into a lot more hits than in recent years. His BABIP of .325 sounds repeatable enough, but we should note his xBABIP was .299. (Blame the flyball rate for that. He did get his line drive rate up to 22%). So there may have been some luck in there.
In the field:
Like I've frequently said, fielding metrics are hard to use. You don't want to rely on any single one too much, and their level of disagreement makes you really wonder about any of them. But they're what we've got. So Peralta finished fourth in UZR/150 games (10.7) among major league shortstops who played at least 1000 innings this year. However, his -4 rating in Defensive Runs Saved would indicate a below-average season compared to his peers. We can say this much about him at the minimum: He didn't make many errors. Peralta's .989 fielding percentage (another flawed defensive stat) was the best of his career.
I don't know that we're going to see a huge drop-off in Peralta's numbers. It's not like he was a guy who couldn't hit and suddenly discovered how. He was a guy who could hit and who seemed to get stuck in a funk for a couple of seasons who rediscovered his stroke after being traded to Detroit.
However, I'd advise caution on having expectations too high. Peralta might be an above-average hitting shortstop overall, but numbers somewhat like 2007 and 2008 might be more reasonable to expect. So I'll say a 275 average, .335 OBP and .450 slugging is a good starting point.
As for his glove, I don't think we'll see a remarkably different player. I don't think he's as good as his UZR said he was this year, but he seemed to make the plays he needed to just fine and that's good enough for me.