Instead, McGehee is, at this writing, third in the National League in batting average, sixth in on base percentage, first in hits, and first in singles. It's not all great--he leads the league in grounding into double plays and he's hit only two homers as the Marlins' cleanup hitter--but his 118 OPS+ is second on the team to slugger Giancarlo Stanton. McGehee is a big reason why the Marlins, picked by many to be the worst team in the league, are, well, tolerable, with a 45-52 record that's better than the Padres, Phillies, Diamondbacks, Rockies, and Cubs, and a surprisingly strong fourth in the league in runs per game.
So What's Different? Mostly, it's plate discipline. It's really as simple as that. In 2011, his last year as a major league regular, he swung at 27.4% of pitches outside the strike zone, the 41st highest total among 66 in the National League. That's decent, but not remarkable. This year, only four NL batting title qualifiers have swung at fewer pitches outside the strike zone than his 22.6%. As a result, he's walked in 8.5% of plate appearances compared to 7.5% in 2011, and he's made contact 86% of the time he's swung, compared to 83% in 2011.
And he's been a little lucky. His batting average on balls in play (BABIP) is .369. That's the second best in the NL, where the average is .299. Very high or very low BABIPs are usually not sustainable. McGehee certainly hasn't slowed down at all this year--his slugging percentage has improved every month this year, and he's batting .390 so far in July--but it's reasonable to assume he'll cool off some as his BABIP moves toward a more typical level.
Is It Sustainable? McGehee has cut down on his swing and become more selective at the plate. As a result, he's gone from being a low-average power hitter to a singles-hitting high-average hitter. It's a remarkable transformation. At 31, age will slow him down, and his BABIP will return to Earth, and he's probably not a reasonable choice for a No. 4 hitter. (There are six Marlins with more homers and four with a higher slugging percentage.) So no, he's not a good candidate to finish the year with the third highest batting average and sixth highest on base percentage in the National League. But as comeback stories, his is hard to beat.