Re: Is Heisey now the incumbent?
Heisey is, right now, exactly league average for 2012. (Offense only, as many posters don't believe in defensive metrics.) For his career, he's slightly better than league average in terms of both OPS+ (106) and wRC+ (107). Heisey's WAR is 1.6 this year.
Drew Stubbs has a 67 OPS+. That's 2/3 of the offensive output from a league average player. Offensively, he's below replacement level by a fairly significant margin right now. For his career, Stubbs has an OPS+ of 88, with three straight years of dropping production. (In 2010, he garnered a 105 OPS+. Last season, he was able to put up an 86 OPS+.) In terms of wRC+, it's just as stark a difference between he and Heisey (and Stubbs now v. the Stubbs of three years ago). His wRC+ has decreased from 110 in 2010 to 94 last season to 76 this year. His WAR is 1.2 this year.
Unless you believe the difference in defense and speed is over 25 runs, the choice is fairly clear.
I understand the perception that Heisey is a fourth outfielder. He's never really played a full season as a starter. He's kind of a 'tweener that can play both CF and the corners. He's a hacker that seems to work better either as part of a platoon or as a part-timer. However, if you go by strictly numbers, Heisey actually grades out as a better than league average player, likely to put up around a 3.0 to 3.5 WAR over the course of a full season of at-bats in CF.
Sure, his approach is tough to swallow sometimes, but it's not like he's totally craptastic. When he's been in the lineup, over the course of a full season, he's produced.
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