I've been waiting for someone to do something like this. John Dewan, author of the Fielding Bible and creator of baseball's version of the plus/minus system looked at the -40 his system gave McLouth and decided to break down his play in center to see if a.) he really was the worst fielder in baseball this year or b.) he was worthy of the Gold Glove. It's a really interesting read and Dewan's conclusion is close to the one I came to in August while trying to figure out how to quantify Nate's defense (though mine was mostly based in opinion and his is based on much harder data):
All in all, I no longer think of McLouth as the worst center fielder in baseball. It means something that at least some of the managers and coaches think highly of him. And we see that two areas of his defense are above average: his ability to prevent baserunners from advancing on hits and his ability to make a play above and beyond the ordinary. But we also see that, despite this low error total, he has more than his share of defensive misplays. And the most important aspect of playing outfield defense is covering ground, and McLouth struggles here big time.I really encourage you to read all of his methodology, if only because it's interesting. This is about my opinion of McLouth in center. As I am wont to do, I oversold the "he's a bad outfielder" point of view because I know it's the opposite of what people think. Seeing all of the big numbers in the negative metrics doesn't necessarily mean that McLouth is the worst centerfielder in baseball, but it does probably mean that he's not nearly as good out there as casual fans think. So let's hope McCutchen kills the ball this spring and it's not a problem anymore.
H/T- Bucs Dugout