Defensive Metrics

Apparently through the first two weeks plus of the baseball season, Mets second baseman Brad Emaus is tied for third in the league at his position in Ultimate Zone Rating, one of the fancier fielding metrics. Yeah. Okay. I've watched really seriously most of the Mets games so far this season. He's not good. He's fumbled more than one simple double play ball, one of which led rather directly to one of the Mets' crushing losses to the Rockies. I'm pretty sure he's messed up other plays, too. And I can't recall seeing him make very many spectacular plays where he got to a ball you never expected him to catch, or made a really strong throw where he needed to spin and fire right on the money to get the guy by a tenth of a stride, or whatever. He seems kind of mediocre. I've seen Daniel Murphy make a couple of distinctly plus-level plays, and I don't think I've really seen him messing up at all, and apparently UZR likes him less well than it likes Emaus. My overall conclusion is that UZR is not very good.

One thing I have noticed is that a whole lot of balls have been hit at Emaus. Ground balls to the second baseman  have been fairly common. Since one major component of a lot of fielding stats is "range," which is defined as plays per inning, obviously that's going to give him an inflated rating. That's part of why I think defining range in terms of number of plays made is a dreadful way to go, because players don't all face the same dispersion of batted balls. The Mets, over the past few years, have conventionally been a fly-ball team, which leads to Jose Reyes getting somewhat below-average numbers of plays, thus hurting his performance on the fancy metrics. Okay. He's still a brilliant defender with outstanding range, in the actual real-life meaning of "range." So these metrics are fundamentally missing the point, at least to some degree.