Seeing Defense

Joe Posnanski teams with Tom Tango to compare the fans scouting report on defense (the eyeball test) to the numbers computed by advanced defensive analysis:

So we compared them player for player from 2011-17. And in roughly 95 percent of the cases, the fans scouting report matches up stunningly well with DRS, UZR or both.

Let’s repeat that: The eye test and the defensive numbers almost always are very close. Tango and I looked at the years 2011-17 to get a larger sample size, and the agreement between eyes and digits was pretty staggering. We’ve been led to believe because of a few examples that the numbers and the eyes see defense in entirely different ways, and it just isn’t true.

It turns out that two players the fans overrate compared to the numbers are Mike Trout and Eric Hosmer:

Well, it could be the numbers are wrong. Hosmer’s greatest skill, by nearly unanimous opinion, is his hands. One theory is that he’s as good as anybody in baseball at saving infield errors by scooping bad throws out of the dirt — again and again people say that he saves 20 to 50 errors a year with the slickness of his glove — and the numbers don’t pick that up.

But is this true? Probably not. If Hosmer was really saving so many errors, wouldn’t this show up in his teammates’ defensive numbers? Wouldn’t we be able to see this in, say, a substantially lower error total for third baseman Mike Moustakas and shortstop Alcides Escobar? But it doesn’t seem like that’s true. Escobar finished tied for the most in errors in the AL in 2012, when Hosmer was 22, and you would think at the top of his defensive powers, and he’s been in the top five in errors two other times. Moustakas has been top five in errors as well.

And Hosmer has been top five in errors among first basemen five times. I don’t like errors as a statistic and feel lousy for using it, but errors are useful here because they are part of the eye test. People who want to say that Hosmer’s advanced numbers miss something have a harder time explaining why he makes quite a few errors.

The whole article is an interesting read.

from baseballmusings.com http://ift.tt/2Fki3uZ