At the margins

Commenter Jim H writes of yesterday's post:

Defensive metrics are often very misleading especially at the margins. There are of important defensive attributes that either not measured by defensive metrics or not measured very well by them. Throwing, positioning, taking good routes, just making the plays you should make, are all things Hunter can still do.  Playing half of his games in a park that doesn't require great range will help as well.

Which is, simply, wrong. Let's take those four sentences in reverse.

Playing half of his games in a park that doesn't require great range will help as well.

Target Field is one of the more spacious outfields in the majors, particularly in the gaps. It does demand range from the corner outfielders.

Throwing, positioning, taking good routes, just making the plays you should make, are all things Hunter can still do.

If he is still doing them, where are the plays? They are going unmade. That's the conclusion of plus-minus (Hunter was -28 in 2014, -38 for 2012-14); of runs saved (-18 in 2014, -13 for 2012-14); of total zone fielding runs (-17 in 2014, -22 for 2014-14); ultimate zone rating (-18.3 in 2014, -11.2 for 2012-14) ... all different systems, all coming to the same conclusion. He's bad, and he's getting worse. 

There are of important defensive attributes that either not measured by defensive metrics or not measured very well by them.

If he's positioning himself better than other right fielders, he's still not making the plays. If he's throwing better than other right fielders, he's still not nailing base runners or making them hold their base. These are things the metrics include, perhaps imperfectly, but more accurately and objectively than the eyetest.

Defensive metrics are often very misleading especially at the margins. 

If Jim H is talking about playing time margins, he's right on one end (the lack of playing time, as exampled in Thursday's post by Danny Santana and Eduardo Escobar.) The more playing time, the more accurate the metrics figure to be. That's the playing time margin Hunter occupies.

If he's talking about the best and the worst rating, he's just wrong. That's where the action is.

There is a margin of error in all this. Let's say, just for the sake of argument, that the margin of error is three runs per 1,200 innings. A dead-average outfielder scores at 0. So he might be as good as +3, he might be as poor as -3, but he's in the middle.

Hunter's not there. Hunter's at -18. Maybe that overstates how bad he is by 3 runs. So he's minus 15 instead, Big whoop. He's still awful. There's just as good a change that he's really minus 21, which is even worse.

Hunter's metrics are, or should be, compelling precisely because he's on the outer edge.