A Quick Defense of Matt Williams

On Saturday night, Matt Williams removed Jordan Zimmermann with one out to go, trying to preserve a 1-0 lead. Drew Storen entered immediately gave up a single to Buster Posey and a double Pablo Sandoval, tying the game at 1-1; the Giants would go on and win in 18. Williams was heavily criticized in the aftermath of the game for taking a pitcher out who was, at that, throwing a shutout, especially given that he had only thrown 100 pitches on the night.

But let’s just look at the numbers here for a second. We’ll look at career and 2014 batting against both pitchers.

Career	BA	OBP	SLG
Zimmermann	0.249	0.292	0.383
Storen	0.224	0.289	0.330

2014	BA	OBP	SLG
Zimmermann	0.244	0.277	0.354
Storen	0.210	0.262	0.278

On a per-batter faced, Drew Storen has been a more effective pitcher than Jordan Zimmermann. This shouldn’t be a big surprise, since good relievers are almost always the hardest guys in all of baseball to hit, and Storen is a very good reliever.

And as you’re probably sick of reading about by now, pitchers get worse the more often they face the same hitter within the same game. Here are Zimmermann’s career splits by times through the order:

Split	PA	BA	OBP	SLG
1st PA	1,304	0.226	0.273	0.355
2nd PA	1,291	0.256	0.293	0.389
3rd PA	982	0.262	0.313	0.407
4th PA	81	0.338	0.363	0.468

The first time Zimmermann faces a hitter in a game, he’s lights out. Second time, still pretty good. Third time, he’s roughly league average. The fourth match-up has been a disaster for him.

And yes, Zimmermann was throwing the ball well on Saturday night, but you only get to face a guy a fourth time through the order if you’re pitching well, so that entire data pool is essentially comprised of performances against Zimmermann late in games in which he had already performed at a high level. 81 plate appearances is of course a small sample, but both the league-wide and Zimmermann-specific trends are clear; his performance declines the longer he stays in, and by the time a hitter has already faced him three times, they hit him pretty well.

Even if we cherry pick the numbers, we can’t come up with a scenario where the expected line against Storen would be worse than against Zimmermann. Storen’s career .273 wOBA allowed is better than Zimmermann’s career-best .280 wOBA allowed this year, so even if we give Zimmermann credit for his 2014 performance and still hold Storen’s entire career line against him, Zimmermann still loses out. Add in any kind of times-through-the-order penalty and it ceases to even be remotely close.

Storen was the right call. It didn’t work, but that doesn’t make the move a mistake.