Pete Crow-Armstrong and the Generosity of Enemies

[Matthew Trueblood]

Image courtesy of © Patrick Gorski-Imagn Images

Offensively, it's been an uneven start to the season for Pete Crow-Armstrong. He's batting .241/.307/.362, even after a torrid road trip to Los Angeles and San Diego. As we've discussed multiple times, he's gotten ever-so-slightly more patient this season, which has led to more walks, but he's also striking out more, and he didn't get his swing calibrated well enough to produce his usual power until this weekend, when he hit his second and third homers of the year against the Padres.

Something else happened in San Diego, too, though. For the first time all year, an opposing player challenged a called ball against Crow-Armstrong. The Padres lost that challenge, and Crow-Armstrong eventually drew a walk, but finally, someone actually challenged a call on him.

It might seem unsurprising that the free-swinging Crow-Armstrong is relatively unimpacted by the advent of ABS, but the stats say he should have been more affected. According to Baseball Savant's ABS Leaderboard, opponents should have challenged roughly five times against him by now, winning three of them. The only qualifying hitter with a bigger difference between the rate at which opponents should have challenged them and the rate at which they've actually done so is the Rockies' Troy Johnston.

Lots of times, this year, the Cubs' star outfielder has taken pitches on the very edge of the zone; watched them be called a ball; and gotten a reprieve from an opposing catcher who was either otherwise occupied, insufficiently confident in the pitch they'd just caught, or unwilling to risk losing a challenge on the rare take by an exceptionally aggressive hitter.

This is a good example of the first of those means of escape from a challenge and an overturned call. With the runner going, the catcher's focus moved to making a throw, and he wasn't sure enough that the pitch he'd caught was a strike to issue a challenge on the non-call. Other times, the situation in which Crow-Armstrong took a borderline pitch isn't high-leverage enough to warrant a challenge. He gets away with one, because he's taking a pitch in the right situation to do so.

Sometimes, multiple things are happening at once. The league is likely to arrive, eventually, at a mutual understanding whereby players don't challenge often in games that aren't close late, like this one. Early in at-bats, that goes double. But the fact that Crow-Armstrong squares to bunt and that the catcher is again distracted by baserunners has something to do with the non-challenge, too.

Those little qualifiers and mitigating factors can't explain away everything, though. Statcast's 4.9 expected challenges for Crow-Armstrong is the product of a probabilistic model. In truth, opponents have had a whopping 18 reasonable opportunities to challenge, and by my count, 11 of those were actually strikes. Some of those, inevitably, came in important situations and/or leverage counts, where it's quite clear that the catcher should have tapped their head.

Is that non-challenge a product of undue timidity, or did the Pirates just not realize that pitch found the corner? One way to answer that is by looking at another, very similar instance.

With the bases loaded and two outs in a close game, even a 0-0 pitch is a high-leverage one. Oyster Analytics's model for assessing challenge decisions says the Phillies should have challenged even if they thought they were just on the wrong side of a coin flip here; the actual pitch location should have given them roughly a 65% confidence level.

Ok, here's the twist: this isn't actually a Pete Crow-Armstrong issue. I mean it is, but in another way, it isn't. This year, a recent trend toward fewer strikes being called on the outer edge of the zone to lefties has accelerated. Roughly 15 years ago, one of the pernicious little problems the game faced was a strike zone that bulged weirdly off the plate for lefty batters. Now, strangely, things have almost tipped the other way. Umpires are calling fewer strikes than they should on the outside corner—and on the inside corner, to righties. The called strike rate on takes on the third-base edge of home plate has plummeted.

To his credit, though, Crow-Armstrong has responded in the rational way to this change in the state of play. He swung at over 63% of the pitches he saw in the three Shadow zones along the outside edge of the plate last season, according to Statcast. This year, that number is under 50%. This is where his extra walks are coming from. He's getting help, to draw them, because umpires should have called a fistful of extra strikes, and (failing that) catchers should have challenged and won a few of those strikes, anyway.

It's not quite luck, though, because the zone's shrinkage is a structural reality of the game this year. Crow-Armstrong has made the right adjustment to suit that. It shouldn't be working quite as well as it has, and he needs to keep adjusting, but swinging less at pitches on the fringes of the zone is a good thing, especially for the often hyper-aggressive Crow-Armstrong. His opponents are likely to stop going so easy on him soon, but now that his swing is back online, he won't need that help as much, anyway.

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[Ruxskull]

Could another reason be that Catchers understand PCA is a free swinger and risking a challenge on him is not worth it since he is likely to swing at the next bad pitch anyway?

I figure catchers and managers discuss these sort of things, who do make challenges against and who not to. 

And of course, It’s still early. Maybe hold off on more definitive conclusions until the All Star Break.,

P.S. and given how well and near seamless the challenges work, I think using ABS all the time should be considered. Take the new fangled tactics of challenges out of it and let MLB have a more accurate calling of balls and strikes on all pitches.