Meatballs, With a Chance of Clouting

“He made a mistake, and Trout made him pay.” No doubt you’ve heard some version of that sentence countless times. Maybe the announcers called it a hanging slider, or a meatball, or any number of other ways of describing a poor pitch. But what exactly does it mean, and how can you know one when you see one?

I’ve discussed that question with my colleagues frequently, but we’ve never come up with a satisfactory answer because the pitches that get classified as mistakes aren’t always intuitive. Sometimes a pitcher hits the inside edge of the zone, only for a hitter sitting on just such a pitch to unload on it. Sometimes a backup slider ties up the opposing hitter. There’s bias to these observations, too: You’re far more likely to remember a pitch that gets clobbered for a home run than one that merely results in a take or a loud foul.

I still don’t have a definitive answer. I did, however, make an attempt at answering one very specific form of the question. One pitch that really does feel like a mistake, regardless of intent and irrespective of circumstance, is a backup slider over the heart of the plate. Spin a slider wrong, and it morphs into a cement mixer, turning over sideways without movement. Leave one of those middle middle, and the result is a slow and centrally located bat magnet.

Conveniently enough, that’s easy to define. I looked for every pitch thrown in 2022 that fit a number of criteria. First, it had to be a slider. Second, it had to have horizontal and vertical movement (excluding gravity) 20% lower than average for the pitcher who threw it. In other words, it had to break meaningfully less than that pitcher’s intended pitch. Finally, it had to be in the middle of the strike zone. I defined that as being in the middle third of the strike zone both horizontally and vertically.

By those definitions, there were 464 meatball sliders thrown in 2022. That’s fewer than you might expect, but it’s a pretty exacting set of requirements. Plenty of mistake-y pitches match some but not all of my criteria. Maybe they had more vertical movement than expected, or were mid-height but too close to one of the sides of the plate. These aren’t mistake-ish pitches; they’re extreme mistakes. I’m willing to bet that nearly none of them were thrown on purpose. Here’s one:

By aggregating these pitches, we can say a few things right away. First, don’t throw them! As you might expect, batters perform quite well on them. They managed a .441 wOBA when putting the ball in play, with a .329 batting average (and thus BABIP) and a .682 slugging percentage. That’s excellent production. It’s meaningfully better than how well batters do when they swing at pitches right over the heart of the plate (.346 batting average, .607 slugging percentage, .403 wOBA).

We can go a little further, even. The archetypical hanging slider gets launched for a home run. That’s borne out in the data: when batters put these hanging sliders into play, they homered on 7.9% of their batted balls. That’s again much higher than the home run rate on all pitches over the heart of the plate (5.7%).

But bad news for people who believe in fate: these pitches aren’t destined to get crushed. If 7.9% of batted balls on “mistakes” are hit for home runs, that means 92.1% aren’t. That doesn’t even account for foul balls, called strikes, or – god forbid – swinging strikes. As it turns out, plenty of these mistake pitches result in strikes. Nearly two-thirds – 64.7% – of low-movement, dead-center sliders end up as either foul balls or strikes.

Do batters make more contact against Sonny Gray’s bane? They sure do. Batters whiffed only 12.1% of the time when they swung at these crappy pitches. For pitchers, that’s an awful result. Batters come up empty more often when swinging at sinkers, the easiest pitch to make contact with, than when swinging at meatballs. Batters fouled off a further 38.5% of them, not counting foul tips. That’s close to the overall average foul ball rate; apparently what kind of pitch you swing at doesn’t say much about how likely you are to hit it out of play.

All of these numbers underscore a point that is really hard to explain: the difference between a good slider and a mistake pitch is a difference in degree, not kind. Batters hit 2.8 home runs for every 100 meatball sliders they saw in 2022. For all sliders overall, that number was 0.7. They hit 3.8 homers per 100 swings against meatballs; for all sliders, they hit 1.5 homers per 100 swings. Throw 100 hanging sliders, and you’ll get crushed. Throw one, and the odds are good that you’ll get away with it.

This remains one of the strangest concepts in baseball. The best pitches are merely probabilistically the best. The worst pitches are only bad in aggregate. Watch a game, and you’ll see plenty of “how’d-he-get-that” hits and “how’d-he-miss-that” whiffs. It’s hard to talk about, because we like to think in absolutes. Do the good thing, get the good result, and vice versa. In the long run, that’s true. If you threw only hanging sliders down the middle, your average opposition would put up an Aaron Judge-level statline, and good hitters would tear you to shreds. But that’s in the long run. On any given pitch, there’s no telling what can happen – even if it’s the worst pitch you could possibly throw.