How Batters Have Done Against Aroldis Chapman’s Fastballs

Aroldis Chapman closed on Monday, and he threw some pitches incredibly hard. Now, on its own, that’s nothing new. That’s kind of his whole deal. Aroldis Chapman threw baseballs hard. The crow perched in the tree behind me was earlier literally flying in the sky. The world is amazing. But then, Chapman’s pitches were unusually hard, at least. Even by his own insane standards. He was buzzing 105 miles per hour, and other pitchers just don’t do that. Chapman was throwing pitches the likes of which we’ve barely ever seen.

So some attention is warranted. In response to Chapman’s outing, Dave asked how hitters have done and behaved against A++ heat. What’s happened when Chapman has thrown around his own personal maximum? I’ve done research. It’s all spit out for you below.

Before moving on, I’d like to say this was made possible by Baseball Savant. Many things are! And you should get some visuals. Here’s the fastest pitch thrown in the young Statcast era:

It was wild, which docks it points, but speed is speed, and the speed is undeniable. And here’s how Chapman finished his save:

That’s the fastest pitch ever put in play against Chapman. And maybe that’s not a surprise, since that’s also just one of the fastest Chapman pitches on record. But to find the next-fastest pitch put in play, you have to drop by more than a mile per hour. That bat was doomed. If it was going to make contact, that bat was doomed. There was no alternative but to explode.

So to get to the numbers, I pulled up Chapman’s whole career, and looked at his fastballs. I grouped them by velocity, as recorded by the pitch-trackers, and here’s a sense of Chapman’s fastball-speed distribution since he arrived in 2010:

It’s crazy to see, even when you knew what it would look like. The speed of Chapman’s arm just doesn’t get old. As a major leaguer, he’s sat around 99. Sometimes he goes slumming, and sometimes his arm hurts, but other times he pushes 104. On occasion, he exceeds that. He exceeded that Monday. Given all the trade rumors flying around, the Yankees might call it good timing.

Now a table. As shown above, I put all of Chapman’s fastballs into nine groups. Here are results within those groups. You see the number of fastballs in each group, plus the zone rate, the swing rate, and the in-play rate. For the first two, the denominator is all fastballs within the group. For the in-play rate, that’s just out of the swings. I don’t know what you’re expecting, but, expect no longer!

Because of the sample sizes, trends present aren’t perfectly smooth. Yet there are a few things we can spot. Generally, as Chapman has thrown harder, he’s been slightly less likely to find the zone. Maybe not a shock. More surprising: Along with Chapman’s increasing velocity, opponent swing rates have gone up. Hitters haven’t just sat back and acted helpless. Perhaps this is because, with less time to react, hitters need to commit earlier, and they’re inclined to attack. Alternatively, Chapman — like many pitchers — throws harder with two strikes, and when there are two strikes, hitters get into swing mode. That has to be some kind of factor.

And, you have the last column. Once more, not a shock. As Chapman’s pitches have gotten harder, opponents have had a tougher time putting said pitches in play. When Chapman has thrown at least 103 miles per hour, opponents have swung 50 times. Half those times, the pitch has been fouled off. Another 18 times, the hitters have whiffed. Seven of those fastballs have been hit fair. Credit to Carlos Ruiz and Bryce Harper, who are responsible for the hits, one in 2010 and the other in 2015.

For simplicity, right here, I decided to just draw one line, at 100. And in this table, I’m also including league-average fastball rates, for 2016. Nothing wrong with providing a little context.

Even at his highest velocities, Chapman hasn’t been too wild. If anything, he’s encouraged swings. And that last column is the most dramatic one. On average, when hitters swing at a fastball, they hit it fair 40% of the time. That rate drops to 25% against Chapman’s B-level heaters. Against his A-level stuff, the rate dips further, to 18%. So, less than half of the league-average rate. It turns out there is a difference between 99 and 100, or 100 and 101. It feels like it shouldn’t matter at that point, but every split-second counts, and the freshest Aroldis Chapman really is untouchable. As untouchable as you can get, anyway. Hitters have almost no time to decide, which strips them of their ability.

There are your Aroldis Chapman results. At the highest velocity levels, he’s responsible for almost all the results in the game. One might take notice of Mauricio Cabrera, who’s already thrown 20 pitches at least 102. Half of those pitches have generated swings, and three have put a ball in play. In one sense, Aroldis Chapman finally has some company. In another sense, no, he probably doesn’t.