The Latter Years of Jacob deGrom

I have a hot baseball take. The most dominant performer I’ve seen in real life isn’t Shohei Ohtani, or Aaron Judge, or Barry Bonds. It’s Jacob deGrom, and specifically the form that deGrom showed starting in 2019. He mostly threw fastballs and sliders. He only attacked one side of the plate. It sounds like a bad approach, one that a thoughtful hitter could easily exploit. Yet it was absolutely, completely unhittable.

Why? First, deGrom’s fastball is a unicorn. His combination of release point, shape, velocity, and command means that batters are trying to hit flat and even seemingly rising pitches on the edges of the plate. By releasing so low and yet generating so much backspin, he’s defying expectations. By throwing it so hard, he’s giving batters less time to react. By spotting it on the edge of the plate, he’s giving them no good options even if they swing; it’s hard to do damage on pitches that avoid the center of the plate.

From 2020 to 2022, the velocity part of this equation kicked into overdrive. In each of those years, deGrom averaged 98.7 mph or faster with his fastball. But it turns out it still looks pretty good at 97:

It’s worth mentioning, too, that deGrom didn’t always work to one side of the plate. He came up with a balanced approach. But as he gained velocity and refined his arsenal, he moved everything to the most effective part of the plate for his slider: the glove-side edge. Here’s a chart of where he threw his fastballs in his final start with the Mets, in 2022:

And here’s this Sunday’s start:

Those are indisputably different patterns. And that 2022 start wasn’t even the most extreme he got. Here’s deGrom at the peak of his powers in 2021, a 15-start season that was worth 4.9 WAR thanks to a 1.08 ERA and 1.24 FIP:

So now deGrom is moving his fastball around more, and seemingly focusing high instead of glove side. Even with diminished velocity, our pitch models still like the fastball quite a lot, though of course one game isn’t enough to be sure. The shape is a bit more east-west than it was at his peak, though again, let’s give him a few more starts before we feel confident about that. Either way, I think it’s clear that deGrom’s fastball is still quite impressive even toned down somewhat.

Of course, it’s not as good as it was when he was throwing it 100, but deGrom has made changes to account for that. Over the past five years, he’s thrown a fastball or slider roughly 90% of the time despite having an excellent changeup and curveball. As the indispensable Lance Brozdowski pointed out, though, deGrom took both pitches out of mothballs over the weekend. In pie chart form, here’s 2020-2024:

And here’s 2025, one start in:

Yeah, it’s not a huge change. But think of it this way: He’s roughly doubled his combined usage of the curve and change, taking it all out of his fastball frequency. And, naturally, there are knock-on effects. The more changeups he throws, the more profitable arm-side fastballs become, which helps explain some of his changed location. Changeups like this are lethal when hitters aren’t sure where to look:

His curveball is a fun wrinkle. It was my favorite of his pitches when he first came up, a two-plane bender he controlled like it was attached to a string. He used it to steal strikes, but also to add further mystery to the classic “is it a fastball or a slider?” game. Add a curveball into the mix, and now his pitch could look like a slider but get to the plate much more slowly. At his peak, deGrom didn’t need that extra wrinkle. There was no point in a show-me curveball when he could show his top two pitches every time and still dominate. But bringing it back as a weapon will curl hitters up into knots if it’s effectively used as a change of pace.

Let’s look at those pitch clusters one more time. Here’s the fastball-and-slider version of deGrom from a typical 2021 start:

You get the idea; the blend of those two pitches just overwhelmed hitters. Fast or faster, bendy or featuring mind-bending rise, it didn’t really matter. But while that’s one way to overpower hitters, it isn’t the only way. Here’s deGrom from Sunday, all together now:

I don’t want to make too much of deGrom’s mixing things up. I certainly don’t want to pretend he’s pitching to contact; his 20.5% swinging strike rate on Sunday says otherwise. His six strikeouts in five innings didn’t come by accident. His slider is still going to give opposing hitters nightmares:

But it’s hard to argue he’s the same guy. Look at those pitch maps. They’re very clearly evidence of different intent. I’m not saying deGrom is going to stick with how he pitched. There were a few too many sliders left over the middle of the plate for comfort, and his fastball sometimes leaked high. Two walks is uncharacteristic for someone with his command, and in watching the start, I saw him leave a fastball wide and then get annoyed more than a few times.

After watching this start, I’m buying the idea that deGrom is purposefully pitching in a lower gear to preserve his health. He’s not suddenly a soft tosser out there or anything – only 11 pitchers are averaging more velocity on their four-seam fastballs this year. He’s still throwing that nasty slider a lot, and still throwing it hard; sure, 89.5 mph isn’t quite his peak velocity on the pitch (92.6 in 2022, how ridiculous), but you guessed it, it’s still one of the fastest sliders in baseball. This is about as much as we’ll see him take his foot off the gas pedal.

But the good news, for Rangers fans: Gas-off deGrom might still be the best pitcher in baseball. He looked like he was still working himself into game shape in his outing, barking at himself or looking down at his foot positioning after the odd loose pitch. He purposefully built up slowly this spring, and might still be doing so now. Maybe the rest of his buildup will come in the form of better command instead of more velocity. But one thing feels clear to me: This version of deGrom might not throw as hard, but it might not matter. By breaking out two rarely-used pitches in an effort to sustain both his health and his production, deGrom seems to have found yet another level of dominance.

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