Post-Back Injury Devin Williams is a Different Pitcher, in Two Different Ways

With an injury like the one that hampered Devin Williams over the offseason and stole the first half of the regular season from him, it's worth taking a close look at the stuff upon his return. There was no surgical intervention on the stress fractures in Williams's upper back; he just had to wait and build up slowly after giving the injuries time to heal. Though they might be becoming more common as pitchers try to maximize torque and extension through their release, injuries like that one are still quite rare, and it was hard to guess exactly how Williams would look on the other side of it.

There have been material, noticeable changes. Some of them appear to be for the better. Some could be for the worse, in that they might indicate that he's compensating for or sheltering himself against the extreme toll his former style was exacting--or they could reflect a newfound freedom of movement, after he was limited by the nagging back issue even late last season. For one thing, some of the trademark extension that made everything in his arsenal play up in dazzling fashion over previous years is gone. Here's an overhead view of where he was releasing the ball in 2023, where the (0, 0) mark is the center of the rubber, progress to the right is toward home plate, and a lower number on the apparent vertical axis means a release farther toward third base.

Now, here's the same chart for this season.

Williams has lost about half a foot of release extension this season, and a bit more than that on the fastball. As you can also see, his release point on the fastball is farther toward third, and more in line with that of his famous screwball. Often, a shift of six inches or so in lateral release point (with or without a change in release extension) signals a shift in where a pitcher is setting up on the rubber, so I wanted to check whether Williams has slide over toward third in his initial position this year. Here's a fastball on which he got a swinging strike last September:

And here's the one on which he struck out Shohei Ohtani last week.

There's no shift in starting position here. Rather, Williams has gotten more crossfire action going in his delivery. If you're struggling to see this, look at where his left foot lands on each pitch. Last season, it was more or less in line with the middle of the plate. This year, it's all the way to the outside corner.

From here comes at least a portion of the increase in velocity Williams has demonstrated this year. He's throwing harder, and part of that is creating a more closed front side against which to drive. He's not exploding down the mound with the same flying athleticism, but he's making up for that with a change in his release angle and arm action. His fastball movement hasn't changed, but it's gained speed and even a little bit of carry, in the form of a flatter vertical approach angle. That comes from the change in the way he moves down the mound.

Is it something Williams is doing on purpose, and that he was unable to do for much of last season, as he dealt with undiagnosed back pain? There's no evidence to tell us that he was materially hampered in the second half of 2023. He wasn't doing any version of this crossfiring in 2022. Here's a video from earlier last year, just before the Fourth of July, in which he is equally direct to the plate, but perhaps a bit more fluid through release.

However, the data might be telling us that Williams hasn't actually lost extension at all; he's just changed his angle, to increase his deception. In other words, he's covering the same ground with his stride and launch through release, but at a slight angle toward the right-handed batter's box, to further flummox opposing batters.

This, too, could be a matter of injury prevention, but in a different way. It's only been seven appearances, but Williams is throwing his fastball 61% of the time, and breaking out the airbender less often than is his wont. That might be to protect his body from the various ravages that pitch inflicts on it; the fastball is less dangerous to his arm. He hasn't used the cutter he worked on assiduously as recently as spring training, but maybe that's just because he hasn't needed it yet. We might be seeing a new version of Williams, with a delivery wired for slightly greater deception and the goal being to rely more on the fastball, rather than the airbender.

Free agency looms after 2025, which figures to inform both Williams's approach to the balance of this season and the Brewers' usage of him. At the same time, both parties badly want for Williams to be in position to secure wins for his team every time they're there to be had. A slight alignment change and an attendant tweak in pitch mix look like the first pair of ideas they've come up with to make that a reality. How long they can last, and whether they'll be the only ones, is anyone's guess.