Jackson Chourio is Almost Back to Full Strength, and Turning Yet Another Developmental Corner

Even if you have a dazzling combination of speed and power and can often get the bat on the ball even when fooled, eventually, you have to learn not to let big-league pitchers choose what you're going to swing at. Jackson Chourio did a marvelous job of handling the difficult transition to the majors at age 20 in 2024, batting .275/.327/.464. This year, however, he came out of the gates swinging at everything he saw, which led to an early slump. He entered July with just a .286 on-base percentage, despite hitting for average and power at better rates than the league.

Chourio is an aggressive hitter, and he should remain so for years. He hits the ball too hard and has too much potential to break games open with his all-fields power and running ability to sit and wait for the perfect pitch at all times. However, there were clearly times during the early portion of the season when he was too much in swing mode, and wasn't getting even a manageable pitch to hit in each at-bat.

As you can see, though, that's changed since the start of July. He didn't go on a walks binge during that month, but by being slightly more patient, he found more offerings he could crush, and batted .367/.408/.600. That's why it was such a blow when he went down with a hamstring strain just before the trade deadline; his loss was arguably the biggest factor in the Brewers' gentle regression from a historicly torrid run to a solid-but-unspectacular second half of August.

Since coming back, Chourio has seen some ups and downs. He exploded back onto the scene with two games in Toronto in which he collected six hits, but then had a few hitless games as he battled to get back into his rhythm at the plate. Nonetheless, in a total of 35 plate appearances since his return, he's batting .267/.343/.533. Interestingly, he's also walked three times in that short span. He's taken seven free passes in 83 trips to the plate since the All-Star break, after accepting just 18 in 424 times up before it.

When a hitter like Chourio starts swinging this infrequently, you have to assume that part of it is a lack of real comfort with his swing, which is a bad thing. On the other hand, sometimes that very discomfort forces a hitter to be more disciplined or just to work deeper counts, which can be a good thing. Chourio's bat speed is down in September, but not to any dangerous lows; he's just not getting off his 'A' swing quite as frequently lately. That's as much about timing as anything else; he's not the only Brewers hitter who is still getting some rust brushed off.

Unlike Joey Ortiz, though, Chourio's attack angle and direction this month aren't out of whack. Nor has his contact point migrated in any particularly telling way. He's getting to the ball where he needs to, which is why he's found plenty of success, even while getting back into the saddle. To understand why he's so adaptable, let's talk a little bit about adaptability in a swing; getting on plane; and how hitters go about ensuring that they're on time.

Here are six hitters' swing animations, from Baseball Savant, at the moment when their swing ceases to be about bringing the bat down into the back half of the hitting zone and starts working up through the ball. Every viable swing starts with a negative attack angle, and by the time you're really in the hitting zone, your goal is to have a healthily positive one. These animations illustrate the different ways hitters do that, and open a discussion of the pros and cons of each. 

I've essentially highlighted this year's version of Chourio, for ease of viewing. The others are, clockwise from the top left: Andrew Vaughn, Brice Turang, last year's Chourio, last year's Sal Frelick, and last year's Willy Adames. Vaughn, Turang, and the past version of Chourio are all en route to roughly the same average attack angle (7-8°) as this year's Chourio, but look at the differences in their body positions at this moment when the swing reaches its turning point.

Vaughn and Turang maintain a backward lean as they head toward contact. Their front shoulder is driving the rotation of their upper body and generating much of their bat speed, which means that it needs to be rotating backward already by the time the barrel gets to the ball. Vaughn's flatter swing will try to lash out and catch the ball with a late extension of the arms, with his lower half locking out so that he can make full use of the force of his front foot driving into the ground. Turang extends his arms much more, sooner; his swing is steeper and he needs to create more space to get through the ball on schedule.

Chourio doesn't swing like either. Although the comparison sounds wildly irresponsible, his swing really is something more reminiscent of righty batters like Willie Mays, Roberto Clemente and Henry Aaron. He gets into his legs more, which lets him adjust more things throughout the swing based on the incredibly rapid processing his hands and eyes can do as they spot spin, speed and location cues. Speaking of those hands, much more of his bat speed comes from them, so his front shoulder stays in longer. Thence comes all the power he can sometimes generate to right and right-center field. The key difference, relative to last year, is that he's not extending his arms quite as early or turning that shoulder out quite as soon—but he's still swinging faster, because he's gotten more accustomed to getting his 'A' swing off against big-league pitchers.

The 2024 versions of Adames and Frelick give us interesting examples of hitters trying to create a whole different attack angle than Chourio's. Adames depends on getting to the ball with the bat working steeply uphill, to maximize the likelihood of a hard-hit fly ball. As a result, you see a steeper barrel tilt, a more pronounced lean-back in his upper body, and his hands much deeper when he turns from swinging down to swinging up and through. A version of Chourio trying to swing like this would have to look very, very different. Frelick, though, is a low attack-angle hitter—or at least, he was last year. His swing is built to keep his weight back a little more than Chourio does, because a lefty has to be able to deal with pitches inside on them more than a righty does, but you can see the way his hands work being a bit more similar to Chourio. 

All of this means that Chourio contacts the ball fairly deep in the hitting zone, relative to his own body—because his body comes forward more than do those of most modern hitters. For such a player, a small loss of bat speed makes a big difference in how comfortable the swing feels and whether he can get the barrel there. That's probably why we're seeing Chourio swing less often lately; he's not feeling able to get up to speed yet. He's making good decisions under those constraints, though, and you can still see him doing some impressive things when he does get his timing right and fire the best version of his swing.

For the Brewers to get to the World Series, Chourio will have to be at his best in October. The early returns this September suggest that that's very possible, even though he's only spent a small portion of the season to date playing at that level. With his combination of tools and feel for hitting, if he can lock in his approach as he gets back to full strength, this could be the moment when he goes from a great developmental story and a star among baseball fans to a true household name.