Jackson Chourio’s Big Step Forward

Jackson Chourio got a late start to his season. A fractured metacarpal in his left hand, suffered during the run-up to the World Baseball Classic but not definitively diagnosed until three weeks later, knocked him onto the injured list just hours before the Brewers’ Opening Day game, and he didn’t make his season debut until May 4. Since then, the 22-year-old outfielder has not only been one of the majors’ top hitters, he’s shown notable improvements in a few key areas while helping to propel the Brewers into first place in the NL Central. He’s becoming the star the Brewers hoped he would when they signed him to an eight-year, $82 million extension in December 2023, before he’d even debuted in the majors.

On Wednesday night against the Guardians, Chourio hit his 10th home run of the season, turning a high cutter from Gavin Williams into a two-run opposite-field shot that helped the Brewers to a 9-4 win:

The home run was Chourio’s sixth in a seven-game span. He hit two against the Athletics in Las Vegas on June 9 and 10, part of a surreal flurry that produced 22 homers between the two teams during their three-game series. The Brewers lost those two games, as well as the June 13 contest against the Phillies in which Chourio hit two home runs and drove in four of Milwaukee’s eight runs in a 9-8 loss, but he hit a leadoff homer off Cristopher Sánchez the next night in a 4-0 victory, just the second homer the lefty allowed over his previous 61 innings:

In 38 games since being activated on May 4, Chourio has hit .307/.360/.558. Among players in either league with at least 150 plate appearances since that date, his 153 wRC+ ranks 11th:

What’s more, the Brewers were 18-15 and in fourth place in the NL Central, 3 1/2 games out of first before activating Chourio. Since then, they’re a major league-best 27-12 (.692), and have built a 5 1/2-game division lead over the Cardinals. Chourio isn’t even the hottest Brewer over that time frame; that honor belongs to Jacob Misiorowski, who has an 0.18 ERA in 49 innings during that span (his 0.17 ERA over his last eight starts and 54.1 innings is the lowest of any pitcher since earned runs became an official stat in 1913). On the offensive side, both Jake Bauers (.296/.424/.583, 181 wRC+) and Andrew Vaughn (.351/.442/.536, 175 wRC+) have been even hotter than Chourio, albeit in smaller slices of playing time (132 plate appearances for the former and 113 for the latter, compared to Chourio’s 178). Vaughn, who fractured the hamate bone in his left hand during his first plate appearance of the season, underwent surgery and was activated on the same day as Chourio. He and Bauers have shared first base duties since then, with the latter also spotting in left field on occasions when Chourio shifts over to center.

Chourio was hit on the hand by a Clayton Beeter fastball in Venezuela’s exhibition game against the Nationals on March 4. Initial X-rays were negative, and he was diagnosed with a contusion, but played center field for the tournament winners during Venezuela’s final two pool games and three knockout round games. Upon returning to the Brewers and undergoing a CT scan, he continued to play regularly until he felt pain during a checked swing during a March 24 exhibition game. At that point, the team sent him for an MRI, which revealed a small hairline fracture of his third metacarpal, and placed him on the injured list retroactive to March 25.

Publicly, the Brewers offered a two-to-four-week timeline for Chourio’s return, but his hand healed more slowly than expected, so he didn’t begin a rehab assignment until April 29, about five weeks after landing on the IL. He played just three games at Triple-A Nashville, giving the Brewers a scare when he fouled a ball off his left foot on May 2, forcing an early exit and a set of X-rays, which thankfully proved negative.

In Chourio’s absence, the Brewers used six different left fielders, with Brandon Lockridge, Greg Jones, and Blake Perkins each getting multiple looks. Though Lockridge put up a .377 on-base percentage in 77 plate appearances in that capacity, the group combined to hit .222/.305/.248 (58 wRC+) in 133 plate appearances over that span. Filling that hole in the lineup with one of the majors’ hottest hitters has provided quite an upgrade.

That production is also a big step up for Chourio, who batted .275/.327/.464 (118 wRC+) as a 20-year-old rookie in 2024 and a very similar .270/.308/.463 (111 wRC+) last year. He hit 21 homers in each of those seasons, with 22 steals in 2024 and 21 last year, making him the youngest player to go 20-20 twice. As those low on-base percentages suggest, those seasons weren’t without flaws. His walk rate eroded from 6.8% to 5.1% from 2024 to ’25, with last year’s 36.8% chase rate placing him in the eighth percentile among qualifiers. This year, he’s trimmed that chase rate to 32.6%, placing him in the 32nd percentile.

The biggest differences between Chourio’s previous seasons and his current one start with a faster swing. He’s increased his average bat speed, from 73.2 mph as a rookie to 73.9 mph last year to 74.8 mph this year; that’s a jump from the 70th percentile in 2024 to the 82nd percentile this year — or it would be, if he had enough swings to qualify. With that, his fast swing rate has improved from 34% to 40% to 52.1% over those three seasons. He’s also adjusted his attack angle, from an average of seven degrees in 2024 and ’25 to nine degrees this year, helping him elevate the ball with a bit more consistency. Indeed, Chourio’s contact numbers show the effect of his harder swings and greater loft:

Chourio’s average exit velocity has increased by almost three miles per hour, jumping from the 39th percentile last year (but the 60th in 2024, with very little actual change between the two seasons) to the 89th percentile this year, and while he got a late start to his season, the numbers above are well past the point of stabilization. His velocity gain is the second-largest among players with at least 300 plate appearances last year and 150 this year:

Chourio is the youngest player on that list, which is a young one in general, with just two players past their age-28 seasons. That shouldn’t be too surprising given that average exit velocities tend to peak in the mid-20s. Based on the June 30 age convention used on this site and elsewhere, the average age of the group above is 25.9 years.

Similarly, Chourio has the sixth-largest increase in barrel rate using those same cutoffs:

Again, Chourio is the youngest in the group, which isn’t much older than the previous one (average age 26.7 years).

One area where Chourio has particularly improved — or rather, rebounded — is in how he’s handling four-seam fastballs:

Statcast’s new swing timing metrics tell us that even with his improved bat speed last season, Chourio was late in swinging at four-seamers more often than in his rookie season. He’s been on time more often this season (71% vs 68%), and he’s also gotten under fewer four-seamers as well. His whiff rate against the pitch is higher, and while he’s mis-hit a similar share of them (about 7.5% of all of his batted balls in both 2025 and ’26), two of the nine four-seamers he’s gotten under this year have turned into opposite field homers, a 353-footer on June 4 off the Giants’ Adrian Houser and a 354-footer on June 9 in Las Vegas off the A’s J.T. Ginn:

Those may have been cheapies in terms of their distance, but they do point to Chourio’s success in hitting to the opposite field, something he’s done well since arriving in the majors:

Both Chourio’s actual and expected slugging percentages while going oppo rank among the majors’ top 20 this season, while his average exit velocity on those is fifth. He’s been so productive in that area because to date he’s hit just one opposite-field grounder (0.8% of his batted balls), down from a 6.4% rate last year; hit it in the air, and it might get out, especially when you hit it that hard. This year’s oppo rate matches his pull rate; meanwhile, his pulled air rate is just 9.9%, down a whole five percentage points from last year, and ranking in just the seventh percentile.

I don’t know how sustainable all of that is; I expect we’ll see regression towards his career marks, including a 6.1% oppo groundball rate and a 13.7% pulled air rate, but if he can maintain an exit velocity in his current neighborhood, he’ll hit his share of homers in that direction as well. The bigger takeaway is that Chourio has taken a substantial step forward, playing at a star level without having to change who he is or fit into a mold by conforming to the usual pulled-in-the-air model for offensive success. He’s still just 22, and it’s exciting to imagine where his development is going to take him.