Jordan Hicks Raised His Arm Slot 10 Degrees—Then Everything Changed

Jordan Hicks built his reputation with velocity. As a rookie, he touched 105 mph. In 2023, during his last full season as a dominant reliever, his fastballs averaged 100.1 mph.

Then came a two-year detour. San Francisco moved him into the rotation in 2024, his velocity backed up, and he finished 2025 with a 6.95 ERA. The White Sox acquired him the following February and returned him to the bullpen, but the old version did not immediately return.

Hicks posted a 5.60 ERA with a 17.2% strikeout rate over his first 20 appearances. A right lat strain then cost him a month.

When he came back on June 21, the velocity had returned—but the more important change was where his arm delivered it.

Weapon Check

Hicks described the adjustment as raising his arm slot “a little bit.” The measured difference was much larger.

In his first appearance of the season, Hicks released his fastball from a 29-degree arm angle. In his first outing off the injured list, that angle was 39 degrees, according to MLB’s mechanical analysis. His 2023 arm angle—the version he wanted to recover—was 40 degrees.

That higher release changed the shape of both fastballs.

Hicks’ four-seamer averaged 9.1 inches of induced vertical break in March and April. By August, it had climbed to 14.5 inches. His sinker added roughly four inches of vertical movement, reaching 11 inches.

Neither pitch suddenly became an elite rising fastball. That was not the point. At nearly 100 mph, a few extra inches of carry can change where a hitter expects the ball to meet the barrel.

The fastball was not only harder. It stayed above the expected bat path longer.

Hicks also began trusting the four-seamer more. Since returning, he has thrown it 27.3% of the time—the highest usage rate of his career. He told the Chicago Sun-Times that the old video helped him identify the delivery he wanted, while playing catch with the four-seamer helped him rediscover its feel.

The pitch became more than a velocity reading. It became a weapon again.

Seam Study

The results reveal how much the new geometry changed the at-bat.

Through his first 18 appearances after returning, Hicks recorded a 1.17 ERA and struck out 38.7% of opposing hitters across 16⅓ innings. His combined four-seam and sinker velocity climbed from 98.2 mph in April to 99.9 mph after the injured-list stint.

Before the injury, hitters batted .304 and slugged .413 against his fastballs. Afterward, those marks fell to .205 and .273. The whiff rate more than doubled, moving from 8.4% to 19.6%.

His four-seamer has been especially difficult to square up. In the current Baseball Savant season line, opponents are batting .045 and slugging .091 against it. The pitch owns a 27.1% whiff rate and a plus-three run value across 86 offerings.

Hicks is also getting the pitch into better locations. His fastball zone rate rose from 51.3% in the first month of the season to 58.2% in July. More carry gave the four-seamer a better shape; more strikes allowed that shape to matter.

There is one detail worth watching: Hicks’ full-season walk rate remains 14.5%. Reliever samples move quickly, health is still part of the equation, and hitters will adjust to the new look.

Still, the process supports the performance. The release changed. The fastballs gained vertical movement. The velocity returned. The strikes and whiffs followed.

That sequence matters for Hicks and for a White Sox bullpen that posted a 3.00 ERA over the same seven-week stretch, fifth best in MLB.

Hicks did not invent a new pitch. He restored the delivery that allowed his best pitch to behave like itself again.

Disclosure: All pitch data used in this article was sourced from Baseball Savant. Mechanical details and pre-/post-injury splits were reported by MLB.com. Hicks’ comments about reviewing old video and playing catch with his four-seamer were reported by the Chicago Sun-Times.