Backroads and Ballfields: Texas Lands Jack Postma, a 6-Foot-5 Righty Who Lets Go Low
By Daniel Wilson ·
At the Prep Baseball All-American Game in Miami in September, Andy Sroka of Prep Baseball Report listed Jack Postma's release height at 4.8 feet with 7.2 feet of extension. Shooter Hunt, also of PBR, posted 4.9 and 7.3 in his own write-up that month. Two evaluators, close enough to believe. Postma is 6-foot-5. Pitchers that tall usually release the ball higher. By those numbers, this one gets down the mound and lets go of it closer to the dirt than his frame suggests he should.
Texas landed him. Sam Fariss of Hook 'Em Headlines reported on Oct. 7 that Postma, a 2028 right-hander from Barrington High School in Barrington, Ill., committed to Jim Schlossnagle's program, and that he has already thrown a 92.5 mph fastball. PBR's profile dates the commitment to Oct. 6. His own post on X, on the evening of Oct. 7, kept it short: "Committed" and "Hook em."
The 92.5 holds up. PBR's TrackMan readings list it as his max at the All-American Game, with the fastball sitting 90.5 to 92. Perfect Game's profile shows a 93 from one of its events on July 16, so the top end on the gun is at least that. The 78 mph curveball Fariss mentions also appears in PBR's data, from the Future Games on July 22.
How the Fastball Climbed
What I keep coming back to is the slope. PBR's event logs have Postma topping out at 81 mph at an ID event in April 2024. He was up to 89 at PBR's preseason underclass all-state event in March 2025, 91 at the same event in February 2026, 92.4 at the Future Games and 92.5 in Miami. Over the same stretch, his measured size went from 6-foot-3 and 186 pounds in March 2025 to 6-foot-5 and 208.6 in September. The line isn't perfectly straight. At PBR's summer events in 2025, he topped out between 83 and 86. Then he went from 84 at the Illinois State Games in August to 91 in February. A teenager can become a different pitcher over one winter, and Postma did.
A Breaking Ball Without a Name
The breaking ball is where the information gets interesting. PBR's data tags it as a slider at some events and a curveball at others, and at the All-American Game the two entries carry the same readings, 74.9 to 76.7 mph. Hunt wrote it up as "CB/SL" and called it sweepy. A PBR report in March measured an average of 13.6 inches of horizontal break on the slider version. I don't know yet what the finished pitch will be called. The changeup has a longer paper trail: 82 to 84 mph in Miami, and PBR evaluators were noting its fade back in his freshman year.
What His Spring Games Showed
Showcase numbers answer how hard. Games answer other questions, and his spring answered a few of them. PBR reported a complete-game no-hitter for Barrington in the MSL championship in May, a 5-1 win with two walks, six strikeouts and one unearned run. A later PBR note that month logged another complete game with nine strikeouts, no walks and 68 percent strikes. In an April start, on what PBR called an "upper-40s/low-50s day," he was still reaching 87 in the sixth inning.
None of that settles the command question for a pitcher his size, and PBR said so plainly in April, writing that it "will take time for a pitcher his size to fully harness his movement patterns." That is a fair note on a 16-year-old with this much arm and leg to organize.
The Rest of the Texas 2028 Class
Postma joins a Texas 2028 class that already had some weight to it. Fariss listed Theo Swafford, Chase Cotton, Tommy Driver, Parker Klug, Colton Small and Jake Welch. (Hook 'Em spelled his name Klung; Perfect Game's commitment list has Klug.) Perfect Game's Texas list also includes Trendyn Motley, an outfielder from Huntersville, N.C., listed at 6-foot-5, who isn't in the Hook 'Em rundown.
Swafford is the first name on Fariss's list. He is a left-handed-hitting shortstop from Ventura, Calif., who plays at Sierra Canyon and is listed at 5-foot-11 and 180 pounds. At Perfect Game's Junior National Showcase in June, he ran a 6.83 60-yard dash and threw 92 mph across the infield, and PG's report said he "projects to stick" at shortstop. He committed to Texas in September, per World Baseball Network. An athletic shortstop with that arm and a chance to stay in the middle of the field is my favorite thing to evaluate in amateur baseball, so he goes on the follow list too.
Fariss also made the point that belongs next to any commitment this early. Top baseball prospects often sign out of high school, so programs like Texas collect far more commitments than ever reach campus. Postma and Swafford are both 2028 graduates, which puts them in line for the 2028 draft before either could play a game in Austin. Neither has an 80Grade draft rank yet; our board is still built around 2027.
What Comes Next
What would move the evaluation? A spring where the breaking ball settles into one shape and lands for strikes, and a fastball that holds 90-plus deep into seven-inning starts rather than in short showcase looks. The release and the frame are already there. The next numbers worth waiting on come from Barrington in March.