JD Thompson is primed to be the cornerstone of head coach Tim Corbin’s rotation for the 2025 college baseball season. As the lone experienced starter for Vanderbilt, he’s tasked with leading a young Commodore pitching staff and setting the tone at the top of the rotation. Thompson turned in a strong sophomore season on West End, pitching to a 5-2 record with a 4.15 ERA, inflated by one rough outing against Coastal Carolina (8 runs allowed). Over 52 innings of work across 12 starts, he struck out 74 batters while maintaining a 1.25 WHIP. With another year of development, Thompson is poised to elevate these numbers further as Vanderbilt’s ace.
Thompson possesses many qualities coveted in an ace, with his ability to generate swings and misses ranking among the best in college baseball. Last season he boasted 12.8 K/9 and a 36.2 whiff %, both elite metrics for a starting pitcher, especially one of his age. Standing at 6’0 tall and 203 pounds, the athletic left-hander can continue to add strength and velocity as he gains more experience.
Mechanically, Thompson is a very polished pitcher. His sound delivery helps him pronate the ball extremely well, allowing him to generate unique arm-side movement on his fastball and changeup. While his pitches don’t generally generate a ton of spin, his high-arm slot adds another layer of deception that helps keep hitters off balance.
Currently ranked at No. 65 on mlb.com’s prospect ranking, Thompson has the tools to climb draft boards with a standout 2025 campaign. Let’s take a look at what makes Thompson’s repertoire so effective and what he needs to do to cement himself as a top arm in the SEC.
A special fastball
Thompson’s fastball is, simply put, filthy. While it clocks in at a modest 90-93 miles per hour, the pitch’s extraordinary underlying metrics make it devastatingly effective. Thompson’s delivery plays a crucial role in his success, with a unique combination of a low release point and high arm slot. This rare but effective pairing allows him to generate more effective break on his pitches.
His delivery, specifically that high arm angle, helps Thompson produce a well-above-average 18.1 inches of induced vertical break, leading to a movement that makes the ball appear to rise as it approaches the batter. The result is a fastball that boasts a 37.3% whiff rate and 32.5% chase rate, both extremely high metrics for a four-seam fastball. Additionally, the pitch exhibits 12.1 inches of arm-side horizontal break, adding yet another layer of movement and unpredictability.
However, stuff alone doesn’t make a fastball as dominant as Thompson’s is. His ability to locate it consistently in the upper half of the strike zone is equally critical — his command in that area maximizes the pitch’s effectiveness. His rare mistakes usually occur when he leaks the ball to the lower inside quadrant against right-handed hitters. As he continues to perfect his mechanics, Thompson’s ability to pinpoint his fastball could become a difference-maker for the Commodores’ fortunes this season, especially considering that the pitch will no longer be a novelty to the SEC as opponents grow more familiar with it.
Still, even when hitters know the pitch is coming, Thompson’s fastball remains virtually unhittable. In 2024, he threw the pitch a staggering 59.1% of the time, far out-pacing his next most-used (16% use of his curveball). Despite this heavy reliance — and the absence of other fastball variations like a two-seamer or cutter — Thompson’s heater continues to mow down hitters. Its ability to miss bats despite its predictability underscores just how special the pitch truly is.
A promising changeup
While Thompson has a dominant fastball, his secondary pitches leave a lot more to question. His changeup’s roughly average movement — 9.1 inches of vertical break and 11.7 of arm-side horizontal movement — isn’t overwhelming by any means, but is serviceable, especially when paired with his fastball. Perfect Game called Thompson’s 82-mile-per-hour changeup his most effective pitch coming out of high school, and its early results have been promising. In 2024 the pitch induced a ton of weak contact, with its xwOBAcon (Expected Weighted On Base on Contact) at an elite .255, albeit a small sample size of just 107 pitches. These early returns suggest Thompson’s changeup could develop into a reliable secondary offering.
However, Thompson threw his changeup just 13.1% of the time last season, mainly to right-handed hitters. The change was reasonably effective but seems to get its outs because of the deception created from the fastball, as hitters sit on the heater and struggle to adjust. If he can gain more confidence in the pitch, it will become a crucial weapon to help him keep hitters off balance. While Thompson’s fastball is the calling card of his repertoire, its dominance is unsustainable in isolation, and an improved and more frequently utilized changeup will take him to the next level of success.
A pair of breaking balls
Thompson rounds out his arsenal with a pair of breaking balls: a slider and a curveball. On the surface, these two pitches seem similar, but his slider stands out as the more encouraging of the two offerings. Thompson’s slider is a hybrid between a gyro and a sweeper, breaking about 7 inches horizontally and averaging 79 miles per hour on the radar gun. Like his fastball, Thompson’s slider spin rates are low, but he makes up for it with his deception — he generated a 34.6% chase rate on the pitch last season. Thompson loves using it as a putaway pitch to lefties, starting it on the plate before breaking it down and away, frequently in the dirt. But like his changeup, he used the pitch sparingly in 2024 — just 12.2% of the time — which makes it difficult to gauge its long-term potential. Still, with high whiff and chase rates, the pitch could be a weapon against left-handed hitters, especially if he increases its velocity to the low-to-mid 80s.
Thompson actually threw his curveball more than his slider or changeup in 2024, and while it spins a little bit more than his slider, the pitch has been far less effective. His curveball’s chase rate is just 18.2%, clearly indicating the slider is the southpaw’s superior putaway pitch. The curve loses about three miles per hour from the slider, which gives hitters more time to recognize the pitch and lay off of it. If Thompson could locate the curveball for strikes early in counts, it could help its effectiveness with two strikes, but as it stands it is more of a waste pitch than anything else.
The bottom line? Thompson’s fastball alone makes him an elite pitcher in the SEC, but his development as a complete pitcher will rely on his ability to refine his secondary offerings. As Vanderbilt’s ace, his consistency and polished mechanics should provide a solid foundation for success in 2025. If he can enhance his changeup and slider, while finding greater utility for his curveball, there’s no ceiling for how dominant Thompson can become.
With the SEC’s toughest lineups awaiting him as Vanderbilt’s new big game pitcher, Thompson will have to embrace the challenge to solidify himself as one of college baseball’s premier arms.
