Trajekt gaining popularity in MLB, putting pitchers on notice

Explore how Trajekt, a groundbreaking pitching machine, is transforming baseball training with new advantages, challenges, and ethical questions.

Hi, everyone!

Today, I have something pretty cool to share with you all.

First, a shout-out to my Uncle Robby. A couple of weekends ago, at my cousin’s wedding (shout-out to T.J. and Bri!), Robby was raving about a pitching machine called Trajekt. You’d think that as a baseball nerd, I’d already be familiar with it, but with two kids under four, it turns out I completely missed this latest innovation in baseball tech.

Naturally, I dove into some research, found it fascinating, pitched an article idea to my editor at Yardbarker, and wrote the column.

While working on it, I remembered my friend Justin, who has a background in biomechanics. A few months back, he and I were talking about Tred Athletics, a Charlotte-based company that’s transforming pitcher training and development. I decided to ask Justin a few questions, planning to incorporate his insights into my column—but his answers were so good that I thought they deserved a standalone feature.

So today, you’re in for a 3-for-1 deal!

“Three?” you ask. Yes! Last night, Matt, Ethan, and I recorded a podcast episode. Matt recently got engaged, so you’ll want to check that one out!

Then, you can read my Yardbarker column on Trajekt, which will be the perfect lead-in for my mini-interview with Justin below.

Thanks again to Uncle Robby and Justin for their insights. I hope you enjoy it as much as I have!

Colin, your cool writer friend who watched Penn State’s last win against Ohio State in person with Justin 😎 (yes, we know it was back in 2016): From a biomechanics perspective, what kind of advantage does Trajekt give hitters when they can practice against an exact replica of a pitcher’s delivery?

Justin Wager, baseball enthusiast with a PhD in Kinesiology from Penn State’s Biomechanics Lab: When we talk about the “biomechanics” of a swing, we’re looking at things like joint positions, velocities, and ground contact forces. Trajekt offers a lot of benefits, but I don’t think it’s ideal for building baseline swing mechanics. That’s usually done in the cage with simple pitches or through specific drills. Trajekt, however, can help ensure that established mechanics hold up against game-like pitches or certain types and locations of pitches. For instance, if a hitter struggles with breaking balls down and away or with pitches from a particular arm slot, Trajekt allows them to work on maintaining their mechanics against those pitches. It could also help hitters refine swing adjustments for specific pitch types, but I think it’s unlikely that players would have entirely different swings for different pitchers. More realistically, they might fine-tune their swing plane for certain matchups—say, a flatter swing for one pitcher and a more upward plane for another.

Colin: Do you think Trajekt could influence how pitchers approach their mechanics or pitch selection to stay unpredictable?

Justin: If Trajekt proves effective for hitters, elite pitchers will have to adapt. Variation will be key, with pitchers possibly developing alternate versions of their signature pitches or exploring new grips and arm slots to stay unpredictable. While we already see some of this in baseball, it could become even more common if hitters get better at reading familiar pitches. Pitchers might also experiment with arm slots, pitch shapes, and adding entirely new pitches to their repertoire. We could see year-to-year tweaks, where pitchers adjust a pitch in the off-season so hitters can’t rely on practicing against the exact same delivery. In the postseason, a new or slightly altered pitch could be enough to keep hitters guessing.

Colin: Could Trajekt expose pitchers to new types of strain or injury risks if they’re constantly adjusting to counteract this kind of preparation?

Justin: Absolutely. One clear risk is with arm slot adjustments. For example, changing arm slot can increase elbow varus torque (EVT)—a rotational force that raises the risk of UCL injuries if it becomes too high. The body can adapt to new loads, but only if these changes are gradual; sudden increases in load don’t allow time for the body to adjust, increasing injury risk. Changes in other mechanics, whether in the upper or lower body, can introduce new stresses that could lead to injuries if the tissues become overloaded.

(Hospital for Special Surgery and Motus published a study in 2017 showing that changes in arm slot and rotation can affect EVT: link to study)

Colin: What limitations might a machine like Trajekt have in truly replicating a pitcher’s movement and feel? Are there aspects of a pitcher’s mechanics or psychology that a machine just can’t capture?

Justin: Variation in pitches might be one limitation. Every pitch, even from the same pitcher, naturally varies a bit—even if the pitcher isn’t trying to change it. For instance, Blake Treinen’s sweeper can range from 12 to about 20 inches of horizontal break. Can Trajekt capture that natural range, or does it just replicate a single version? Can it mimic different styles, like a pitcher’s quick pitch or a hitch in their delivery? Another consideration is height and arm length. Does Trajekt account for tall pitchers by moving closer to the plate, as a tall pitcher might release the ball from a different position than a shorter one?

Colin: Do you see any ethical concerns around how biomechanics technology like Trajekt is used in baseball?

Justin: At the MLB level, I don’t see major ethical concerns—every team will have access to Trajekt, though some might be better at using it. But at the high school level, there could be issues with access. Some well-funded programs or wealthier families might afford Trajekt, giving their players an advantage, while underfunded schools might not. This disparity could impact player readiness for college-level pitching. Below the high school level, Trajekt is less relevant, as there aren’t distinct pitch types to prepare for. But it’s an interesting question—would love to hear your thoughts on this, too!