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Red Sox take batting practice to a futuristic level with ‘robot pitcher’ replica of the opponent

The Trajekt Arc is a video projection system that works in tandem with a programmable pitching machine to deliver pitches that replicate those of real major leaguers.Trajekt Sports

If Red Sox hitters want to prepare to face Gerrit Cole, what better way to do so than by facing Gerrit Cole?

In a batting cage at Fenway South in Fort Myers, Fla., Red Sox hitters now have the option to do just that whenever they’d like. With a few clicks, players can summon an avatar of the Yankees ace on a projection screen and stand in against actual high-90s fastballs at the top of the zone, biting sliders, and anvil curveballs that mimic Cole’s release point, velocity, spin, spin axis, and movement.

“It’s crazy,” Red Sox newcomer Justin Turner said. “Things have definitely come a long way.”


In the middle of last season, the Red Sox became one of a growing number of teams using the Trajekt Arc, installing it in the home batting cage at Fenway. The video projection system works in tandem with a programmable three-wheeled pitching machine to fire pitches that replicate the arsenals of real major leaguers more closely than any known training tool in baseball history. This spring, the team added another Arc at Fenway South.

So what is it?

“A pitch-replication robot that can replicate any trajectory,” said Trajekt co-founder Joshua Pope. “If you want to re-create a pitch, we can re-create it for you.”

Red Sox players can select from a list of available pitchers, whether it be a teammate like Tanner Houck or an opponent like Cole. When they do, a projection of that pitcher on a mound appears on a three-paneled screen roughly 55 feet from home plate.

The Trajekt screen rolls on a set of metal tracks so that its center lands at the pitcher’s horizontal release point, up to 3½ feet from the middle of the rubber. The middle panel then moves up or down, with a squared circle in the middle of the screen — an opening through which a pitching machine fires pitches — arriving at the pitcher’s vertical release point 4-7 feet off the ground.


Once the desired selection of pitches is identified, the pitching machine’s wheels move to precisely adjust the spin and speed of the ball. There is also a patented ball-orientation controller that positions the seams to precisely configure the movement of a ball — critical, for instance, for firing a two-seam as opposed to four-seam fastball.

From the stretch or windup position, the projected pitcher moves through his delivery. When the hand arrives at the release window, a pitch with the movement profile of the specific big leaguer is fired at the plate.

Players can choose whether the machine fires pitches in the zone, out of the zone, or both. They can request only one pitch type — say, a succession of Devin Williams changeups — or a random assortment of a pitcher’s mix.

“You’re actually creating shapes and release points and angles, do things that you normally can’t do,” Red Sox hitting coach Pete Fatse said. “It’s really special.”

For most of two weeks after getting hit in the face by a pitch March 6, Turner couldn’t hit outdoors or face live pitching. Instead, he kept his eyes trained on the devastating repertoires of opposing pitchers by using the Trajekt system — confident that his safety wouldn’t be threatened by a stray pitch.

With the Dodgers, Turner had used virtual-reality systems that approximated the flight of specific pitchers’ repertoires. But he didn’t love the system, feeling that it failed to replicate the ball coming out of a pitcher’s hand and the spin/movement profiles of actual pitches.


While Turner said that it’s hard to see the ball out of the pitcher’s projected hand with Trajekt, the fact that it captures a release point while also firing actual (instead of virtual) baseballs with the spin and movement of real pitchers makes it a considerable step forward as a training tool — and light-years removed from the training tools that existed when he entered pro ball in 2006.

“It’s good to have the visual and see a pitcher’s motion and windup and try to understand the timing that you’re going to have versus different guys,” said Turner. “I think that aspect of it is great for your eyes.”

Nearly half of MLB teams now use the Trajekt Arc. Some, like the Red Sox and Twins, have more than one. According to an industry source, the machines are leased to teams for a five-figure monthly fee.

Whereas the system comes with generic pitcher projections, the Sox have adjusted theirs to project the image of specific pitchers. They’ve also paired the Trajekt system in their cage with HitTrax, a system that tracks the exit velocity, launch angle, and launch direction of balls as they’re hit and maps them onto a virtual image of Fenway Park.

Minor leaguer Ryan Fitzgerald raved about the opportunity to prepare by replicating game conditions and described such equipment as the necessary counterbalance to the data-driven pitch development that has made hitting more difficult than at any point in baseball history.


“If pitching hadn’t gotten as good as it has, we wouldn’t have to train like this,” said Fitzgerald. “But guys are throwing 98 every day with sliders that have unreal spin, verticals and horizontals.

“When you’ve got machines like Trajekt that can match the spin access, spin rate, and then obviously arm slot and all that, that’s really the only way we can compete with them.”

Trajekt creates more challenging practice conditions than had traditionally been available. Rather than smashing batting-practice pitches and driving them to distant regions of the ballpark, players must confront humbling arsenals.

For that reason, some prefer to use the Trajekt system simply to train their eyes by tracking pitches. But over time, many initially reluctant hitters find the temptation to battle against big league-caliber pitching irresistible.

“I would rather be successful 2-3 times out of 10 than be successful every time in practice,” said Fitzgerald. “That’s what I like about it. It’s realistic.”

MLB currently permits the use of Trajekt before and after games — but not during them. Fatse surmised that the machines could be seen as creating an unfair in-game advantage given that a visiting team wouldn’t have one.

The system also has other applications. It can be used for pitch design (for instance, getting a read on what a pitch with a specific velocity and spin might look like if the seams were reoriented), catcher development, and umpire training. It can spare coaches’ arms; there’s a setting on the Sox’ machine that has Fatse throwing batting practice at 75 m.p.h.


The system also permits pitchers a through-the-looking-glass glimpse of themselves from a batter’s perspective to achieve greater self-understanding of their arsenals.

“Everyone at one point in their life has always said, ‘Oh, I wish I could face myself,’ ” said Houck. “And now you actually can, so it’s kind of time to put your money where your mouth is. It’s truly revolutionizing the game.”

Alex Speier can be reached at Follow him @alexspeier.