WATCH: AI Takes the Mound — Mariners train against virtual big-leaguers

At the Mariners Spring Training Complex in Peoria, a fastball zipped into the batting cage at 96 mph, thrown by a Kansas City Royals pitcher who isn’t even in the building.

“This is the guy we’re going to see today,” Ed Paparella, the Mariners’ minor league hitting coordinator, said. “We’ve got his video here. His video is out of the windup.”

Welcome to big league batting practice in the age of AI.

The Seattle Mariners are among roughly two-thirds of major league clubs using the Trajekt Arc, a pitching machine that pairs a life-size video projection of a pitcher with a ball launcher capable of replicating his velocity, spin rate, and movement with precision.

“Pretty much what it does is it creates every single pitch that’s ever been thrown in the big leagues,” Paparella said. “Our guys use it every single day.”

The machine has become essential as pitching continues to dominate the sport.

“Pitching took a big leap ahead of hitting,” Paparella said. “I think this kind of gives us a fighting chance.”

How the technology was born

Canadian engineer Joshua Pope came up with the technology. He first conceived of it as a teenager, arguing with friends about whether they could hit a big league pitcher. He realized Major League Baseball was already tracking every pitch.

“You could see how far a home run was hit, you could see the trajectory of every pitch,” Pope told “The Masters of Engineering Podcast.” “Obviously, there’s a lot of data being collected in baseball.”

Pope set out to turn that data into a training tool. The Trajekt Arc uses a camera system to read the ball’s seam orientation and adjust in real time.

“The camera takes a picture of the ball, it identifies the locations of the seams, and then reconfigures it into the desired orientation,” Pope said.

Since 2024, MLB has allowed players to use the machine during games, meaning a pinch hitter can face a simulation of an opposing closer moments before stepping to the plate.

“It does prepare guys that may come off the bench,” Mariners manager Dan Wilson said. “They get a chance to hit off the relievers that they may or may not see in that game.”

New Mariners infielder Brendan Donovan has become one of the club’s most frequent users. He views the machine as a way to make practice harder than the game itself.

“I’m a believer in almost like an overspeed training,” Donovan told Seattle Sports. “How can I make that as tough as possible? So hopefully when I get out there, it’s never going to get easier. You may just be able to make decisions a little quicker.”

The Mariners open their regular season on Thursday.

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