"You're just getting more and more realistic views of what opposing pitchers have," catcher Riley Adams said of the Nationals' new Trajekt Arc machine. Sam Navarro / Imagn Images WEST PALM BEACH, Fla.

A holographic version of Miami Marlins starting pitcher Sandy Alcantara winds up to fire a fastball on the Trajekt ARC pitching machine Hours before the first pitch of a recent MLB game, Chicago Cubs ...