The new computerized system is being tested during spring training, leading to a series of challenges from players who don’t know the strike zone quite as well as they think.

Though this hybrid umpire system won’t make its way to regular season major league games in 2025, player and fan reactions during this crucial trial period could determine whether or not it becomes a regular staple in games.

The batter, pitcher or catcher simply tap their helmet or cap to challenge — but they only have two seconds. If they challenge, the pitch graphic appears on the scoreboard and broadcast, and the umpire updates the count. The MLB says this takes about 17 seconds.