A tap of the cap or helmet has new meaning in 2025 spring training games.

In more than 55 percent of spring training games over the next six weeks, Major League Baseball is employing the Automated Ball-Strike System, granting each team two challenges of called balls or strikes in real time.

Reviews triggered by a batter, catcher or pitcher must be made immediately after the home plate umpire calls or signals ball or strike. Managers and players in the dugout cannot call for a review.

Once prompted, the review, or a digitalized replay common on broadcasts, is shown to the umpire and replicated on stadium video boards using Hawk-Eye Technology. Viewers of broadcast feeds will also see the same replay, according to MLB, which said its research revealed that a strike zone challenge typically added 17 seconds to a game.

When used during minor league games in 2024, 51 percent of player-requested challenges were successful, meaning the original ball or strike call was overturned.

ABS uses precise measurements — home plate 17 inches wide, top of the strike zone 53 percent of a batter’s height, bottom of the zone is 23 percent of a batter’s height — to overlay a laser-like digitized strike zone in a not-for-broadcast tracker of every pitch. When a challenge is granted, the replay of the tracker is shown instantly.

Biomechanical analysis of team height measurements were confirmed by the Southwest Research Institute to provide exact player dimensions with a goal of a precisely uniform strike zone for every batter. The depth of the zone, often the source of questioning of balls and strikes on offspeed and breaking pitches, is flat and uniform for every batter: 8.5 inches from the front and back of the plate.

The system was used in the Independent Atlantic League in 2019. Starting in 2023, most Triple-A stadiums were outfitted with the technology for fully automated balls and strikes, or robo umps, and the ABS challenge system MLB opted to trial this spring.

Root systems of the technology are widely known for the application within Statcast products to track ball flight, pitch location, type and speed, bat speed, exit velocity and distance a batted ball travels.

The ABS challenge system will also be used in the minor leagues in 2025. There is no plan to quickly adopt challenges for ball-strike calls for the 2025 MLB regular season.

Unless MLB adds technology during spring training, there are 13 ballparks equipped with required tech and video replay pairings to participate in the challenge system trial and 10 sites that won’t be involved.

In the Grapefruit League, these Florida spring training sites are planning to use the challenge system: TD Ballpark (Blue Jays), BayCare Ballpark (Phillies), George M. Steinbrenner Field (Yankees), Publix Field at Joker Marchant Stadium (Tigers), LECOM Park (Pirates), Hammond Stadium (Twins), Clover Park (Mets) and Roger Dean Chevrolet Stadium (Cardinals and Marlins).

In Arizona, the Cactus League sites ready for ball-strike challenges are the Peoria Sports Complex (Padres, Mariners) Salt River Fields (Diamondbacks, Rockies), Camelback Ranch (Dodgers, White Sox), Surprise Stadium (Rangers, Royals) and Goodyear Ballpark (Guardians, Reds).

–Field Level Media