Major League Baseball is preparing to debut the Automated Ball‑Strike (ABS) Challenge System for the 2026 season, a hybrid that pairs Hawk‑Eye’s tracking precision with T‑Mobile’s connectivity to bring a limited form of fan‑driven review to the game.
How the challenge works
Only the batter, the pitcher and the catcher can initiate a challenge, and each team begins a game with two such attempts. A second unsuccessful challenge removes the right to challenge for the remainder of that game, but every extra inning grants a fresh chance, ensuring that late‑game drama still has a voice.
The system relies on Hawk‑Eye’s high‑speed cameras to capture the ball’s trajectory the instant it crosses the front of home plate. T‑Mobile’s network carries the data in real time to the league’s central review hub, where the strike zone is calculated using the batter’s height without cleats.
Defining the strike zone
The zone’s width is fixed at 17 inches, the exact width of home plate, while its top and bottom are set at 53.5% and 27% of a player’s height, respectively. This dynamic definition aims to reflect each hitter’s unique stance, creating a more personalized and, officials say, fairer assessment of what constitutes a strike.
Because the technology tracks the ball as it passes through the middle of the plate, the system can lock in the strike zone the moment the pitch is released, reducing the reliance on human judgment in real time.
A notable restriction is that challenges are not permitted when a position player is on the mound. This rule preserves the traditional distinction between pitching and fielding roles while still allowing the automated system to operate consistently.