Major League Baseball will introduce a robot umpire challenge system for balls and strikes in the 2026 season, following years of testing in the minors, spring training, and the All-Star Game.

Teams will receive two challenges per game, triggered by hitters, pitchers, or catchers tapping their heads, with successful challenges displayed on in-stadium videoboards.

The automated ball-strike (ABS) system uses 12 cameras per ballpark, tracking pitches with roughly one-sixth of an inch accuracy, and defines the strike zone by a player’s height and the plate’s full width.

Extra-inning rules allow teams additional challenges, and spring training tests showed catchers had the highest overturn rate at 56%, followed by hitters at 50% and pitchers at 41%, ESPN has reported.

MLB hopes the system will preserve umpires’ roles, improve call accuracy, and reduce ejections, which are largely related to disputed balls and strikes.