Changes are coming to Major League Baseball in 2026.
The league’s 11-man competition committee approved the use of the automated ball/strike system (ABS) on Tuesday. The robot umps will be used for the entire 2026 season.
A human umpire will still make calls for balls and strikes behind the plate. If a team wants to appeal, a computer will then make the call whether it was a ball or strike.
Stadiums are outfitted with cameras that track each pitch and judge whether it crossed home plate within the strike zone. In early testing, umpires wore ear buds and would hear “ball” or “strike,” then relay that to players and fans with traditional hand signals.
The technology has been used in the minor leagues since 2019, with the 2024 season being the second consecutive year every MiLB park using the robot umps.
It was also used during spring training this year, and at the 2025 MLB All-Star Game. Four of five challenges of home plate umpire Dan Iassogna’s calls were successful.
Here’s how the ABS system will work, via MLB:
Each team will get two challenges and can keep them if they’re successful
Challenges can only be initiated by a pitcher, catcher, or batter, and the request must come right after the pitch
To signal a challenge, the pitcher, catcher, or batter will tap his hat or helmet to let the umpire know
No help from the dugout or other players on the field is allowed
In each extra inning, a team will be awarded a challenge if it has none remaining entering the inning
MLB estimates the process, on average, takes about 17 seconds.
Success rate have hovered around 50% in the minors. At Triple-A this season, the success rate dropped to 49.5% from 50.6%. Defenses — usually catchers — have been more successful, winning 53.7% of challenges compared to 45% by batters. Challenges increased to 4.2 from 3.9 per game through Sunday.
The Associated Press contributed to this article