Major League Baseball may trial robot umpires with a challenge system during spring training next year, potentially paving the way for their use in the regular season starting in 2026.
Since 2019, MLB has been testing the automated ball-strike system (ABS) in the minor leagues, but is still refining the strike zone parameters.
At a recent meeting with the Baseball Writers’ Association of America, Commissioner Rob Manfred stated, “I mentioned at the owners meeting that we would unlikely introduce ABS to the major leagues without first testing it during spring training. If that’s the case for 2024, we would need to conduct the spring training test in 2025, assuming we resolve the current issues, which could make 2026 a possible year for its implementation. However, I won’t commit to that year just yet.”
Manfred acknowledged significant progress, noting, “The technology is accurate to a hundredth of an inch and performs excellently in tracking the ball’s path.”
Triple-A ballparks have used ABS for a second consecutive season, but there’s been limited interest in enforcing the strike zone as defined by the rule book, leading MLB to explore modifications during minor league trials.
Currently, ABS calls strikes based on the ball’s location as it crosses the midpoint of the plate, 8.5 inches from the front and back. This year, the top of the strike zone was adjusted to 53.5% of the batter’s height from the previous 51%, while the bottom remained at 27%.
Manfred added, “We still have technical issues related to defining the strike zone that need to be resolved.”
After initially using a robot umpire for the first three games of each series and a human umpire with a challenge system for the last three during the first 2.5 months of the Triple-A season, MLB transitioned on June 25 to an all-challenge system. In this setup, a human umpire makes nearly all decisions, with teams using challenges to review calls.
Currently, teams in the Pacific Coast League have three challenges each, while those in the International League have two. Teams retain their challenges if they are successful, following a similar process to that used in the major leagues for video reviews.
Tony Clark, head of the players’ association, noted earlier on Tuesday at a separate session with the BBWAA, “The challenge system is generally more favored than the straight ABS system. However, there are still concerns about how the strike zone will be managed, its consistency, and potential issues like Wi-Fi outages or technical failures.”
Clark added, “We are seeing these problems in minor league ballparks, and we want to avoid a situation in major league stadiums where there are more questions than answers about the game’s integrity and the accuracy of calls.”
Rule changes are reviewed by an 11-member competition committee, which includes four players, an umpire, and six team representatives. The committee implemented a pitch clock and defensive shift restrictions for the 2023 season without player support.
