MLB to Test Robot Umpires During Spring Training, Eyeing Regular-Season Use in 2026

Major League Baseball (MLB) is set to experiment with robot umpires as part of a challenge system during spring training across 13 ballparks, hosting 19 teams. This testing phase could potentially lead to the implementation of robot umpires during the regular season as early as 2026.

The league has been trialing the automated ball-strike system (ABS) in the minor leagues since 2019 but is still fine-tuning the shape of the strike zone. To use ABS in the major leagues, MLB would need to reach an agreement with the Major League Baseball Umpires Association, whose collective bargaining agreement expires on December 1st.

"I would be interested in having it in ‘26," said MLB Commissioner Rob Manfred after an owners' meeting. "We do have a collective bargaining obligation there. That's obviously a term and condition of employment. We're going to have to work through that issue as well." Manfred noted that the spring training experiment will need to be evaluated before MLB decides on future steps.

"There's two sides to that test," Manfred added. "It's what the clubs think about it and also what do the players think about it? And we're going to have to sort through both of those."

For the second consecutive season, Triple-A ballparks used ABS, but there is reluctance to strictly adhere to the strike zone defined in the rule book as a cube. MLB has been experimenting with modifications during minor league testing to find a more suitable solution.

Currently, the ABS calls strikes based on where the ball crosses the midpoint of the plate, 8.5 inches from the front and back. The top of the strike zone was increased to 53.5% of the batter's height this year from 51%, while the bottom remained at 27%.

During the first two and a half months of the Triple-A season, MLB used a split system: robot umpires alone for the first three games of each series and a human umpire with a challenge system for the final three. On June 25, MLB switched to an all-challenge system where a human umpire makes nearly all decisions.

​As MLB continues to explore the use of robot umpires, the upcoming spring training tests will play a crucial role in shaping the future of officiating in baseball. Both players' and clubs' feedback will be pivotal in determining whether ABS will become a permanent fixture in the major leagues. The league remains committed to improving the accuracy and fairness of the game while adapting to new technological advancements.