‘Good to 100th of an inch’: US baseball league could deploy robot empires by 2026

Major League Baseball (MLB) is considering implementing robot umpires, known as the Automated Ball-Strike (ABS) system, as part of a challenge system in spring training next year.

If successful, this technology could be introduced in regular-season games by 2026. MLB has been testing the ABS in minor leagues since 2019, but it still faces challenges regarding the definition of strike zone.

Commissioner Rob Manfred recently discussed this during a meeting with the Baseball Writers’ Association of America, highlighting the importance of a spring training test before introducing ABS to the major leagues.

“I said at the owners meeting it is not likely that we would bring ABS to the big leagues without a spring training test. OK, so if it’s ’24 that leaves me ’25 as the year to do your spring training test if we can get these issues resolved, which would make ’26 a viable possibility,” Manfred said.

“But is that going to be the year? I’m not going to be flat-footed on that issue.”

Testing and technical challenges

MLB has made significant progress with the ABS, which is currently accurate to a hundredth of an inch. The technology effectively tracks the ball’s path, but unresolved technical issues still surround the strike zone’s definition.

Manfred noted , “We have made material progress. I think that the technology is good to a 100th of an inch. The technology in terms of the path of the ball is pluperfect.”

The ABS system has been used in Triple-A ballparks for two consecutive seasons, but MLB has been hesitant to implement the strict cube-defined strike zone described in the rule book. Instead, MLB has experimented with modifications during minor league testing.

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

“We do have technical issues surrounding the definition of the strike zone that still need to be worked out,” Manfred acknowledged.

Earlier in the Triple-A season, MLB experimented with a split approach. The first three games of each series used the robot umpire alone, while the final three games combined a human umpire with a challenge system.

On June 25, MLB switched to an all-challenge system in which a human umpire makes nearly all decisions. Still, each team has limited challenges—three in the Pacific Coast League and two in the International League. If successful, teams retain their challenges, similar to video review regulations for big league teams.

Players’ concerns and committee approval

The challenge system has garnered more support than the straight ABS system, but some players remain skeptical. Tony Clark, head of the players’ association, expressed concerns about the consistency of the strike zone and potential technical issues.

“The challenge system is more likely or more supported, if you will, than the straight ABS system,” Clark said .

“There are those that have no interest in it at all. There are those that have concerns even with the challenge system as to how the strike zone itself is going to be considered, what that looks like, how consistent it is going to be, what happens in a world where Wi-Fi goes down in the ballpark or the tech acts up on any given night.”

Clark added, “We’re seeing those issues, albeit in minor league ballparks. We do not want to end up in a world where in a major league ballpark we end up with more questions than answers as to the integrity of that night’s game or the calls associated with it.”

Playing rules changes are subject to approval by an 11-member competition committee, which includes four players, an umpire, and six team representatives. The committee adopted a pitch clock and restrictions on defensive shifts ahead of the 2023 season without player support.

The introduction of the ABS system will likely face a similar process, balancing technological advancements with player and umpire concerns to preserve the integrity of the game.