Rob Manfred: Robot referees could be put to the test in spring training

ARLINGTON, Texas — Major League Baseball hopes to test robot umpires as part of a challenge system during spring training next year, making an automated ball-striking component possible as early as 2026. But MLB Commissioner Rob Manfred appeared far from committing to that date, saying Tuesday that the league has “technical issues with the definition of the strike zone” that need to be resolved before it can even be tested by major league players.

“We need 2025 to do the spring training test if we can work through these issues, which will make 2026 a viable possibility,” Manfred said at his annual pre-All-Star meeting with the Baseball Writers’ Association of America (BBWAA). “Will this be the year? I’m not going to be indifferent to that issue.”

MLB has been experimenting with an automated ball-striking system, or ABS, at the minor league level for five years and began using it at all Triple-A ballparks in 2023. Initially, half the games used ABS for every call and the other half used the challenge system, but MLB switched exclusively to a challenge system — in which the plate umpire calls balls and strikes as usual and teams have a limited number of calls that can be reviewed — on June 25.

According to Manfred, the change is “almost 100 percent” based on player feedback, who prefer a challenge system to a full ABS system. Manfred added that the ABS’s accuracy is “good to a hundredth of an inch” and the ball flight technology is “perfect” – but it’s not quite ready yet.

“One thing we learned with the changes last year is that a little more time is better than not enough,” Manfred said. “And by that I mean making sure that when you bring something to the big leagues, you make sure you do it right.”

The rule changes are subject to an 11-member competition committee, comprised of an umpire, four players and six team representatives, which gives MLB the most say when it comes to implementing new rules — which it used to incorporate a pitch clock, larger bases and restrictions on infield changes ahead of the 2023 season. Players have already expressed frustration that their input on the new rules has not been fully heard, particularly regarding the new pitch clock limits in 2024.

Another issue is the umpires’ collective bargaining agreement that expires at the end of the 2024 season, and MLB’s willingness to implement an ABS is expected to be a major part of the negotiations. Tony Clark, executive director of the MLB Players Association, called the players’ input on the ABS “interesting.”

“There are those who have no interest in it at all, there are those who have concerns about the contest system, how the strike zone itself will be viewed, what it looks like, how consistent it will be, what happens in a world where Wi-Fi goes down in a stadium or technology acts up on any given night,” Clark said in a previous session with the BBWAA. “We see these issues even in minor league stadiums. We don’t want to be in a world where, in a major league stadium, we’re left with more questions than answers about the integrity of that night’s game or the decisions that go into it.”