Major League Baseball will use so-called robot umpires at home plate beginning in 2026, the league announced today. The system has been tested in minor league games (as explained in this video, included below), spring training, and events like the 2025 All-Star Game.
The Automated Ball-Strike System (ABS) is seen as a fairer, more accurate way to call when a pitch is a ball or a strike, which currently is done by the home plate human umpire. A pitch is a ball when it’s thrown outside the strike zone and a strike when it’s within the zone, but home plate umps are frequently the target of ire when they make bad calls. The strike zone varies for individual players based on their stance and size.
ABS won’t totally replace human umpires — it’s only called in when a player challenges an umpire’s call. Each team gets two challenges a game, and the only players who can request an ABS review are the pitcher, catcher, and batter. A team doesn’t lose a challenge if a player requests one and the call is overturned. MLB says the process takes 15 seconds and made sure to note that it “will certify each player’s official height” to ensure an accurately determined strike zone.
Using ABS for challenges feels somewhere in the middle of relying on human umpires and going all-in on an automated system. “The strong preference from players for the Challenge format over using the technology to call every pitch was a key factor in determining the system we are announcing today,” said baseball commissioner Rob Manfred.
As The Athletic reports, how players respond to the new system might depend on what position they play or the situation the player is in (if it’s a full count, bases loaded, your strategy is probably going to be different than if it’s a less consequential call). There’s also the more philosophical question of what ultra-precise technology does to a game that is sometimes frustrating for everyone involved: does litigating the last quarter inch of a strike zone make baseball more or less fun? I suspect just about everyone both benefits from and gets screwed by bad calls once in a while, maybe in equal measure. We’ll see how the system feels next season.
In the meantime, MLB released a few interesting statistics from the test during spring training:
