Central STL News

Major League Baseball will introduce the Automated Ball-Strike (ABS) Challenge System for all games starting in the 2026 season. The decision was made by the Joint Competition Committee, which voted to implement the technology after years of trials in Minor League Baseball, Spring Training, and this year's All-Star Game.

MLB Commissioner Rob Manfred said, "The previous rule changes that have been adopted by the Joint Competition Committee have had staying power and created momentum for the game. We used the same process with ABS that started with listening to fans, conducting extensive testing at the Minor League level, and trying at every step to make the game better. Throughout this process we have worked on deploying the system in a way that’s acceptable to players. 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."

The ABS Challenge System is designed as an alternative between full automation of ball-strike calls—sometimes referred to as “robot umps”—and traditional umpiring. Under this system, teams can request a review of certain ball or strike calls during a game.

The technology uses Hawk-Eye tracking and operates on T-Mobile's 5G private network. When a player challenges a call, Hawk-Eye’s data is transmitted almost instantly both to stadium videoboards and television broadcasts so that spectators can see whether a call is confirmed or overturned.

Mike Katz, president of marketing, strategy and products at T-Mobile, commented: "We’ve accomplished a lot through our longstanding partnership with MLB, and the rollout of ABS -- powered by T-Mobile 5G -- is one of our most exciting milestones yet. It’s a powerful example of how we’re using our technology to help MLB innovate, while preserving the character of the game we love. And it’s only possible with the scale and reliability of America’s Best Network."

Each team will start games with two challenges. In extra innings, if teams run out of challenges they will receive one additional challenge per inning beginning in the tenth inning. Challenges must be issued immediately by either the batter, pitcher or catcher—managers cannot issue challenges—and are signaled by tapping their cap or helmet.

During Spring Training 2025 when ABS was tested in 288 games, there were an average of 4.1 challenges per game; each review took about 13.8 seconds on average.

If a challenge results in an overturned call, teams retain their challenge; if not, they lose it. This introduces new strategic elements into gameplay regarding when to use available challenges.

Surveys conducted during Spring Training found that 72% of fans viewed ABS positively; 69% favored its adoption compared to continuing solely with human umpires.

The Challenge System has roots dating back to tests in independent leagues starting in 2019 and expanded use across various minor league levels through recent seasons. Fan feedback showed support for keeping some human element in umpiring rather than moving entirely to automated calls; fully automated systems led to more walks and slower games at lower levels.

At Minor League levels prior to 2025, MLB tested both two- and three-challenge limits per team per game; fan surveys indicated four total challenges per game as optimal.

During recent Spring Training games where ABS was used:

- Players challenged about 2.6% of called pitches.

- Overturn rates stood at roughly 52%.

- Defensive players succeeded slightly more often than hitters.

- Overturn rates decreased later in games.

For accuracy across different player heights, measurements are taken manually and then confirmed via biomechanical analysis before play begins.

This move marks MLB's first instance where home plate umpire decisions on balls and strikes may be reversed during regular season championship play.