MLB to Launch Ball-Strike Review Challenges in 2026 Season

Major League Baseball will implement a challenge system based on Automated Balls and Strikes (ABS) next season, the league announced Tuesday.

The system was tested with some positive response from players this past spring training in Arizona and Florida.

“I don’t think it’s bad,” San Francisco Giants veteran pitcher Justin Verlander said then. “I definitely think it’s going to take some time to get it right, just like everything that’s been implemented in the game. We don’t know the ripple effects of it. But in the end, in big spots everyone wants the call to be right.”

The challenge system is not an automated umpire and does not call every pitch—the home plate umpire still has that duty. But the pitcher, catcher or hitter has the right to challenge a call at least twice every game. They can indicate it by tapping their cap or helmet immediately after the challenged pitch. There can’t be any help from any other player on the field or in the dugout.

The challenge is then analyzed and the results displayed on the main video board in each MLB ballpark, revealing whether the call is sustained or reversed.

If a challenge is successful, the team retains it. If it’s not, that team loses the challenge. In extra innings, a team will get one more challenge if it has none remaining.

The system has also been tested successfully in the minor leagues and the Arizona Fall League, which use the calls by the automated umps for every pitch.

Rather than implement the entire system, MLB has decided to start with just challenges first.

“It’s cool. I like it,” said Alek Thomas, an Arizona Diamondbacks outfielder who became used to it in their minor league system. “I wish we had more challenges. In the minor leagues, I tapped my head a lot if I didn’t agree with a call.”