Major League Baseball introduced the automated ball-strike system during opening weekend of the 2026 season, recording a 53.8% challenge overturn rate through the first games.

The overturn rate represented a slight increase from the 53% rate recorded during spring training. The new system allows teams to challenge ball and strike calls made by home plate umpires.

Teams varied in their use of the challenge system during the opening weekend. The Colorado Rockies made two challenges in their first three games of the season, while four teams made three challenges in their first three games. All teams experienced the new automated review technology during the first weekend of the 2026 season.