MLB Introduces Minor League Rule Experiments for 2026

Major League Baseball will introduce several experimental rule changes across its minor league system for the 2026 season, aiming to refine umpiring decisions, enhance player development and pace of play, while promoting more aggressive baserunning.

The most prominent adjustment involves challenges to checked swing calls, expanding from lower levels to the Triple-A Pacific Coast League starting May 6. Under the new system, batters, pitchers or catchers can appeal an umpire's checked swing decision using automated ball-strike challenge technology. A swing is deemed to have occurred if the bat head exceeds a 45-degree angle relative to the handle, aligning roughly with the foul lines from home plate. This threshold, tested last year in the Class A Florida State League and Arizona Fall League, resulted in a 3 percent drop in strikeout rates there, as more borderline calls favored hitters and increased balls in play.

In the Triple-A International League, umpires will apply the same 45-degree standard for checked swings starting May 6, but without the option for challenges, creating a comparative test between the two top minor league circuits. The Florida State League will implement...