Mar 26, 2026 - Major League Baseball players gained the right to challenge home-plate umpires' balls and strikes calls this season under the new Automated Ball-Strike Challenge System.
Beginning with the 2026 regular season, which opened Wednesday with the New York Yankees against the San Francisco Giants, each team starts with two challenges per nine-inning game. Pitchers, catchers or batters can initiate a challenge immediately after a pitch by tapping their helmet or hat. The umpire acknowledges the request, and the system reviews the pitch location using Hawk-Eye camera technology. Results appear on stadium videoboards and television broadcasts via a 5G network provided by T-Mobile.
Successful challenges do not count against a team's total, allowing continued use of remaining challenges. In extra innings, teams receive at least one challenge per inning. Dugout personnel cannot assist in deciding whether to challenge. The system, tested in the minor leagues since 2022 and in major league spring training, uses a standardized two-dimensional rectangular strike zone based on each batter's height.
The Joint Competition Committee, composed of owners, players and an umpire, approved the system last September after years of discussion. Human umpires continue to make initial calls on every pitch. The change aims to address long-standing disputes over ball and strike accuracy while preserving elements of the traditional game.
The ABS Challenge System has already appeared in the season opener, with the first challenge occurring on March 25. Data from minor league tests and spring training showed challenges overturned calls slightly more than half the time in some samples. MLB officials have noted that the automated zone is slightly smaller than the average human-called zone in recent seasons, which could modestly affect walk and strikeout rates.
Umpires retain authority over other aspects of the game, including check swings and other rulings. The technology transmits pitch data over stadium networks for near-instant review without significantly slowing play.
As of Thursday, the system operated in all major league games without reported technical issues. MLB continued monitoring its implementation, with no immediate plans announced for further adjustments to the challenge limits or procedures.
