Overview

• The Joint Competition Committee voted to adopt the ABS challenge system for all 2026 spring training, regular season and postseason games.
• Each team starts with two challenges that are retained if successful, with only the pitcher, catcher or batter able to initiate immediately by tapping the helmet or cap, and an extra challenge granted in each extra inning if none remain.
• Twelve Hawk-Eye cameras and a T-Mobile private 5G network will compare pitch locations to a two-dimensional strike zone 17 inches wide and vertically scaled to each batter’s certified height (top at 53.5% and bottom at 27%).
• MLB says trials produced roughly a 52.2% overturn rate and reviews averaging about 13–15 seconds after extensive testing in the minors, 2025 spring training and the All-Star Game.
• Human umpires will continue calling balls and strikes, and while MLB cites strong player preference for challenges, the MLBPA said the players’ committee vote was not unanimous.