Under MLB’s 2026 Automated Ball-Strike Challenge System, each team started with two ABS challenges. The system gave players a way to appeal selected ball-and-strike calls while keeping the home-plate umpire as the game’s primary decision-maker.
A pitcher, catcher, or batter could initiate a challenge immediately after a pitch by signaling. The automated system then reviewed the pitch’s location relative to the strike zone. If the challenge overturned the umpire’s call, the team retained it; an unsuccessful challenge was deducted from its total. This means a team could make more than two challenges in a game if it won some of its appeals.
The 2026 system was different from traditional video replay challenges, which cover plays such as tags, force plays, and boundary calls. ABS challenges focused specifically on ball-and-strike decisions. In extra innings, teams could receive another challenge under the league’s special extra-inning provision, so “two” describes the starting allotment rather than necessarily the maximum possible number.