Teams start with two challenges per game in MLB’s ABS challenge system. In extra innings, a team is guaranteed at least one challenge , even if it already used both in regulation.

Quick scoop

Only the pitcher, catcher, or batter can challenge a pitch, and they have to do it almost immediately after the pitch. MLB’s 2026 rules were set up this way to keep the system fast while still giving teams a couple of chances to dispute key ball-strike calls.

Extra innings

If a game goes to extras, teams that have no challenges left get one new challenge each inning in extra innings. If they still have a challenge available, they keep it for the next eligible situation rather than stacking more than one per inning.

Why it matters

MLB experimented with different challenge counts in the minors, and the league settled on two because it balanced accuracy with pace of play. In Spring Training, ABS challenges averaged about 4.1 per game across both teams, which helped MLB gauge how often the system would actually be used.

If you want, I can also give you the exact ABS challenge rules in one simple list.