Overview

• MLB’s 11-member Joint Competition Committee approved ABS for use across spring training, the regular season and the postseason starting in 2026, with passage enabled by an owners’ majority.
• Teams will start each game with two challenges, keep successful ones, and receive one additional challenge in each extra inning if they have none; only the pitcher, catcher or batter may challenge immediately with no dugout input.
• The system uses a network of Hawk‑Eye cameras over a T‑Mobile private 5G connection, displaying challenge results on ballpark boards and broadcasts in roughly 15–17 seconds on average.
• ABS applies a two‑dimensional rectangular zone spanning home plate’s 17-inch width, with the top at 53.5% and bottom at 27% of each batter’s height, judged at the plate’s midpoint.
• After multi‑year tests in the Atlantic League, Triple‑A, 2025 spring training and the All‑Star Game, challenges averaged about four per game with success rates near 50–52%, and MLB had already laid CBA groundwork with umpires to enable adoption.