MLB ABS Challenge System Explained: How Automated Ball-Strike Challenges Work in Baseball
Saw a hitter, catcher, or pitcher tap their helmet after a pitch and wondered what just happened. Here’s a clear guide to MLB’s ABS challenge system, including who can challenge, how many challenges teams get, and how the strike zone is judged.
MLB ABS Challenge System Explained: How Automated Ball-Strike Challenges Work in Baseball originally appeared on NESN . Add NESN as a Preferred Source by clicking here . If you are watching a game and suddenly see a batter, catcher or pitcher tap their helmet after a borderline pitch, that is MLB’s ABS challenge system in action.
“ABS” stands for Automated Ball-Strike system , but in the majors it does not mean full-time robot umpires calling every pitch. Instead, the plate umpire still makes the original call, and players can challenge certain ball-or-strike calls for a near-instant review. MLB approved the system for Major League play beginning in 2026, and it is now used in spring training, the regular season and the postseason.
What is the ABS challenge system? Mark J. Rebilas-Imagn Images The simplest way to think about it is this: MLB kept the human umpire, then added a limited challenge system for obvious misses.
If a pitcher, catcher or batter thinks the umpire got a ball-or-strike call wrong, that player can challenge it immediately. A Hawk-Eye camera system tracks the pitch, compares it to the batter’s assigned strike zone, and the result is shown on the scoreboard and broadcast. The review takes about 15 seconds.
Continue to the original source for the full article.