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What is ABS? Explaining MLB's newest rule change before Opening Day
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- What is ABS? Explaining MLB's newest rule change before Opening Day
Major League Baseball has made some serious changes to the sport in recent years. From the universal DH to replay challenges to pitch clocks, and 2026 will be no different. This year, the league is introducing the ABS (Automated Ball-Strike) system thereby giving more power to the players.
Umpires have previously worked with virtual impunity, only subject to criticism from people on social media detailing their mistakes when it came to ball and strike calls. For all of time, whatever they said, went. However, that will no longer be the case in 2026. The ABS challenge system will give players the opportunity to challenge an umpire's ball or strike call, and given how vastly different players perform in 0-1 vs. 1-0 counts, this could lead to some game-changing scenarios.
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And with Opening Day just hours away, we are ever so close to seeing it play out. Here's everything to know about the new ABS challenge system.
Los Angeles Angels right fielder Jo Adell returns to the dugout after he was called out on strikes during the fourth inning against the Los Angeles Dodgers at Dodger Stadium.
What is ABS?
ABS is an automated system that uses 12 cameras to depict exactly where each pitch crosses home plate. It has been used in the minor leagues since 2021, debuting in the Arizona Fall League and Low-A Southeast League before slowly being implemented into more and more minor league stadiums. Though the first baseball organization to use the system was the independent Atlantic League back in 2019.
Teams were allowed to experiment with the system during spring training this year.
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How does the challenge system work?
Each team is granted two challenge opportunities at the start of each game. Throughout the contest, only the pitcher, batter and catcher can challenge pitches and they must indicate that they are challenging a call immediately after the call is made by tapping their helmet/hat.
If the challenge is successful and the call is overturned, the team retains that challenge. If the challenge is unsuccessful, the team loses that challenge for the rest of the game.
If a game goes into extra innings and all challenges have been depleted, the team will be granted one additional challenge opportunity per extra inning played, meaning they will get one for the tenth, one for the eleventh, and so on.
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How accurate is ABS?
Very.
Although not 100% accurate, the system is close, but requires exact inputs for each batter's height in order to properly create a strike zone. According to MLB.com , the strike zone sits at between 27% and 53.5% of a player's height, very precise dimensions. All MLB players were re-measured prior to spring training in order to get more updated height figures.
This article originally appeared on USA TODAY: What is ABS? Explaining MLB's latest rule change before Opening Day
