The Major League Baseball (MLB) season started March 25 and many fans have noticed a different rule in place: the Automated Ball-Strike (ABS) System. ABS allows the pitcher, catcher or batter to challenge the call of a ball or a strike, changing a large aspect of the game.
ABS was first introduced in 2022 to Minor League Baseball. It slowly made its way to MLB Spring Training and the MLB All-Star Game during the 2025 season. In September 2025, MLB’s Joint Competition Committee approved the ABS Challenge System for the 2026 MLB season.
“I first heard about it [ABS] when it was introduced to minor leagues about three years ago. I honestly didn’t know what to think because it’s such a game changer,” Ethan Trivison, senior baseball player, said.
There has been a long-standing issue with human error in baseball. ABS erases a part of that, by improving accuracy, fairness and accountability in calling balls and strikes. It’s used to find a middle ground; umpires can control most of the game, but players have the opportunity to overturn incorrect calls.
“Umpire calls before were never perfect, and could lead to tension, but the control they had before ABS was a massive part of the game,” Trivison said.
To challenge a call, players tap their hat/helmet. The play is then reviewed using camera data and is displayed on the scoreboard. Each team starts with two challenges a game. If a team uses their challenge and is proven to be correct the call is overturned and the team gets to keep the challenge. If the team uses their challenge and the original call was revealed to be correct, then the team loses that challenge.
The first challenge this season occurred on Opening Day during the fourth inning of the New York Yankees and San Francisco Giants game. Jose Caballaro, Yankees shortstop, challenged a strike call, which was upheld.
MLB teams are using different strategies to take advantage of ABS. Some being aggressive, others holding their challenges until the end of the game. The Boston Red Sox have a clear strategy.
“The most important thing is when (we challenge), we don’t want to be the team that challenges the most. We want to be the most efficient,” Red Sox manager Alex Cora said in a postgame interview with reporters, per Seattle on Tap, following their usage of challenges in their April 2nd game.
Other teams, like the Cleveland Guardians, are using a more conservative approach.
“It’s more about how many we can get right than it is our percentage. Whether you’re 2-for-100 or 2-for-2, you got two challenges overturned. We want our guys to use them,” Guardians manager Stephen Vogt said in an interview with the New York Times,
The San Diego Padres keep a challenge play sheet in their dugout which outlines situations when a hitter should be more and less aggressive in challenging pitches.
“Pitchers definitely have it the hardest. They can’t get away with calls anymore,” Waylon Hassett, freshman baseball player, said.
Although umpire mistakes are rare, they can make or break the momentum of a pitcher, the team, and even the whole game.
“It creates a little more stress on my nights. I’m constantly second-guessing myself,” Philadelphia Phillies catcher J.T. Realmuto said in a conversation with OnPattison.
The future of ABS still seems unclear as it’s still early in the season, but teams and players have expressed their hopes for it to be beneficial.
“Overall, the ABS system is a great addition to the game and ensures fair calls for both sides,” Trivison said.
