It’s March 26, 2026, MLB’s opening night. You just sat down to watch your favorite team play after a handful of baseball-less months. About halfway through the game, your favorite player is up at bat, the count is 2-2, two strikes and two balls, and you’re on the edge of your seat. Will he strike out? Hopefully not. The pitcher winds up and throws.
“STRIKE,” the umpire yells.
That pitch looked a little outside the strike zone to you. You’re frustrated, but not surprised. After all, this is typical baseball.
However, the hitter does not walk back to the dugout as he normally would. Instead, he taps his helmet a few times. What is this? Is he patting his head in anger? Is he doing some sort of war cry for benches to be cleared over this infuriating call? Comforting his ego?
None of the above. This is the initiation of the Automated Ball-Strike system (ABS).
The ABS allows a catcher, pitcher, or batter to challenge an umpire’s call of a strike or ball. By tapping their hat or helmet, a player indicates that they want the call to be reviewed
The contentious call is reviewed by a network of 12 cameras, which each track the ball’s velocity, spin, movement and position. The data is used to determine the pitch’s location relative to the player’s strike zone. The video is displayed almost instantaneously on the screen and broadcast for fans to view. The umpire’s call of ball or strike is then either confirmed or overturned.
At the start of each game, each team holds two challenges. If a team wins a challenge (meaning the umpire’s call is overturned), they gain back the challenge. If they lose a challenge (meaning the umpire’s call is confirmed), they lose that challenge.
While the ABS was officially introduced for the MLB regular season on opening night, it is not a new system within baseball.
In 2022 the Florida State League, a Single-A minor league, the lowest level of the four full-season levels of Minor League Baseball, used the challenge system for the first time. Triple-A, the highest level of Minor League Baseball, tested both the ABS challenge system, where each team possesses two challenges, and full ABS, where an electronic network calls every pitch, during the 2023-24 season. Following this, the full ABS was pushed aside and the challenge system was tested during 2025 MLB spring training for final approval.
Now, with the end of the 2026 MLB regular season in sight, it seems fitting to examine the outcomes, concerns, and lessons learned from ABS’s inaugural season in such a timeless sport.
As of September 3rd, overall, catchers win the most challenges, with an overturn rate of 58.5% across the league. Batters sit behind that at 48.7%, and pitchers are in last place with an overturn rate of 40.9%.
Because catchers must track where pitches land relative to the strike zone, they have an advantage in knowing which calls are worth challenging. Meanwhile, pitchers and batters have a less straightforward view of the pitch, making it more difficult to find consistency and accuracy in challenging.
Paul Blackburn, relief pitcher for the New York Yankees and Davis Martin, starting pitcher for the Chicago White Sox, state that both leave most, if not all, challenges up to their catchers. Martin told ESPN he “trust[s] the catchers to do what they need to do back there.”
The batter with the best overturn rate across the entire league (56.5%) is rookie Sal Stewart, first baseman for the Cincinnati Reds. Stewart’s teammate behind the plate, Reds catcher Tyler Stephenson, has the league-wide best overturn rate amongst catchers (68.9%), making Cincinnati an unlikely hotspot for successful challenges.
When asked about ABS, Reds players explained that two months into the season they began strategically using challenges early in the game. This strategy allows catchers like Stephenson to use challenges to expose umpires strike-zone tendencies early, potentially signaling where they consistently miss calls and influencing subsequent calls “back onto the plate,” as TJ Friedl, Reds center fielder, put it.
Across the league, most teams win roughly half of their challenges. On the batting side, the Reds once again take the lead, possessing the highest team overturn percentage of 57%, while the Atlanta Braves sit at the bottom with an overturn percentage of 40%.
Meanwhile, on the fielding side, including pitchers and catchers, all teams except the Chicago White Sox and Pittsburgh Pirates hold an overturn rate over 50%, with the Chicago Cubs holding the highest percentage at 68%.
Using more challenges does not necessarily equate to more overturned calls. The Chicago White Sox have the most fielding challenges league-wide (237), yet hold the lowest team overturn rate at 49%. Meanwhile, the Texas Rangers challenge at a rate almost half that of the White Sox, yet they hold an overturn rate of 65% from the field.
Success with the ABS and challenges requires selection and strategy, rather than just frequency. Overall, teams have more success challenging calls from the field rather than the batter’s box, perhaps due to catchers’ keen eyes behind the plate
Most players who were asked about the system hold a positive view of it. In an interview with ESPN, Adley Rutchsman, catcher for the Boston Red Sox, expressed that ABS “brings a new aspect to the game,” pushing teams to consider the correct times to challenge and their confidence.
Francisco Lindor, shortstop for the New York Mets, points to the entertainment value ABS adds for fans, telling JM Baseball that “it gets the fans involved a little bit more.” Rico Garcia, reliever for the Baltimore Orioles, echoes Lindor, noting that the system adds a new type of interaction for fans.
However, a few players have voiced concerns with ABS and its effects on length of play and baseball purity.
Ernie Clement, Toronto Blue Jays second baseman, is outspoken about his lack of support for the system, stating that he believes “it slows the game down.” Yet, the average game saw just under a minute of added time with the use of ABS in 2025 spring training.
Max Scherzer, Toronto Blue Jays starting pitcher, expresses a more traditionalist view, arguing that the system takes away from the “human element of the game.” Others, however, point out that there are still umpires making every call, and interacting with both batters and catchers. Ultimately, the ABS is in place in order to prevent erroneous calls from affecting game outcomes, not to replace umpires.
Fans and players have expressed the desire for more than two challenges. However, Minor League experiments coupled with fan surveys suggest that adding a third challenge would create more pauses, with the two-challenge system aligning with fans preferred length of play.
So, is ABS legit, or is it a BS challenge?
After its inaugural season, the answer seems to be closer to the former. The numbers imply the system has been performing as intended: giving teams an opportunity to fix calls without completely uprooting the flow of play. Players have largely embraced the added layer of strategy, fans have found excitement in watching challenges, and it has only minimally increased game length.
So for now, the head (or helmet) taps will continue. Whether you find yourself moaning over a confirmed call, or celebrating an overturned one, one thing remains clear: the ABS has found its place in baseball.
