Fans of Major League Baseball have gotten used to a slew of rule changes that have taken effect across the game over the last couple of seasons. The added changes, such as the use of a pitch clock, bigger bases and expanded Wild Card teams in the postseason, have been met with mixed reactions since they were implemented, but the automated strike zone is sure to top that list possibly as soon as the 2026 season.
While the review system is still in its quality control phase, the Automated Ball-Strike (ABS) challenge system has been something that MLB officials have been testing out at the minor league level and independent ball ranks since 2019. This year, during spring training play, the challenge system will make its debut on a much bigger stage with 13 complexes in the Cactus League and Grapefruit League equipped with the technology to test the process out in real-time, with Philadelphia Phillies fans having their first glance at the process this spring.
MLB is going to test the Automated Ball-Strike (ABS) challenge system during Spring Training games.
— FOX Sports: MLB (@MLBONFOX) February 19, 2025
This was system was used in MiLB last year where calls challenged by players were overturned 51% of the time, per MLB.
What are your thoughts on the ABS Challenge System? pic.twitter.com/vraRdcf5WX
Phillies, BayCare Ballpark to host spring training games with ABS challenge system
The Phillies spring training home, BayCare Ballpark, is one of the 13 complexes that are currently equipped with an automated strike zone system called Hawk-Eye, a pitch tracking model that, according to MLB.com's Anthony Castrovince, sets the parameters for the strike zone at 17 inches wide, and adjusted to 27 percent and 53.5 percent height based on the size of the batter in the box.
While reliance on automated balls and strike calls is not yet part of the equation, the challenge system will give each team two chances to reverse calls on balls and strikes, with only the hitter, pitcher and catcher allowed to issue a challenge during an at-bat by tapping their helmet or baseball cap. Like the review process in the NBA, a successful challenge will result in a team holding onto future challenges, with unsuccessful reviews removing an opportunity to challenge a ball or strike call later in the game.
Want to see the automated balls and strikes system (ABS) in action?
— The Athletic MLB (@TheAthleticMLB) February 19, 2025
Here's Luis Gil challenging a call.
🎥 @ChrisKirschner pic.twitter.com/A5tYt6PAP4
While feelings remain split among baseball fans on removing the human element of umpires calling balls and strikes, veteran ball players on the Phillies will have a decent chance to familiarize themselves with the process this spring. While there's sure to be some controversy surrounding the process and some pushback via the Major League Baseball Umpires Association ahead of a wider implementation in regular-season game action, current Phillies catchers like J.T. Realmuto and Garrett Stubbs have a chance to see it play out in game action this spring, and that familiarity could be very helpful in close games as soon as the 2026 or 2027 seasons.