Philly Leader

Major League Baseball (MLB) is set to test an Automated Ball-Strike System (ABS) during the upcoming Grapefruit and Cactus League seasons this spring. The system, presented by T-Mobile, will be implemented in approximately 60% of Spring Training games as MLB evaluates its suitability for the Major League level.

“This is a pretty big decision for the game of baseball,” said Morgan Sword, MLB executive vice president of baseball operations, “that we want to get everybody to weigh in on.”

The ABS challenge system allows players to contest ball or strike calls made by human umpires using Hawk-Eye technology. This technology monitors pitch locations relative to the batter’s strike zone. Each team will start with two challenges per game during Spring Training 2025.

Challenges can only be issued by the batter, pitcher, or catcher immediately after an umpire's call. If a challenge is successful, it is retained; otherwise, it is lost. The review process adds an average of 17 seconds to game time based on Minor League testing.

The system was first used in the independent Atlantic League in 2019 and has since been tested at various levels of Minor League Baseball (MiLB). Testing showed a preference among fans and players for maintaining some human element in umpiring rather than fully automated systems.

“In no strike zone that we’ve tried, in no format that we’ve tried,” said Sword, “has that rate moved much above or below 50%, which is pretty interesting in that these are the subset of pitches that are most ‘controversial’ among players.”

Hawk-Eye technology will be available at several Spring Training ballparks across Arizona and Florida. These include facilities like Salt River Fields and TD Ballpark among others.

The ABS challenge system aims to balance traditional umpiring with technological accuracy without drastically changing the sport overnight. It provides a strategic element by allowing teams to decide when best to use their limited challenges.

As part of this experiment, MLB will also explore different ways of displaying strike zones on broadcasts during Spring Training games to prevent teams from gaining an unfair advantage through televised graphics.