The 2026 baseball season is underway, which means that the Automated-Ball Strike (ABS) Challenge System, powered by T-Mobile, is getting its first official use at the Major League level.
In light of the historical significance, MLB.com will be keeping a running list of ABS firsts -- beginning, of course, with the first challenge ever issued in a regular season Major League Baseball game.
ABS Challenge System, powered by T-Mobile
• See what happened on the first-ever ABS challenge
• Everything you need to know
• A visual guide to how ABS works
• Here are Major League Baseball's ABS firsts
• What does all the data mean
• Players get strike zones measured
• Player poll: Who'll be best at ABS challenges?
• ABS Challenge Dashboard
• ABS Challenge Leaderboard
First challenge
Date: March 25, 2026
Game: Yankees at Giants (4th inning)
Player: José Caballero (NYY), batter
The first official ABS challenge was issued by Yankees shortstop Caballero on a first-pitch called strike from Logan Webb. The call on the field was upheld.