Human plate umpires will still call balls and strikes, but teams can challenge two calls per game and get additional appeals in extra innings. The Automated Ball-Strike Challenge System, powered by T-Mobile, is coming to MLB's Regular Season ⚾️ https://t.co/97raRHFtsT pic.twitter.com/SHxKuRTKu8 — MLB (@MLB) September 23, 2025ABS, which utilizes Hawk-Eye cameras, has been tested in the minor leagues since 2019. The independent Atlantic League trialed the system at its 2019 All-Star Game and MLB installed the technology for that year's Arizona Fall League of top prospects. MLB switched Triple-A to an all-challenge system on June 26, 2024, then used the challenge system this year at 13 spring training ballparks hosting 19 teams for a total of 288 exhibition games. The challenge system introduces ABS without eliminating pitch framing, a subtle art where catchers use their body and glove to try making borderline pitches look like strikes.