Robots will start assisting MLB umpires, but the human element still plays a crucial role.
But here’s the important twist: the machines are powerful, yet human judgment remains essential. Rockies manager Warren Schaeffer, who has seen the Automated Ball/Strike (ABS) system in action, knows there’s more to the game than data and cameras. “I’ve seen decisions misfire in the first inning,” he noted. “Emotion matters.”
ABS made its first big-league appearance during last year’s spring training, drawing curiosity, skepticism, and cautious optimism. Now, with 2026 regular-season games underway, teams are turning curiosity into strategy. MLB shared insights about ABS at a Cactus League Media Day in Arizona. Joe Martinez, MLB’s vice president of on-field strategy, cited a fan survey: 52% of fans described ABS as “very positive” for last spring, 20% called it “slightly positive,” and 18% said it didn’t affect the game. Only 10% felt ABS had a negative impact, either slightly or strongly.
Here’s a refresher on how ABS works: Stadiums install cameras that track each pitch and determine whether it lands within the strike zone. Umpires still call every pitch, but each team may challenge two calls per game. If a challenge is used, a team can earn an extra challenge in each extra inning if successful, mirroring the existing video-review framework. A successful challenge preserves the team’s right to challenge again, as with past rules for home run reviews introduced in 2008 and expanded in 2014.
Only batters, pitchers, or catchers can issue challenges, signaling by tapping a hand on a helmet or cap. Dugout assistance isn’t allowed. A challenge must be made within two seconds, and the pitch graphic with the strike zone is shown on the scoreboard and broadcast. The umpire then announces the updated count.
Schaeffer, who helmed Albuquerque when ABS debuted in Triple-A in 2022, stresses the importance of a unified team strategy for using challenges. “Fifteen people will have fifteen opinions about its use,” he said, “but the key is that everyone is aligned.” He also noted that teams need ongoing, private discussions to place players in the best position to succeed.
Many managers and general managers suggested catchers will typically have the most leeway to challenge, given their line of sight.
Arizona Diamondbacks manager Torey Lovullo added that teams may keep a late-game challenge in reserve for critical moments. “If it’s 0-0 early in the first, I don’t want to risk a wrong call,” he explained. “We’ll start with the catchers, since pitchers can get emotional too. We’ll rely on catchers first, then look for opportunities to challenge later.”
ABS could especially benefit players with elite zone control, like New York Yankees star Aaron Judge, who led the AL with 124 walks last season. Yankees manager Aaron Boone said, “Players who master the zone should gain from ABS, and Aaron is one of those guys.”
ABS trials occurred in 13 spring-training venues last year, with teams winning 52.2% of 1,182 challenges, averaging about 13.8 seconds per challenge. Strike zones are adjusted to a batter’s height, roughly 53.5% of the batter’s height at the top and 27% at the bottom.
During spring training, hitters’ strike zones are measured on a rolling basis from 10 a.m. to noon, with data checked by the Southwest Research Institute to ensure consistency.
Overall, MLB appears to view ABS as a positive development. Texas Rangers president of baseball operations Chris Young, who previously worked closely with MLB umpires, remarked that they’ve earned support. “Umpiring is tougher than ever, but technology can help bring consistency to the game,” he said.
AP Baseball Writer Ronald Blum contributed to this report, providing context for the broader baseball community.
