A call is overturned to a walk by the Automated Ball-Strike (ABS) Challenge System, displayed on the stadium screens, after Cincinnati Reds' Will Benson challenged at pitch result during the seventh inning of a baseball game against the Boston Red Sox in Cincinnati, Saturday, March 28, 2026. (AP Photo/Carolyn Kaster)

Salvador Perez and the Kansas City Royals have been baseball’s best at utilizing their robot challenges through the first weekend of the Automated Ball-Strike System.

Perez topped all catchers by going 4-0 on challenges, while San Francisco’s Heliot Ramos and Cincinnati’s Eugenio Suárez were the only batters who went 2-0 — Suárez won his appeals on consecutive pitches.

“I don’t know if I like it or not,” Perez said. “I don’t want the umpire to look bad.”

Three-time MVP Mike Trout of the Los Angeles Angels is 3-1 on challenges.

Atlanta’s Ronald Acuña Jr. was the only batter who went 0-2.

Kansas City and Arizona were the only perfect teams, with the Royals 4-0 and Arizona 3-0. Houston was 0-6 and St. Louis was 0-3.

Many teams have tried to save their challenges for high-leverage situations.

“1-1 counts. Counts that are going to end the at-bat. Those are big challenge times,” said Phillies manager Rob Thomson, whose team went 4-3.

Challenges had a 53.7% success rate through 47 games. There were 175 challenges, an average of 3.7 per game.

Catchers succeeded on 59 of 92 challenges for a 64% rate, but batters on 33 of 78 for a 42% rate. There were just five challenges by pitchers, with Baltimore’s Ryan Helsley and the Athletics’ Hogan Harris winning, and the Los Angeles Dodgers’ Edwin Díaz, Houston’s Roddery Muñoz and Philadelphia’s Zach Pop losing.

Cincinnati batters went 6-0, while Braves batters were 0-4.

“We have guidelines that we think are strategic and give us a good idea of when we want to challenge,” said Chicago White Sox manager Will Venable, whose team is 4 for 9. “A mid-at-bat challenge is different than a potential strikeout or walk.

C.B. Bucknor had the poorest ABS results among umpires when six of eight challenges of his calls were successful during Cincinnati’s 6-5, 11-inning win on Saturday. All six overturned calls involved strikes being changed to balls. The two confirmed calls involved a ball and a strike.

Boston’s Alex Cora was ejected in that game by Bucknor for arguing a checked swing call.

“I feel bad for them because everybody has a bad day,” Thomson said of the umpires. “The last thing you want to see is somebody get embarrassed. I don’t care who it is, player, coach, umpire. I don’t want to ever see anybody get embarrassed playing this game.”

Minnesota’s Derek Shelton became the first manager ejected for arguing an ABS call on Sunday. He was tossed in the ninth inning of a game against Baltimore after complaining that Helsley waited too long to signal for a review.

Under the ABS system that started this season, teams can appeal strike zone decisions to a system based on 12 Hawk-Eye cameras that measure whether any part of the ball crosses the strike zone with accuracy of about one-sixth of an inch.

“I kind of believe there’s going to be a change with the percentage of the ball that’s touching,” Milwaukee manager Pat Murphy said. “When the ball just nicks it, should that be a strike?”

YANKEES LOSE GAME, BUT WIN CHALLENGES

SEATTLE — The New York Yankees won all five of their challenges utilizing the Automated Ball-Strike System during Monday night’s 2-1 loss to the Seattle Mariners.

While manager Aaron Boone would have liked for his team to stay undefeated four games into the season, he was pleased with the keen eyes many of his hitters displayed against Mariners starter Luis Castillo, who tossed six scoreless innings.

“Really good job by the guys,” Boone said. “When you have that kind of success rate, it’s not going to be like that every night. But, I thought every one was obviously warranted, and a couple in some key spots to give us a chance to build an inning. We just weren’t able to build much offensively tonight.”

It started in the bottom of the second when José Caballero correctly challenged that two called strikes by plate umpire Mike Estabrook were balls, including a 3-2 pitch from Castillo. Caballero tapped his helmet to ask for a challenge as he took his left shin guard off.

Giancarlo Stanton also successfully challenged that a 1-2 slider by Castillo was below the strike zone, and then reached on a single. One batter later, Jazz Chisholm Jr. challenged that a first-pitch slider by Castillo was out of the zone, though he later struck out.

After that at-bat, Estabrook and Boone had a verbal exchange, with Boone remaining in the dugout.

“Those are razor-thin pitches sometimes,” Boone said. “You don’t want to always have to be challenging. But good on the guys for just hammering the strike zone right now.”

New York is 10 for 11 on ABS challenges this season.