MLB ABS Stats for Umpires with Highest Overturn Rate Revealed from Opening Week

Just five days into the 2026 MLB season, it's clear that the new Automated Ball-Strike challenge system is already paying dividends.

The Athletic's Johnny Flores Jr. provided a list of umpires with the highest overturn percentage among those who faced two challenges or more since Opening Day last week, with Chad Whitson leading the way with seven challenges that were overturned.

• Chad Whitson: 7/7 (100 percent)
• C.B. Bucknor: 6/8 (75 percent)
• Chris Segal: 7/10 (70 percent)
• Tripp Gibson: 4/6 (66.7 percent)
• Carlos Torres: 4/7 (57.1 percent)

MLB posted additional stats:

Whitson worked the series finale between the New York Yankees and San Francisco Giants and had a rough day. The Yankees had three calls overturned in their 3-1 win, while the Giants were responsible for the other four.

Meanwhile, Bucknor found himself at the center of attention during Saturday's game between the Boston Red Sox and Cincinnati Reds, with Eugenio Suarez's back-to-back challenges going viral.

Unsurprisingly, multiple catchers across MLB found success with the new challenge system. Kansas City Royals star Salvador Perez had all four of his challenges overturned, while J.T. Realmuto of the Philadelphia Phillies and Austin Wells of the Yankees were successful on all three of their challenges.

In all, 10 players with two or more challenges entered Monday with a 100 percent success rate, and seven of them were catchers. Atlanta Braves outfielder Ronald Acuna Jr. and Milwaukee Brewers catcher William Contreras both lost their two challenges, making them the only players with a zero percent success rate.

Thanks to Perez's impressive eyes, the Royals lead the majors with 4-of-4 challenges overturned, while the Arizona Diamondbacks had all three of their challenges reversed. Conversely, the Houston Astros failed to get a call in their favor on all six of their challenges, and the St. Louis Cardinals also failed to win any of their three challenges.

It will be interesting to see how the ABS affects games later in the year when there's a lot on the line, but for now, it appears that teams and players are adjusting nicely to the new system.