Phillies batters still getting the hang of ABS challenges, finding them to be a game of inches

One series into the 2026 season, the Phillies are seeing firsthand just how slim the margins can be for automated ball-strike challenges.

In the 10th inning of the Phillies’ loss to the Rangers on Saturday, Kyle Schwarber initiated a challenge of a called strike from Tyler Alexander. The ABS display on the board confirmed that the pitch had just caught the bottom outside corner of the zone, just 1.1 inch over the edge, and the Phillies lost their final challenge. For reference, the diameter of a regulation baseball must be between 2.86 inches and 2.94 inches.

“You see all those really close pitches where the ball’s just nicking the line, or were just nicking the upper corner, one way or the other, which typically have been balls, and now they’re strikes,” manager Rob Thomson said. “So it’s hard. It’s very hard.”

Even though the challenge didn’t work out and Schwarber was ultimately called out on strikes in that at-bat, that was exactly the situation in which Thomson wants his hitters to challenge aggressively. The Phillies were down one run at the time, and if the pitch had been overturned, it would have flipped the count to 3-1.

If the Phillies are trailing late in the game, Thomson prefers to save challenges for hitters. If they’re leading late, challenges are prioritized for pitchers and catchers.

“It’s counts that are going to change the at-bat, 1-1 counts, counts that are going to end the at-bat. Those are big challenge times,” Thomson said.

He added that at this point, none of his hitters has a red light for challenges.

It’s a learning process. In the eighth inning Sunday, Schwarber successfully challenged a pitch from Carter Baumler that was initially called a strike but turned out to be 1.6 inches outside the zone. What would have been an 0-2 count was flipped to 1-1, although Schwarber ultimately flied out later in the at-bat.

» READ MORE: Phillies are batting .186 after second straight loss to the Rangers

On the defensive side, the Phillies are already seeing the benefit of a veteran catcher in J.T. Realmuto, who has continued his perfect streak of challenges in spring training and is 3-for-3 in the regular season. On Sunday, he successfully challenged the call on a fastball from Jesús Luzardo that caught the plate by 0.7 of an inch.

“He’s caught a lot of pitches in his career, so he knows the zone and he did a great job in spring training,” Thomson said. “So I think the pitchers, for the most part, try to keep their emotions in check and let him and [Rafael Marchán] do the challenges.”

Zack Wheeler (thoracic outlet decompression surgery) and Orion Kerkering (hamstring strain) were both back at Citizens Bank Park on Sunday, a day after their first rehab appearances for triple-A Lehigh Valley. Wheeler felt fine after his three innings, and is on pace to make his next minor-league start on Saturday.

Thomson watched the tape of their outings, as the triple-A game had been at the same time as the Phillies’ extra-innings loss to the Rangers on Saturday.

“[Wheeler] was really good,” Thomson said. “Breaking ball was good, fastball keeps creeping up in velocity. ... And Kerkering was really good, too.”

Thomson was particularly impressed by Kerkering’s new splitter, which he flashed twice in his Saturday outing. He has been developing the pitch over the offseason and spring, and Thomson said it had good bottom to it.

“It’ll be a good pitch for him,” he said.

Realmuto will get a day off Monday against the Washington Nationals, with Marchán scheduled to start behind the plate. Thomson wanted to ensure Realmuto lined up to catch Andrew Painter’s debut on Tuesday. ... Taijuan Walker is scheduled to start the series opener (6:40 p.m., NBCSP+) against Nationals lefty Foster Griffin.