For the first time in history, the Automated Ball-Strike (ABS) Challenge System is being used in MLB this season.
The ABS challenge system allows each team to have two challenges regarding balls/strikes calls per game, plus potential additional challenges in extra innings. To challenge a ball/strike call, a player has to tap his cap or helmet to let the umpire know he wants to challenge the call.
If a team wins a challenge, they get to keep it. Essentially, teams have unlimited challenges until they get two wrong.
It's been interesting to see how teams utilize their challenges. The Twins have been the most aggressive team in using the system, leading the league with 22 overturns. The Miami Marlins have the second-most overturns with 17.
While the Twins have collectively been great at using the ABS challenge system, one player stands out for his ability to successfully challenge: catcher Ryan Jeffers.
Twins catcher Ryan Jeffers is thriving with ABS challenge system
Two more successful ABS challenges for catcher Ryan Jeffers and both were inning-ending strikeouts.
— Aaron Gleeman (@AaronGleeman) April 8, 2026
Jeffers is tied for the MLB lead with 10 challenges won.
Derek Shelton praised Jeffers' eye and feel for situational leverage: "I'd be shocked if there's anybody better at it."
Regarding ABS challenges, Jeffers has gone 2-for-2 as a hitter and 8-for-13 behind the plate. Jeffers leads all MLB catchers by turning six called balls into strikeouts.
Two of Jeffers' successful defensive challenges occurred during the Twins' 4-2 win against the Tigers at Target Field last night. Jeffers overturned a splitter from Taj Bradley to end the sixth inning, and he overturned a sweeper from Taylor Rogers to end the seventh inning.
Before the season began, it appeared Jeffers would be one of the players who'd benefit the most from the ABS challenge system. Jeffers has one framing run (73rd percentile) in the pandemic-shortened 2020 season, six framing runs (88th percentile) in 2021 and four framing runs (73rd percentile) in 2022. However, the Twins catcher posted a combined -14 framing runs from 2023 through 2025. Since Jeffers apparently got worse at framing, it seemed obvious he could use the new system to overturn calls he failed to frame adequately.
Jeffers ranks in the 62nd percentile in framing runs (0) this season, which is significantly better than his numbers from the last two seasons. Therefore, while he is benefiting from ABS, it's not because of poor framing numbers. His improved framing stats and his elite ability to win challenges make him extremely valuable behind the plate.
While Jeffers has undoubtedly helped the Twins win games using ABS challenges, outfielder Matt Wallner has hurt the Twins with his use of the system.
Twins outfielder Matt Wallner is struggling with ABS challenge system
After unsuccessfully challenging a first-pitch sinker from Tigers lefty Tarik Skubal on Tuesday, Wallner is 1-for-4 with his challenges this season.
He's 1-4, which is the same number of challenges the Diamondback hitters have made all season so far. https://t.co/EfqqdiJQ0f
— Declan Goff (@DexsTweets) April 8, 2026
Perhaps manager Derek Shelton should tell Wallner to refrain from challenging unless it's in the late innings. Wallner may be good at hitting homers (three this year), but it appears he isn't great at challenging. Even with Wallner's poor challenge stats this year, the Twins should overall be content with how they've been utilizing the ABS system.