MLB introduced the Automated Ball-Strike (ABS) Challenge System powered by T-Mobile beginning with the 2026 season. Only batters and pitchers/catchers may initiate a challenge.
Each team starts with two challenges; teams will lose the ability to challenge after they do so incorrectly twice. The ABS zone is set as follows:
the top is 53.5% of a player's measured height without cleats, the bottom is 27%, and pitch location is captured above the middle
of the plate, not the front.
This page shows Statcast's advanced ABS metrics. For an at-a-glance dashboard, go here.
How to read these metrics:
Runs Above Average is a measure of how much added run value that player has contributed with his challenge performance. It combines both the run value of successful challenges ("gained")
compared to the expected gain on identical pitches, and the run value of unsuccessful challenges ("cost") compared to the expected cost on identical pitches. Runs Gained accounts for
only successful challenges, while Runs Cost accounts for only unsuccessful challenges.
% Runs/Overturns Taken is a measure of how often a player is actually taking advantage of his challenge opportunities. Possible Runs/Challenges accounts for every challenge
opportunity available to that player (an incorrect call going against that player when his team has remaining challenges). A higher % Runs/Overturns Taken indicates the player is actually using more
of those opportunities, while a lower percentage means he is more passive with those opportunities. Runs/Overturns Not Taken shows how many runs/overturns of unrealized value the player left on the table.
Example: Best among MLB catchers during the 2026 regular season, Jonah Heim added 4.3 runs of ABS challenge value compared to expected. He gained 4.2 more runs than expected on successful
challenges (14.2 runs gained vs. 10.0 expected runs gained) and cost roughly 0.1 runs less than expected on unsuccessful challenges (1.19 runs cost vs. 1.24 expected runs cost). He gained 14.2
runs out of a possible 26.8 runs available to him in all challenge opportunities, giving him a 53% runs taken value, well above the catcher average of 40%.
