About Challenge The Ump

MLB's 2026 ABS Challenge System is the most significant rule change since the designated hitter. For the first time, players can dispute ball-strike calls using Hawk-Eye camera data — and umpires get overruled on the spot.

Every fan watching a game now asks the same thing: does beating the robot umpire actually help you win?

We built Challenge The Ump to answer that with data. Not vibes, not hot takes — actual challenge outcomes correlated with actual results. Updated every day from Baseball Savant.

Box scores track runs, hits, and errors. Baseball Savant has the raw ABS leaderboard. But nobody was connecting challenge performance to standings in a clean, searchable format with proper sample size warnings and an honest take on what the numbers actually mean.

Challenge The Ump fills that gap. It's the kind of site we wanted to exist, so we built it.

Built by Leye Oyelami — software engineer, baseball fan, and builder of things that make data legible.

This is an open-source project. The code, the data, and the methodology are all public. If you find an error, have a suggestion, or want to contribute, the repo is open.