99% Invisible 99% Invisible

RoboUmp Hits the Big Leagues

Apr 14, 2026

Summary

This 99% Invisible episode explores Major League Baseball’s introduction of the Automated Ball-Strike (ABS) system, a robot umpire technology. Host Roman Mars and producer Chris Berube discuss the shift from full automation to a challenge system, where players can contest calls. They examine the trade-offs between accuracy and the human elements of the game, highlighting how the new rule impacts umpire reputation and fan engagement.

Topics discussed

Intro and Capital One Saver Card ad MLB rule changes and the new challenge system The LeVon Hernandez 15-strikeout game Human umpire accuracy and fallibility History of robot umpires and ABS technology Tracking tech in other sports and MLB stadiums Testing ABS in the minor leagues The 'compassionate umpire' and human nuance Umpire abuse and the calming effect of robots Conclusion on robot umpire adoption Ads for Article, Squarespace, and Walmart Update: How the challenge system works in MLB Impact on game flow and fan engagement The C.B. Buckner viral challenge incident Outro and final ads
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