Robot umpires are coming to MLB. Here's how they work

NEW YORK (AP) — Robot umpires are officially arriving in the big leagues this year. This transformation represents one of the most significant technological shifts in the history of professional baseball, aiming to enhance precision and accountability at home plate. Major League Baseball is embracing this transition through a calculated, phased approach, prioritizing fairness while preserving the traditional feel of the game by keeping human arbiters at the center of every play. This evolution marks the culmination of years of rigorous testing and data gathering across minor league levels.

The Automated Ball/Strike System (ABS) will be implemented as a specialized challenge system. In this format, a human umpire retains authority for every call made on the field, ensuring the game maintains its established flow. However, players gain the power to appeal questionable calls directly to the computer’s high-tech diagnostic systems. Robot umpires have undergone extensive validation in the minor leagues since 2019, with recent iterations deployed in Triple-A play, various spring training environments, and the spotlight of the 2025 All-Star Game in Atlanta, signaling that the system is ready for the professional stage.