Robot umpire

A robot umpire, also sometimes called Robo Ump in tribute of the classic 1987 science fiction film RoboCop, is a mechanical system that calls balls and strikes instead of the home plate umpire. It has been tested out in some independent leagues and in the Arizona Fall League, and in 2021 was introduced to some Low A leagues in Minor League Baseball, with a view to eventually introduce it at all levels of professional baseball if it proves to work fine. In 2022, its use was moved up all the way to AAA as it seemed inevitable that it would be adopted by the major leagues within a short time frame.

Under this system, there is still a home plate umpire, but his role is limited to calling any play at the plate, and making some specific calls, such as foul tips, checked swings, a batter deliberately being hit by the baseball, or a ball crossing the strike zone on a bounce. For all other calls, he simply records the decision made by the system.

Further Reading

• Jimmy Golen (Associated Press): "Robo umps reach Triple-A, but MLB rollout still uncertain", Yahoo! News, May 9, 2023. [1]
• Manny Randhawa: "Automatic strike zone coming to AAA in '22", mlb.com, January 21, 2022. [2]