ABS is MLB’s name for an automated strike zone — also known as robot umps. In a full ABS game, there will be a human umpire behind the plate, signaling the calls communicated through ABS. We won’t be seeing that full system in action this spring. Instead, teams will have a limited amount of challenges.

A computerized system that calls balls and strikes is being tested during Major League Baseball spring training exhibition games starting Thursday after four years of experiments in the minor leagues.