Beginning Thursday, the automated ball and strike system will allow players to challenge umpires’ calls. If all goes well, the system could debut in regular season games as soon as next year.

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.