What is ABS? MLB begins spring training test of automated ball-strike challenge system

Rowan Kavner

MLB Writer

At Yankees camp on Wednesday, Luis Gil threw a pitch to Aaron Judge that tailed just below the zone. Gil disagreed. Believing it caught the bottom of the plate, he put his hand to his cap. The players gazed up toward the video board, which revealed that the pitch did indeed miss by 1.8 inches. Less than 30 seconds later, the at-bat continued.

This was the automated ball-strike challenge system at play.

While NFL fans dream of the day an electronic system that can more accurately determine first downs, MLB is in the process of figuring out its own way to attempt to remove human error on balls and strikes. Robot umpires haven’t arrived at Major League Baseball yet, but a version of an automated strike zone will be tested this spring.

Starting Thursday at Camelback Ranch, where the Dodgers and Cubs will open Cactus League play, the ABS challenge system will begin being implemented. The system will be in place at 13 stadiums and in more than 60% of spring training games across Arizona and Florida. The setup represents a compromise between humans and full ABS, allowing umpires to decide the majority of balls and strikes while affording players the ability to fix the more egregious calls.