MLB's Automated Ball-Strike challenge system is again part of spring training, but unlike last year, it will remain once the regular season starts. It's about to profoundly change baseball. K.C.

A scoreboard shows an ABS challenge in spring training. MLB is comfortable with the system's margin of error. But not all players or umpires are quite as comfortable ...

Phillies catcher J.T. Realmuto has another task added to his to-do list before every game this year. In addition to his normal scouting reports on each opposing hitter that he uses to devise a game ...

Major League Baseball umpires are being forced to adjust to a new world behind home plate, where players can challenge their called balls and strikes with a robot checking their work.