MLB expands experimental partnership with independent Atlantic League

Major League Baseball announced Wednesday it has expanded its partnership with the independent Atlantic League of Professional Baseball.

MLB and ALPB partnered in 2019 to serve as a testing ground for experimental rules like the Automated Ball-Strike System, which helps umpires call balls and strikes more accurately. In addition to robo umps, the independent league also tested rules limiting defensive shifts, mound visits, shortening inning breaks, and the use of larger bases.

That agreement has been extended through the 2023 season, so ALPB will continue to test potential rule changes for at least the next several seasons.

So far, MLB has not committed to using the automated umpire system at the big-league level.