Only the batter, pitcher or catcher can challenge an umpire’s ball or strike call with the ABS system. (GeekWire Photo / Kurt Schlosser)Human umpires will remain behind the plate calling balls and strikes in Major League Baseball games, but in 2026 their calls will be officially open to challenge via technology for the first time. The league’s Joint Competition Committee voted Tuesday to bring the Automated Ball-Strike (ABS) Challenge System to the big leagues next season, following several years of experimentation in the Minor Leagues and use in MLB Spring Training and the All-Star Game this year. Baseball traditionalists and champions of change offered opinions about how technology could alter the sport for better or worse. MLB.com has a lengthy FAQ on the rules around the ABS Challenge System, including how many challenges a team gets, how it all works and more.