RoboUmp Hits the Big Leagues

Major League Baseball has introduced several rule changes in recent years, including a pitch clock and stricter rules on foreign substances. However, the most talked-about change for the 2026 season is the introduction of robot umpires, specifically the ABS (Automatic Balls and Strikes) system. This system will allow players to appeal a ball or strike call, with the robot arbitrator having the final say. The idea of robot umpires isn't new; the Brooklyn Dodgers tested a rudimentary machine in the 1950s that proved ineffective. Modern "robot umpires" are not physical robots but sophisticated camera-based tracking systems, similar to those used in tennis (Hawkeye) and soccer for offsides and goal-line technology. Most MLB stadiums already have advanced ball-tracking systems, initially installed for TV broadcasts, which can track every revolution of a baseball and its exit velocity. This technology allows viewers to see the precise location of pitches within the strike zone, often leading to frustration when human umpires make calls that contradict the visual evidence. The push for robot umpires stems from the inherent fallibility of human umpires. Despite getting calls right 94-97% of the time, a 2018 study found that umpires make about 14 incorrect calls per game, totaling 34,000 bad calls annually. These errors can significantly impact game outcomes, even deciding championships, as seen in the 1997 playoffs where pitcher LeVon Hernandez benefited from an unusually wide strike zone called by umpire Eric Gregg. While human umpires are improving, the high speed of baseball pitches makes perfect accuracy incredibly difficult. Major League Baseball has been testing the ABS system in the minor leagues since 2019 to refine the technology and acclimate fans. Initially, the ABS system was programmed to call a "textbook" strike zone, but this led to complaints from players and fans who felt it called too many hittable pitches as balls. Consequently, the system was reprogrammed to expand the strike zone slightly, better reflecting what human umpires typically call. One of the main arguments against robot umpires is the loss of "charm and drama" and the human element in baseball. Human umpires instinctively adjust the strike zone based on game context, such as a struggling pitcher or a lopsided score, a phenomenon known as the "compassionate umpire effect." These subtle, often unconscious, adjustments contribute to the romanticized imperfections of the game. Furthermore, yelling at umpires is a deeply ingrained part of baseball culture, providing a cathartic outlet for fans and players. However, the abuse directed at umpires can be severe, ranging from constant heckling to death threats and physical assault. Former umpire Fred DeJesus, who was one of the first to use the ABS system, noted that it was highly accurate. The hope was that robot umpires would reduce this vitriol by removing the human element from controversial calls, making fans see umpires as people rather than targets of anger. In 2024, the robot umpire system officially arrived in Major League Baseball, but not in the fully automated way initially predicted. Instead of the ABS system making all calls, MLB implemented a challenge system. Human umpires continue to make all ball and strike calls, but players can challenge a call. If a challenge is made, the ABS system quickly reviews the pitch and determines if the original call was correct. Each team is allotted two challenges per game, and a successful challenge allows the team to retain that challenge. This incentivizes strategic use of challenges, typically on critical plays or when players are confident in their appeal. This challenge system has been surprisingly well-received by fans, adding a new layer of drama to the game. When a player challenges a call, everyone in the stadium looks to the scoreboard for the ABS system's verdict, and fans cheer when their team's challenge is successful. This creates a dynamic where the robot acts as an impartial arbitrator in disputes between players and umpires, rather than replacing the human element entirely. However, for umpires, the system presents a different challenge. Retired umpires have expressed sympathy for active MLB umpires, as the challenge system frequently highlights their mistakes on a giant scoreboard for thousands to see. This can be detrimental to an umpire's self-esteem and reputation. An example is umpire C.B. Buckner, who became widely known after several of his calls were overturned in a single game, leading to widespread criticism and online ridicule. This outcome is somewhat contrary to the initial hope that robot umpires would reduce hostility towards human officials, as it instead puts their judgment under an even greater microscope. Despite these challenges, the robot umpire system, in its current challenge-based form, is expected to remain a part of Major League Baseball, evolving as the season progresses.