Robot Umpires Overturned 54 Percent of Challenged Calls in Their First MLB Season
Trill News Briefing
The Story
MLB robot umpires overturned 54 percent of challenged calls in the first season of the Automated Ball Strike challenge system, and catchers did the best job.
Teams made 10,557 challenges, about 4.35 per game, and won 5,686 of them, according to the Associated Press.
Catchers succeeded 59 percent of the time, batters 49 percent and pitchers just 40 percent, and Philadelphia's J.T. Realmuto led frequent challengers among catchers at 81 percent.
Cincinnati gained a net 16.8 runs from overturns by Baseball Savant's measure, while Cleveland lost 13.4.
Because two wrong appeals cost a team its right to challenge, clubs saved them, and the ninth inning drew more challenges than any other but won just 40 percent of the time, against 61 percent in the first three innings.
Teams grew bolder as they learned, rising from 3.76 challenges per game in March to 4.61 in September.
Umpire Andy Fletcher was overturned on 66.1 percent of challenged calls and Jansen Visconti on 42.2 percent, and Realmuto says umpires bristle when a call flips by less than a tenth of an inch.
Teams made 10,557 challenges, about 4.35 per game, and won 5,686 of them, according to the Associated Press.
Catchers succeeded 59 percent of the time, batters 49 percent and pitchers just 40 percent, and Philadelphia's J.T. Realmuto led frequent challengers among catchers at 81 percent.
Cincinnati gained a net 16.8 runs from overturns by Baseball Savant's measure, while Cleveland lost 13.4.
Because two wrong appeals cost a team its right to challenge, clubs saved them, and the ninth inning drew more challenges than any other but won just 40 percent of the time, against 61 percent in the first three innings.
Teams grew bolder as they learned, rising from 3.76 challenges per game in March to 4.61 in September.
Umpire Andy Fletcher was overturned on 66.1 percent of challenged calls and Jansen Visconti on 42.2 percent, and Realmuto says umpires bristle when a call flips by less than a tenth of an inch.
Why It Matters
The overturn rate is not an overall error rate: players select which calls to contest, and the unchallenged calls are outside this count. That distinction matters when judging either umpires or the technology. In a 2022 account of their research in The Conversation, organizational scientists reported that incorrect calls in 2008 to 2014 MLB playoff data were followed more often by calls favoring the wronged team. That older study did not evaluate the 2026 challenge system. Watch whether future seasons report accuracy for all pitches alongside selected challenges, making the system easier to judge beyond its overturn rate.
Go Deeper
Read the original reporting at Associated Press via KIRO 7.
Read Full Story at Associated Press via KIRO 7 →