Major League Baseball plans to test the ball-strike challenge system during next year’s Spring Training, commissioner Rob Manfred said this week. Manfred suggested as much on Monday in a conversation with Jack Curry of the YES Network (X link). The commissioner reiterated that this morning in an interview with Chris Russo on SiriusXM’s Mad Dog Sports Radio.
“What I can tell you 100% is we are going to test the challenge system in Major League Spring Training in 2025,” Manfred told Russo. “I think that’s an important step forward.” That isn’t a stepping stone to implementing the system in regular season games by next year. Manfred said in May that he didn’t believe the technology would be sufficiently ironed out to put the automatic strike zone in place for meaningful games by ’25.
The commissioner didn’t reveal a specific timeline for its regular season implementation. He did tell The Dan Patrick Show last week (X link) that he expected to have some form of automated zone in place by the end of his tenure as commissioner, which concludes in the 2028-29 offseason. The date will presumably be dependent on the feedback MLB gets from players, coaches, and umpires. While MLB initially seemed to embrace a fully robotic zone, they’ve pivoted to the challenge system after testing both the challenge and the full ABS in the minors.
The challenge system leaves the human umpire as the default. Each team gets a finite number of challenges to turn to the automatic zone on borderline pitches. Challenges must be called for in real time by the hitter, pitcher or catcher. That’ll leave some missed calls but reduces the likelihood of a blown call on an especially important pitch.
That assuages some concerns about the rule book strike zone not perfectly aligning with the way players expect the game to be called. One common complaint about the automatic zone is its tendency to reward pitchers for clipping the top of the zone with an elevated breaking ball. That’s less likely to be an issue with the challenge system, as pitchers and catchers won’t often dispute pitches they don’t perceive as strikes themselves.
The challenge system also preserves some of the value of a catcher’s framing ability, although it offers a check in high-leverage spots when stealing a strike would be most significant. From a fan perspective, that’s mostly an aesthetic concern. It’s an economic one for some players, as there are plenty of current catchers whose value is driven largely by their receiving skills.
In an unrelated bit of rule experimentation, MLB used the Arizona Fall League as a testing ground for check swings. As Baseball America’s Josh Norris first observed (on X) last week, players were able to use bat tracking technology to challenge a check swing call.
MLB rules don’t spell out a technical definition of a check swing. Subjectivity doesn’t work for a challenge system. Sam Dykstra of MLB.com writes that the league used a 45-degree threshold for the bat angle. In other words, if the bat angle went beyond the opposite field base line, it was deemed a swing. The check swing challenge was only in use during the Fall League. There’s no indication it’s under consideration for testing with MLB players, though it wouldn’t be a surprise if it gets an eventual trial run in minor league regular season games.