PHILADELPHIA -- If you thought there was no possible way Major League Baseball could squeeze in more opportunities to challenge something with video, think again. There's more on the horizon. It started in the Arizona Fall League and now continues in the minors, where hitters can challenge whether or not they committed to a swing.
In common parlance, it is a check swing or checked swing. The rulebook calls it a "half swing," even though that isn't always accurate. What we're obviously talking about is when a hitter starts a swing but either stops it or attempts to stop it before completing a full swing.
Oddly, the rulebook doesn't define how far a hitter must go in order for it to be determined as a swing. Seriously. Here's the only part of the rulebook that touches on it, Rule 8.02c's comment:
Appeals on a half swing may be made only on the call of ball and when asked to appeal, the home plate umpire must refer to a base umpire for his judgment on the half swing. Should the base umpire call the pitch a strike, the strike call shall prevail. Appeals on a half swing must be made before the next pitch, or any play or attempted play. If the half swing occurs during a play which ends a half-inning, the appeal must be made before all infielders of the defensive team leave fair territory.
The appeals process is clearly outlined, but why is there no definition of what actually constitutes a swing? Regardless, there's technology out there that determines whether or not a player swung the bat. The determination has fallen at 45 degrees. More specifically, "if the bat's barrel is judged to have traveled more than 45 degrees past its final stopping point, then it is judged a swing. If it moves less than 45 degrees, then it's not a swing." Here's what it looks like in action:
If you haven’t seen it before, this is what the checked swing challenges in A-ball look like pic.twitter.com/AjSJangver
— Mitch Rupert (@Mitch_Rupert) April 22, 2026
It seems pretty hitter-friendly, frankly, as the check swing is usually defined by the bat crossing home plate or breaking of the batter's wrists.
It could be coming to the big leagues sooner rather than later, but what do some of this year's All-Stars think? Should a check swing be challengeable? Opinions, from those who had them, varied.
"I don't know where I'm at with that," White Sox center fielder Tristan Peters said.
"Man, I don't know," said Braves first baseman Matt Olson. "I mean, I've seen some of the videos of it and it looks like it probably favors hitters, so sure. I'll take anything."
"I think so," Reds pitcher Chase Burns said. "We've seen it a little bit in the minors and it's just so hard to see with the naked eye. I think in the upcoming years we'll be able to challenge that."
"Sometimes yes," said Braves second baseman Ozzie Albies. "It's hard to see when you're 100 feet away, as fast as it goes when that happens. The game nowadays, everything is challengeable, so we might as well."
Albies wasn't alone in thinking that using the technology we have is totally fine, as long as it works properly.
"It's like going back to the ABS challenge discussion, just making sure the technology is there," said Tigers left fielder Riley Greene. "Either way, I'm OK with it. We need to make sure it's right, though. Some of the ones I've seen, it's almost a full swing and it says no, not a swing."
"I heard it's a little iffy, like you have to really go around," Blue Jays reliever Louis Varland said. "I don't know if it's a true check swing or not. If there's a way that the system could be set up to measure by the smallest degree of a swing or not, I think that would be beneficial."
Then again, aren't there enough challenges?
"I go back and forth," Nationals slugger James Wood said. "Sometimes I feel like I get screwed on the call, but then I've seen times where they've tried to review it in the minors and I've seen people take, like, full swings and they didn't call it a swing. Also, I feel like it's just too many different things to challenge."
The "too many challenges" sentiment was shared by a few others.
"I hope not," Guardians closer Cade Smith said when asked if this should be implemented. "From what I've heard on the trial runs in the minor leagues and fall league, there's been pretty much full swings called no swing. I think baseball is a great game and it's been such a great game for so long and there's value in preserving the purity of that. Fans come to watch a baseball game, not a video game."
We heard similar arguments before replay was added and again before the ABS system was introduced in the league. There have certainly been negatives, but overall, the review system in baseball is working as intended. Whether MLB takes things a step further with the check swing replay remains to be seen.
