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A called strike in a 2026 Major League Baseball game is two decisions stacked on top of each other. The home-plate umpire calls the pitch. If the batter, the pitcher, or the catcher challenges that call, a tracking system checks the pitch against a measured box. The box is not a drawing of the batterâs shoulders. It is a rectangle set from the playerâs measured height, placed at the middle of home plate.
That split is the whole thing to watch. The broadcast graphic is not a second opinion about the swing. It is a check of one called ball or strike, and only after someone on the field spends a challenge.
I follow games on the official broadcast, not from the dugout. The useful habit is to read the graphic the league puts on the screen, then ignore the argument in the booth until the graphic is done.
The umpire still calls every pitch
The Automated Ball-Strike Challenge System did not take the plate away from the umpire. Major League Baseball announced on September 23, 2025, that the system would be used in all Spring Training, championship-season, and postseason games beginning in 2026. Umpires still call every pitch. A challenge is an appeal of that call.
Only three people can make it: the pitcher, the catcher, or the batter. A manager cannot. A coach cannot. Another player cannot. The request has to come immediately after the call, and the player cannot take help from the staff or from anyone else. The league said the process takes about 15 seconds. The umpire announces the challenge in the ballpark. A graphic shows the result on the scoreboard and on the broadcast.
Each club starts the game with two challenges. A successful challenge is retained. A wrong challenge is spent. In each extra inning, a team that has none left is given one for that inning. MLBâs Statcast site also notes that challenges are not permitted when a position player is pitching.
If nobody challenges, the umpireâs call stands. A pitch can be outside the measured box and still be a called strike for the rest of the at-bat. The system is not reviewing the game in the background.
The box is a percentage of height, not a stance
The challenge zone is a two-dimensional rectangle at the middle of home plate. The width is the width of the plate, 17 inches. The top is 53.5 percent of the batterâs measured height. The bottom is 27 percent of that height. Players are measured standing, without cleats, in a standardized check. MLB certifies the height before the player can appear in a Major League game.
A pitch is a strike on a challenge if any part of the ball touches any part of that rectangle. The ball does not have to be buried in the middle. A clip of the ball on the edge counts.
The plane is the middle of the plate, not the front edge and not the back point. A sweeper that nicks the front of the plate and then dives off the other side is judged where it crosses the middle. That choice was deliberate. Testing a three-dimensional zone over the whole plate, and testing a plane at the front, both produced more strikes than the league wanted.
This is why a crouch does not move the box. The old written description of the strike zone talks about the batterâs stance as he prepares to swing: a line at the midpoint between the top of the shoulders and the top of the uniform pants, and a line at the hollow beneath the kneecap. The 2026 challenge zone does not use that description. It uses the certified standing height. A batter who bends deep does not pull the top of the ABS box down to his shoulders. A batter who stands tall does not push it up.
That gap is the argument you hear. Announcers still talk about âthe lettersâ and âthe knees.â The challenge graphic is talking about 53.5 and 27. Both can be on the screen at once. They are not the same ruler.
What to look at when the graphic appears
Wait for the box, not for the first shout. The graphic is drawn for that batter. Aaron Judgeâs box and Jose Altuveâs box are not the same height, because the percentages are applied to different measured heights. A pitch at the top of one batterâs box can be a ball to a shorter batter. Comparing two at-bats by eye, without the graphic, is how the argument starts.
Then look at which part of the ball is touching the line. The rule used for the challenge is any part of the ball on any part of the zone. A pitch that looks off the plate on a freeze-frame can still be a strike if the ballâs edge reaches the rectangle. The opposite is also true. A pitch over the middle of the broadcast camera is not automatically a strike if, at the middle of the plate, the ball has already sunk below 27 percent of that batterâs height.
Then look at who tapped for it. If the catcher challenges a ball, the club is saying the pitch caught the box. If the batter challenges a strike, he is saying it missed. The dugout pointing does not count. If the next pitch is thrown before anyone on the field has challenged, that call is finished.
A retained challenge is not a free look at the next close pitch. It is the same chip, still in the clubâs pocket, because the last one was right. Clubs that are wrong twice are done until an extra inning gives them one back. Saving both for the ninth is a strategy. Spending one in the first on a pitch four inches off is also a strategy. The graphic does not tell you which was wiser. It only tells you whether the call matched the box.
What the graphic does not settle
It does not grade a swing. A batter who offers at a pitch has swung. The challenge system is for a called ball or strike. Foul tips, swings and misses, and balls put in play are not waiting on the rectangle.
It does not apply itself. No challenge, no review. A blown call that nobody appeals is the call.
It does not travel to every league. Nippon Professional Baseball, college baseball, and high school baseball are not this system. A rule you learned in another league is not a correction of an MLB graphic. If you are watching a non-MLB game, use that leagueâs rulebook.
It does not replace the printed definition by itself. The longstanding Official Baseball Rules text still describes the zone from the stance, the shoulders, the pants, and the hollow beneath the kneecap. The challenge zone used in 2026 games is the measured rectangle in MLBâs ABS announcement: 17 inches wide, 53.5 percent up, 27 percent down, judged at the middle of the plate. When those two wordings diverge, the broadcast graphic for a challenge is using the measured one. Check the current Official Baseball Rules PDF before you treat either wording as the only sentence in the book. Rules get revised. The September 23, 2025, release is the leagueâs own description of the system it put on the field in 2026.
It is also not a scouting report. A pitcherâs command is not âgoodâ because three challenges went his way. Three challenges are a sample of three pitches. The box can confirm the call and still say nothing about the rest of the start.
A way to watch one at-bat
Pick the batter, not the star. When he steps in, the graphic you will get later belongs to his certified height. If a called strike is challenged, look for three marks: the 17-inch width, the top at 53.5 percent, the bottom at 27 percent, all at the middle of the plate. If any part of the ball touches that rectangle, the challenge should come back a strike. If it does not, the call should flip.
Then watch the next pitch as a human call again. The umpire is back on the hook until someone spends another challenge. That reset is the part the booth often skips. The box was a review. It was not a new umpire.
Sources
- MLB press release, September 23, 2025, ABS Challenge System for 2026: who may challenge, two challenges retained if successful, extra-inning challenge, 17-inch width, 53.5 percent top, 27 percent bottom, middle of the plate, any part of the ball. https://www.mlb.com/press-release/press-release-mlb-announces-abs-challenge-system-coming-to-the-major-leagues-beginning-in-the-2026-season
- Baseball Savant ABS dashboard: measured height without cleats, zone at the middle of the plate, no challenge when a position player is pitching. https://baseballsavant.mlb.com/abs
- MLB strike-zone history, including the older written definition used before the challenge zone. https://www.mlb.com/official-information/umpires/strike-zone
- Current Official Baseball Rules PDF, for the printed definition and any later revision. https://www.mlb.com/official-information/official-rules
