Baseball is a pastime laced with tradition, but it can also be an ambiguous sport. Did a pitcher throw strike three, or did it just miss the corner of the zone? So far, that decision has hinged on the umpire behind the plate. To improve this murkiness, Major League Baseball (MLB) is testing automated systems for calling balls and strikes—first in the minor leagues, then major league spring training, and most recently during the 2025 All-Star Game, powered by T-Mobile 5G tech.
Although the league could let computers determine every pitch, it’s not going down that path yet. Instead, it’s using a hybrid Automated Ball-Strike (ABS) challenge system, which lets certain players request a review of the computer’s verdict. And despite being a technology journalist, enthusiastic about screens and gadgets, I think the human-computer mix is the right choice.
How the ABS Challenge System Works
(Credit: MLB)
With ABS, both teams get two challenges. The pitcher, catcher, and batter are the only ones who can invoke it immediately after a call. An advanced camera system checks each pitch. If one is challenged, then its precise location on the strike zone is shown to viewers, confirming or overturning the call. If a player is wrong, their team loses a challenge. If they’re right, they retain it.
“The call of a pitch impacts teams not just during the game, but also for future games because there are so many pitching decisions that have to be made as a result of pitch counts going up,” says Randy Wilkins, filmmaker and director of ESPN’s Derek Jeter docuseries The Captain. “So I think it’s a very important element to add to the game. If pitching and hitting are improving, then the officiating of the game should catch up with that as well. And I think ABS is a big part of that.”
MLB insider Jeff Passan is another “robot ump” advocate. But as I’ve casually talked to people over time, the issue of computers calling balls and strikes is still controversial. The people against it usually start by asking, “What about the human element?”
The Human Element Doesn’t Conflict With Technology
UmpScorecards2200 (Credit: UmpScorecards)
As of August 2025, the top 10 umpires behind the plate have an accuracy rate between 95% and 96%. That’s commendable for people who’ve called between 2,200 and 3,400 pitches this year, but even the most generous interpretation means 88 missed calls per umpire.
Like MLB’s Instant Replay, ABS challenges are not about dictating a game; they’re a safety net that improves game accuracy. Had it been in place 15 years ago, when umpire Jim Joyce made one of the biggest mistakes of all time, there would be 25 perfect games in baseball history, not 24.
The human element is a manager knowing their pitcher’s personality, and choosing them in a high-pressure situation, not swapping in a different pitcher because an analytics sheet tells them it’s the “right” choice. It shouldn’t be millions of people watching a critical game on TV clearly seeing the umpire miss a perfect pitch painting the corner of the strike zone.
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The Challenge System Is an Unspoken Contract
I enjoyed seeing ABS in action during spring training, but it wasn’t until MLB used it during the All-Star Game that I understood why I like the challenge system. The technologist in me tends to favor more automation, but the hybrid system on display in the Midsummer Classic demonstrated how technology could be poetically laced into the sport.
To me, the ABS challenge system looks like an unspoken contract between the only three people on the field who matter in the moment: the pitcher, catcher, and batter. With every pitch, each of them silently agrees that they’re satisfied with the umpire’s call as play moves on.
If someone disagrees but doesn’t call a challenge, they’re signaling that the call isn’t egregious enough, or the timing of the call isn’t important enough, to disrupt the flow of the game.
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I like that delicate, symbiotic balance. It has the feel of backyard baseball, just three guys playing ball, with an escape valve to keep things in check— as long as they use it.
“The only thing for me is to have more than two challenges,” says Wilkins. “I think only having two challenges is low because of the frequency of pitches. There are just so many pitches in a game that two seems a little too low.”
Baseball Is Already a Technology-Infused Game
(Credit: Tyler Hayes)
Baseball is always evolving, and once it changes, good luck going back. Imagine removing PitchCom, Instant Replay, or StatCast.
Nearly every broadcast now includes an on-screen strike zone, so every viewer is already seeing balls and strikes being verified in some form. With ABS, the players will use challenges to show the fans which calls and moments are truly important.
It shouldn’t take a catastrophic moment, like a blown perfect game, to spur adoption of new technology. It should be included as soon as it’s ready. The MLB’s Joint Competition Committee will reportedly soon consider whether or not to use it in the 2026 season. I think it would be negligent to exclude it.
About Tyler Hayes
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