11 Things To Know About MLB’s New ABS Challenge System For 2026

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(Photo by Caitlin O’Hara/MLB Photos via Getty Images)

With MLBâ€s competition committee expected to approve the automated ball-strike challenge system on Tuesday, itâ€s a good time to explain both how ABS works and clear up some of its misconceptions. 

BREAKING: Major League Baseball will use the Automated Ball-Strike Challenge System (ABS) during the entire 2026 season

ABS CHALLENGE RULES:

– Each team will get two challenges and can keep them if they’re successful

– Challenges can only be initiated by a pitcher, catcher, or… pic.twitter.com/xHkRIbHrRx

— MLB (@MLB) September 23, 2025

With Baseball America’s staff covering both the minor leagues and the Arizona Fall League, we have seen the ABS system in action for a number of years now. And weâ€ve had numerous conversations with coaches, players and even umpires who have experienced it in action.

In our experience, much like the pitch clock system, the ABS challenge system can best be described as a change that largely fades into the background before long. Itâ€s there, but you can go innings before being reminded that it exists.

Based on our years spent watching ABS games, here are some myths and misconceptions that are worth clearing up.

Dispelling 6 Myths About Automated Ball-Strike Challenges

Myth No. 1: Youâ€ll See A Lot Of Challenges

The number of ABS challenges each team has is quite limited. In Triple-A, it was three per team in 2023 and 2024 before being reduced to two in 2025.

However, that number is perhaps better described as being two incorrect challenges per team. If a team challenges a pitch successfully, they get another challenge. So, if an umpire is having a very bad day, a team could keep challenging pitches as long as they keep challenging successfully.

Of course, that doesnâ€t happen very often. On average, there were 4.2 ABS challenges out of the roughly 290 pitches thrown per Triple-A game in 2025.

Myth No. 2: ABS Challenges Will Make Games Longer

For 2024 and 2025, Triple-A has used an ABS system that is expected to be very similar to the new MLB system. This is a good thing for those fans worried the challenge system will eat into the progress made in shortening the length of games.

Consider that the average Triple-A game time in 2025 was 2:44. In 2023, when there was a hybrid system (full ABS in some games and challenge system in others), the average game time was 2:42. In 2022, the final year before any ABS experimentation in Triple-A, the average game time was 2:43.

In other words, the ABS challenge system hasnâ€t really affected game time in Triple-A.

That’s because the challenge system is designed to be extremely quick. Fans used to lengthy in-game replay delays are likely to be pleasantly surprised by how quickly decisions are made. This is a system in which no one gets to stop and think for a while before deciding whether to challenge. And once a challenge is initiated, itâ€s resolved within seconds. There are no calls back to a main office in New York or referees going under the hood to watch video.

Yes, the process takes about 10-15 seconds per challenge. But it also eliminates some of the arguments that often arose from players and coaches unhappy about pitch calls. With roughly four challenges per game, thatâ€s an extra 40-60 seconds. Any ejections or lengthy arguments that arose from strike zone disputes took much longer than that.

All in all, the time added by the ABS challenge system has proven to be negligible.

Myth No. 3: ABS Challenges Make Catcher Framing Obsolete

If MLB ever adopted a system in which all pitches were called by the automated strike zone, catcher framing would immediately become meaningless. There’s no denying that. It would result in all types of odd adjustments, as a catcherâ€s only real job as a receiver in that scenario would be to keep the ball in front of them and be ready to throw out basestealers. Even blocking the home plate umpireâ€s view in getting ready to throw would be inconsequential (except in the case of foul tips).

But this isnâ€t that.

In the ABS challenge system, more than 98% of pitches will still be called by the home plate umpire. Getting borderline strikes called will continue to have real value, both in the case of forcing the opposing team to use up challenges and in the many more instances in which they will decide not to challenge.

Similarly, a team with poor framing catcher who canâ€t get borderline calls may be forced to use or burn challenges on pitches that are called balls.

Myth No. 4: The ABS Challenge System Will Affect Hitters And Pitchers Equally

Simply put, the challenge system will be tougher for pitchers.

MLB has always been a tougher test than Triple-A, but for pitchers jumping from Double-A to Triple-A, the ABS challenge system has often proven to be a whole new world. Pitches that were getting called strikes regularly in Double-A (and often getting chase swings from hitters) were being spit at for balls in Triple-A.

As one Triple-A pitcher described it, there’s “a mentality shift” when it comes to pitching under the ABS challenge system.

“My first outing in Triple-A, I noticed right away how much more patient hitters were,” the pitcher told Baseball America. “I was throwing pitches just off the plate that normally get swings, and here they were taking them.

“At first, it was frustrating. Iâ€d come into the dugout asking where that pitch was, and sure enough, it was a ball. That made me realize I had to be better. I donâ€t know if it was the jump from Double-A to Triple-A or just the quality of hitters, but you quickly figure out youâ€ve got to go for in-zone whiffs instead of just chases, because these hitters know the zone so well.”

Myth No. 5. Cheating The System Will Be Easy

The speed with which challenges must be implemented is vital to making this system work. Coaches arenâ€t allowed to challenge pitches—only a hitter, pitcher or catcher can call for a challenge. The challenge has to be called for extremely quickly after the ball/strike call is made.

The idea behind this is to ensure that no player receives outside feedback before making a challenge. For example, a batter doesnâ€t get time to step out and think it over or look to the dugout for guidance. When the pitch is called, a player either taps his head or he doesn’t. The window to challenge the pitch closes just as fast as it opened.

On top of that, MLB purposefully delays pitch location information for a few seconds for games using the challenge system. To even start to try to cheat the system, a team would need to go through the trouble of engineering their own pitch-tracking system that perfectly matches the system MLB is using and then find a way to relay that information to players in a split-second.

No system is foolproof, but attempts to cheat the ABS challenge system would be difficult, to say the least.

Myth No. 6: Full Robot Umps Are Coming Soon 

MLB has been experimenting with full ABS systems in games since 2019, when the Atlantic League adopted it in consultation with MLB. It has tried them in the Florida State League, as well as in Triple-A.

In every case, MLB decided to end the experiment. Full ABS systems have never seemed to provide exactly the strike zone everyone wanted to see. And time after time, the ABS challenge system was found to be preferable.

So far, feedback MLB has received from players, coaches, umpires and front offices has been a preference for the challenge system.

“The ABS system (without the challenges) is very boring,” said Robert Stock, who pitched under the ABS system for Triple-A Worcester and Nashville. “But adding in the challenges adds an element of skill (strike zone knowledge) and puts it at the forefront of the game.”

MLB has long used the minors to ensure that any issues with rules changes are discovered and fixed before the system comes to MLB. That was true with pitch clocks, shift restrictions, larger bases, liberalized base stealing rules and other more minor tweaks. As such, it’s notable that MLB is not using or experimenting with a full ABS system anywhere at this time. If a full ABS system was to be implemented in the major leagues, it almost certainly would be used in the minors first. And again, MLB tried that already and then killed their full ABS testing, replacing them with the challenge system.

MLB commissioner Rob Manfred has mentioned on multiple occasions that a full ABS system would create ripple effects for players, teams and umpires. 

He and others within MLB have noted that, given a choice, a modest change that also manages to ensure the most egregious missed calls are overturned is preferable to a system that devalues certain current players.

For instance, top framers like Giants catcher Patrick Bailey would see their value as a catcher plummet immediately. The best home plate umpires would also see a skill they have developed over decades rendered meaningless.

“I think the ABS system has its ups and downs, but overall itâ€s good for the game because it keeps everyone accountable,” said a Triple-A pitcher with experience under the challenge system. “Yeah, it takes away some of the catcherâ€s framing, but having a consistent zone makes sure pitches are called right or wrong without all the gray area. You see big league games flipped by missed calls, and thatâ€s where having a clear answer really matters.

“Thereâ€s some strategy with the challenges, and as a pitcher, you definitely go through a little adjustment period on pitches you think are strikes. But the zone stays pretty fair. And when umpires get overturned and have to announce it to the whole stadium, that adds a whole new layer of accountability too. At the end of the day, being able to fix those big calls is a huge plus for the game.”

5 New Realities With ABS

Ok, so we know the ABS challenge system won’t destroy the very fabric of baseball as we know it. But there will be changes that come with it, too, just as there are with any change. Here are some new realities that weâ€ve seen in Triple-A.

1. It Will Be Harder To Get Called Strikes

The adoption of ABS has meant that, for the past several years, the Triple-A strike zone has been very challenging for pitchers. Pitches on the border of the zone that may induce an umpire in the majors to call a strike are consistently called balls in Triple-A.

The challenge system gives umpires constant feedback on whatâ€s a ball and whatâ€s a strike. No one wants to be consistently proven wrong on the jumbo video screen, so umpires quickly adapted.

“The zone in Triple-A is actually smaller than in the big leagues, so the mentality has to be filling it up and still finding swing-and-miss,†added the Triple-A pitcher.

However, as those adjustments have been coming to the MLB zone, the changes are getting much smaller. The number of called strikes in the shadow zone at the MLB level has dropped from 46.4% in 2024 to 42.2% in 2025. In Triple-A, the called strike rate on pitches in the shadow zone has hovered around 44% for the past three years.

2. There’s A Strategy To Challenging Pitches

From what we’ve seen in ABS challenge system testing, a bad call on a 1-0 or 0-1 pitch often doesnâ€t get challenged. Even a borderline call late in the count of early innings will often go unchallenged because teams donâ€t want to use up all their challenges too quickly.

In 2025, there were 650 called strikes that went unchallenged on pitches that were in the “chase†and “waste†zones, while there were three pitches called balls on pitches right in the middle of the zone. All were pitches that would have undoubtedly been overturned if challenged, but the pitching team decided it didnâ€t want to risk a challenge.

Teams also have to establish a strategy about who gets to initiate challenges. As noted above, only catchers, pitchers and hitters are allowed to make a challenge. In Triple-A, weâ€ve heard stories of hitters who have been told to never challenge pitches because they are so bad at it. Some teams want the catcher to be responsible for challenges instead of the pitcher.

Hypothetically, a player with a bad sense of the strike zone can burn through the entire teamâ€s allotment of challenges in a single at-bat without some guardrails.

“Early in a game, if a catcher isnâ€t absolutely sure, theyâ€re not going to burn one,” said the Triple-A pitcher. “You might need that in a 4-3 game in the ninth.”

Because of that, players with the best strike zone knowledge may be at a strategic advantage.

“Itâ€s going to be very fun to see which players have good strike zone knowledge,” Stock said. “For instance, does Juan Soto have immaculate knowledge of the zone? Or is he just really good at taking anything close, both balls and strikes alike? I canâ€t wait to find out.”

3. Expect Less Arguing Over Calls

The constant back-and-forth between hitters, catchers and pitchers trying to work the umpire and complain about questionable calls fades away when an ABS system is in effect.

If a player thinks the umpire blew the call, he can just challenge it. Within 10 seconds, thereâ€s an answer. If the player was right, the call is overturned and the game continues. If the player was wrong, the umpireâ€s call is confirmed and the player has no further reason to complain. Itâ€s hard to carry a grudge from a call in the fourth inning into your next at-bat if you had the means of correcting it and you didnâ€t feel convinced enough to challenge the call.

“Thereâ€s 99% less (complaining) from the dugouts about the strike zone,” Stock said. “If you donâ€t like a call, then challenge it. And Iâ€m sure itâ€s humbling for a player to really miss a call by a large margin.â€

4. Challenges Add Drama To The Game

One entertaining side effect of the way the ABS system is used is that it gets fans involved, too, as they see the decision made at the same time as the players and umpires. Once the pitcher, catcher or hitter taps their head, the umpire stands up and announces that the pitch has been challenged.

At that point, everyone turns to watch the jumbo video screen in the outfield. The animation shows the pitch come in, and only when it crosses the plate do you see the pitchâ€s location. Sometimes, the call is so borderline that it takes a moment to realize whether the pitch nicked the strike zone or not.

In general, crowds seem to enjoy the drama of the moment. Because there are few challenges, it doesnâ€t get repetitive, but in a crucial moment, itâ€s a nerve-wracking few seconds in which everyone in the crowd (and on both teams) waits to see the answer unveiled in real time.

If that’s an exciting thing to see play out during a Tuesday game in April, just imagine the drama when a crucial strike three call gets put up on the jumbotron in the late innings of a winner-takes-all postseason game.

5. The ABS Challenge System Reinforces How Good Umpires Are

Every now and then in Triple-A, you will see a challenge on a clearly blown call. But much more often, though, challenges come on pitches that have either grazed the corner of the zone or just missed it. Iâ€ve personally witnessed challenges in Triple-A for which I needed to be told if the pitch was a ball or a strike after the pitch location was shown up on the big screen—thatâ€s how close to the edge of the zone a pitch can be.

Many of these calls are being made on pitches that either miss or touch the strike zone by the narrowest of margins. While the ABS system is designed to ensure that an egregiously bad call doesnâ€t affect the game, it also ends up showing just how talented the game’s top-tier pitchers, catchers, hitters and umpires are.

(Geoff Pontes contributed to this story)

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