MLB 2026 Will See The ABS Challenge System Full-Time

Via MLB (Getty Images)

NEW YORK, NY: For the 2026 MLB season, the ABS Challenge System has been confirmed. After years of testing in the Minor Leagues and its implementation in MLB Spring Training and this year's All-Star Game, the Joint Competition Committee approved Tuesday afternoon to introduce the Automated Ball-Strike (ABS) Challenge System, powered by T-Mobile, to the major leagues.

MLB Commissioner Rob Manfred stated in a statement that "the previous rule changes that have been adopted by the Joint Competition Committee have had staying power and created momentum for the game." "We followed the same procedure with ABS, which began with fan feedback, extensive Minor League testing, and constant efforts to improve the game. We have worked to implement the system in a way that gamers will find acceptable during this process. The system we are announcing today was largely determined by the players' strong preference for the Challenge format over calling every pitch with technology.

The ABS Challenge System allows teams to request a quick review of some of the most crucial ball-strike calls in a particular game, which is seen as a compromise between the long-standing tradition of human error that comes with human umps and so-called "robot umps" that could call every ball and strike.

A 5G private network from T-Mobile for Business' Advanced Network Solutions powers the ABS Challenge System. This will be the first time the home-plate umpire's ball-strike calls will not be finalized during the championship season at the highest level of the game, despite the fact that MLB has had video replay reviews since 2008. Players can ask for a challenge of a ball or strike call they believe the umpire made incorrectly thanks to Hawk-Eye technology, which operates in the background and tracks each pitch's precise location in relation to the batter's zone.

T-Mobile's Advanced Network Solutions then sends the Hawk-Eye view across a 5G private network when a call is contested, and it is displayed almost instantly to those present via the videoboard and to viewers at home via the broadcast. The game continues with only a brief interruption once the ball-strike call is either confirmed or overturned.

Mike Katz, T-Mobile's president of marketing, strategy, and products, stated, "We've achieved a lot through our longstanding partnership with MLB, and the rollout of ABS -- powered by T-Mobile 5G -- is one of our most exciting milestones yet." It's a compelling illustration of how we're leveraging technology to support MLB's innovation while maintaining the essence of the game we love. And only America's Best Network's size and dependability make it feasible."

This is a summary of the ABS Challenge System's operation and the specifics of the system that MLB will employ.

How many challenges are given to each team?

The game will begin with two challenges for each team.

In extra innings, do teams face an additional challenge?

Any team that begins the extra inning without challenges will receive one challenge for the tenth inning if the game goes into extra innings. They will be given another challenge for the eleventh if they finish that one, and so on. A team will not receive an extra challenge for the 10th inning if they have challenges left at the beginning of the inning, but they will receive one for any inning after that if they are out of challenges at the beginning of the inning.

Will every MLB game at every ballpark employ the ABS Challenge System?

Indeed.

And in the postseason?

Yes, too.

Who has the authority to challenge?

An umpire's call may be contested by the catcher, pitcher, or batter. No one else is allowed to do so, not even the management. After the umpire's call, challenges must be made right away, without help from the dugout or other players.

How does one offer a challenge?

To let the umpire know that he wants to contest the call, the player taps his cap or helmet.

How is the call evaluated?

The video board shows the animated pitch result graphic to those there, while the broadcast shows it to viewers at home.

How long does it take to play the game after reading the review?

During Spring Training 2025, 288 games were played using the ABS Challenge System. On average, each game had 4.1 tasks, and the average time to complete those challenges was 13.8 seconds.

Are challenges that are successful kept?

Indeed. Only when the umpire's call is verified does a team forfeit their challenge. It is the player's responsibility to ask for challenges wisely because they can be lost; that is, to avoid "wasting" them in a low-leverage location so that his team can use them in a high-leverage spot. Thus, the ABS Challenge System gives the sport a strategic element.

During Spring Training, how was the Challenge System received?

72% of MLB's Spring Training fan poll respondents believed the Challenge System improved their experience. In contrast to 31% who supported sticking with human umpires, 69% of respondents stated they would like to see the sport continue using ABS going forward.

How long did the Minor Leagues test this?

In 2019, the independent Atlantic League was the first to implement the entire ABS system. In 2022, the Florida State League implemented the Challenge System for the first time. The Challenge System and complete ABS were tested during the 2023 and 2024 Triple-A seasons. Full ABS was abandoned at the end of 2024 in favor of the Challenge System, which remained in use in 2025.

How did MLB decide that each team may have two challenges?

Before 2025, MLB tried two challenges per team per game and three challenges per team per game at the MiLB level. The average number of challenges in three-challenge games was 5.8, whereas the average number of challenges in two-challenge games was 3.9. According to 71% of Triple-A game attendees surveyed, there should be no more than four difficulties in each game. While three-challenge games only passed this criterion 30% of the time, two-challenge games did so 62% of the time.

What is the difference between this and the human umpire zone?

The umpire-called zone, which has a minimum of 24.2% at the bottom and a maximum of 55.6% at the top, has typically been more rounded and forgiving of pitchers. MLB research showed that in 2-2 counts, the ABS zone was 443 square inches and the umpire-called zone was 449 square inches. This shows how this might affect a crucial call.

In what ways does the ABS zone take player height into consideration?

Every position player's height is measured during Spring Training camps. A group of impartial testers first takes manual measurements, and then representatives from a research institute use biomechanical analysis to validate the manual measurements and prevent any manipulation. Without cleats, players are measured while standing upright.

In conclusion, the ABS System is coming to Major League Baseball full time. The game is evolving and it will certainly be interesting to see how this change develops. Welcome to Major League Baseball in 2026.