MLB To Implement ABS Challenge System in 2026

After testing the system for two seasons in Triple-A, Major League Baseball has decided to implement the ABS (Automated Ball-Strike) challenge system at the start of next year’s season.

Since the system was first integrated into professional baseball games, MLB has slowly been more open to testing it with big league players. For example, we saw the challenge system used in MLB spring training games for the first time earlier in 2025, and it was also available for use during the MLB All-Star Game in July.

The Joint Competition Committee has now voted to bring the system to the big leagues, citing its success in the minor leagues as a big reason. For traditional and new-age fans, the challenge system appears to be the perfect combination of robot umpires and the traditional game we all know and love.

How will the system work once implemented? What type of effect could it have on the game? Let’s dive in and answer all of these questions.

How the ABS Challenge System Works

The way the ABS challenge system works is fairly simple overall. MLB uses Hawk-Eye systems in each stadium that can accurately track pitches, which is how we get all publicly available Statcast data. Since we have this accurately tracked pitch location data, we can determine whether or not a ball was in the zone or off the plate.

When a player disagrees with a call, all they must do is tap the top of their head to signal they want to challenge the pitch. Then, a graphic will be shown on the scoreboard, showing the location of the pitch. If the player is correct, the team will maintain their challenge, and the call will be overturned.

It’s important to note that these challenges can only be initiated by the batter, catcher, and pitcher. No person other than these three people can initiate a challenge, adding another level of strategy to the system. If it weren’t for this, teams could use the technology in the dugout to see each pitch’s location, which essentially would create a fully automated ball-strike system.

Each team will begin the game with two challenges. If a team enters extra innings without a challenge, they’ll be given one for that inning. If they lose that challenge, they’ll be given another for the next inning, with this cycle repeating. However, if a team still has challenges remaining when they enter extra innings, no extra challenges will be given to that team until they enter an inning without a challenge.

The ABS challenge system will be used in every stadium and game that’s played. Yes, you heard that right, even the postseason. This means that in some of the sport’s biggest spots, players will receive the most accurate calls possible.

For those concerned about the ABS challenge system adding extra time to games, fear not. The challenges happen so rapidly that each one added an average of just under 14 seconds to games when tested in spring training earlier this year.

The ABS challenge system appears to be baseball’s perfect middle ground between full automation and the human side of the game. For fans, this system will be quite the exciting new addition to America’s pastime.

Potential Implications

Now that we know how the system will actually work, it’s time to discuss some of the potential impacts we’ll see on the field in next year’s games.

The clearest difference is that instances of bad home plate umpiring completely changing the outcome of a game will become rarer. As long as players are smart with when they use their challenges, fewer contests will be decided by this aspect of the game.

For hitters who know their strike zones very well, you’ll likely see them pick up a couple more walks, or at least some more at-bats with the count in their favor. The same effect extends to pitchers who know the zone well, as they could have a few extra strikeouts or favorable counts.

If you’ve been a baseball fan for long, you’ve surely heard fans complaining about rallies being interrupted by umpires’ bad zones. As long as players don’t blow through their challenges, future rallies may not be interrupted as much, as incorrect calls can now be overturned.

The same will be true during the MLB playoffs, when the stakes are even higher.

Another thing you may have heard about over the years is that veterans are often given more favorable strike zones. This slim advantage will begin to disappear, as these favorable calls can be overturned. The same can be said for potential instances of strike-zone-related rookie hazing.

Overall, the ABS challenge system has the potential to be one of the best rules implemented in recent memory. Players, teams, and fans will all fall victim to fewer bad calls, without compromising on the human aspect so many fans love. The impact will be huge, though only time will tell just how big an impact it will have on our sport.