Major League Baseball has officially done it; the ABS Challenge System is coming to the majors in 2026. The system allows teams to challenge the ball/strike call of the home plate umpire throughout the game on a limited basis. Much like the video replay review system, teams lose a challenge if they challenge the call and it turns out the umpire was right.

How it works

The ABS is technically not what has been referred to as the “RoboUmp.” That system uses the same setup, but calls every pitch in the game, completely taking balls and strikes out of the home plate umpire and gives it to the ABS system. With the challenge system, the hitter, catcher, and pitcher all have the ability to challenge any ball or strike call. Here’s the catch; each team gets two challenges per game and if the call is confirmed, they lose a challenge. If the call is overturned, the team retains that challenge.

Another part of the system is that the challenge must be done immediately. In the minors, they meant immediately, too. If it takes too long, or if the home plate umpire thinks that the player who challenged was given any help from the dugout or a player, the challenge is denied. On the replay reviews teams can have the umpires hold up the game for as long as 15 seconds to determine whether they want to challenge. Not with the ABS challenge. Especially late in the season, umpires were not giving any leniency to the amount of time that is allowed to challenge. In an IronPigs game during the last week of the season, a player on the Syracuse Mets appeared to look into the dugout prior to challenging and the umpire denied the challenge, allowing the strike call to stand.

To signal for a challenge, the batter, catcher or pitcher simply tops the top of their helmet/hat to start the challenge. The umpire then announces the challenge just as he would a review. Instead of a replay coming up on the video board, a graphic of the pitch and where it was compared to the strike zone is shown and the call is either confirmed or overturned. In the minors, the video also showed how far out of the strike zone the pitch was. Since every pitch is open to a challenge, on a 3-2 pitch a walk can turn into a strikeout or change a strikeout into a walk.

What to expect

  • You’re going to see – much like we have with replay – that the umpires are actually pretty good. Most calls that are overturned from a strike to a ball are less than an inch out of the strike zone. Covering a lot of Triple-A games, I have seen a few pitches that were a ball by 0.10 inches. You can’t really blame the human eye for missing that one.
  • We’re used to replay reviews taking a while. Not so with the ABS. It all goes very quickly and the call is not arguable or changeable. If ABS says it’s a strike, then it’s a strike.
  • Pitchers are not good at challenging pitches. Whether it’s partiality or just being further away, most pitcher challenges are confirmed as a ball. It’s probably best to leave that to the team’s catcher. On a similar note, you will find that some catchers and hitters really are good at judging the pitch and some aren’t. Truly, some players do have a “good eye.”
  • Yes, the system is adjusted to the height of the batter. In other words, the strike zone for Aaron Judge will be different than the one for Edmundo Sosa. While some say that it varies by stadium, it’s not supposed to. The cameras are at the same angles in every park and it is the same system in every ballpark. Plus, the whole thing is supposed to be calibrated on a regular schedule.
  • The ball/strike zone shown on television is NOT official. Many broadcasters and fans believe it is, but it’s not. The ABS runs on its own system and can/will be different from the one on television.
  • Some teams/players simply will not challenge a call early in a game while others will. One theory is to save the challenges for key spots in the game, but who is to say that a call in the first or second inning won’t turn out to be a big pitch? I have seen teams use up their challenges by the second inning and then not be able to challenge a call in the eighth or ninth.

A lot of fans actually get into playing along with the challenge. I have to admit that I was not the greatest at judging balls and strikes, but then I was up in the box and not behind the plate – they tend to not let me go back there. Everyone has an opinion on ABS challenges. When it was introduced, I didn’t like it. I felt it took the human element of the umpire – good or bad – out of the game. But the first time you see your team get a key call in a big situation, you will realize the value that it has. Of course, if that call goes the other way, you realize the pain that the system has.

One final note. There was some talk that if the ABS system was going to be used, the umpires would actually prefer that it be used full-time with the umpire just echoing what the system tells him to call. That way, the umpires weren’t being made to look bad if they blew a call. Actually, most umpires are okay with the system. Believe it or not, they want to get the call right just as much as the fans want the call to be correct.