For a couple of seasons now, minor league players have had to deal with the Automated Ball-Strike System (ABS) and what is known as the “challenge system.” Not sure on how ABS works? Basically, it’s a video and computer system that is installed at ballparks that can tell whether a pitch is a ball or a strike; it even takes the hitter’s personal strike zone, which is determined by their height, into account. In other words, the strike zone for Aaron Judge (6′ 7″) will be very different from that of Rafael Marchan (5′ 9″).
The system is capable of calling every pitch, and for a while they experimented with that in the minors. Instead, they went with the challenge system where the three most involved players in each pitch – the catcher, pitcher, and hitter – can challenge the umpire’s call. When that happens, the ABS system shows the pitch on the video board and the ruling of the system stands. If the player is correct and the umpire’s call is overturned, then the team does not lose a challenge (they have two per game), but if the call is upheld, then they lose a challenge.
Major League players will be using the ABS system in 2026 and it’s going to bring some more strategy into the game. In the minors, it’s not unusual for a team to blow through both challenges early in the game and not have any remaining for those close calls late in the game. The word was that some teams told their players not to challenge a call before a specific inning, while others just let the players decide. The challenge has to be instant and players are not allowed to look into the dugout for any guidance, though some did try to do just that and the umpires were wise to it and disallowed the challenge.
Baseball Trends, Part 1: The Impact of Rule Changes on Stolen Bases
For catchers, it will slightly dampen their ability to frame pitches, something that some catchers pride themselves on. J.T. Realmuto for one is considered to be a master framer who gets calls for their pitchers. Now, a hitter could challenge that and possibly get the call overturned. But again, it has to be instant and each team has just two challenges, and lose one if the umpire turned out to make the right call. And yes, umpires do sometimes disallow challenges if the player takes too long to give the signal – tapping the top of his head – that he wants to challenge.
As expected, the umpires and their union had some concerns. If a home plate umpire is having a bad day challenges may reinforce their missed calls and the fans are quick to let them hear it. Many times though, it turns out that the umpires get the call correct. When they don’t the margin between the pitch being a ball or a strike can be as small as one-hundredth of an inch. That information is also shown on the video board.
Some umpires would have preferred if MLB went with the full ABS system and used it to call each pitch. Under that system, the umpire is given the call through an earpiece and makes the call on the field with no challenges by players.
A funny thing about the ABS challenge system
Baseball put the ABS system into minor league baseball in 2023. At first, Tuesday through Thursday games used the challenge system while Friday through Sunday games used the challenge system. Perhaps the most interesting thing to come out of the ’23 season was the walk rate. Triple-A pitchers issued walks at a rate of 12% compared to the 9.7% level in 2022. It was attributed to the ABS system not allowing as many high strikes as its human colleagues.
In 2024, baseball went with the full challenge system and no fully automated ball and strike calls. The walk percentage leveled off at right around the 12% level. As players seemed to adjust to the ABS challenge system, walk rates have come down to around 10.5% in Triple-A baseball as of last season. In the recently completed Arizona Fall League where they used the ABS challenge system, the walk rate was around 15%. It needs to be noted though that the league is somewhat infamous for pitchers issuing walks, which is a little strange since most of the players are premier prospects.
In any event, don’t be surprised to see walk rates increase in the majors in 2026. It may be tempered slightly because some of the players now in the majors dealt with the system in the minors. Rest assured though that the ABS system is going to be a point of discussion around Major League Baseball this coming season.
Please scroll down to comment on this story or to give it a rating. We appreciate your feedback!
Disclaimer: Some of the products featured or linked on this website may generate income for Philly Baseball News through affiliate commissions, sponsorships, or direct sales. We only promote items we believe in, but please assume that PBN may earn a cut from qualifying purchases that you make using a link on this site.
Privacy Policy | Contact us
© 2025 LV Sports Media. All rights reserved.
Philly Baseball News 