In 2026, however, ABS will make its major league regular season debut.

Minor league players have been using the automated balls and strikes system for years now, but there will certainly be a learning curve for established veterans who have never used it beyond Spring Training.

Ultimately, Minnesota Twins manager Derek Shelton will decide how he wants to utilize Major League Baseball’s new challenge system, something he still has some time to think about both before and after exhibition games are played.

Derek Shelton won’t let MN Twins pitchers challenge balls/strikes?

Technically, during any one at-bat where a team has challenges remaining, any of the involved pitcher, hitter or catcher are eligible to challenge a ball or strike. But if Shelton gets the final say, it sounds like pitchers, specifically, will not be allowed to make challenges from the mound for the Twins.

“My early thought — I don’t know if I should say this — I don’t think the pitchers should ever challenge. Pitchers think everything is a strike.” 

Derek Shelton (via Star Tribune)

Shelton believes that pitchers are too emotionally tied to the outcome of each individual offering, to be in charge of challenging an umpire’s original call.

Beyond that, catchers have a better view of what is a ball vs strike, than their teammate. Thus, it does make a lot of sense to take the option to challenge out of a pitcher’s hand altogether.

The Star Tribune’s Bobby Nightengale, who sat down with Shelton for his weekly Extra Innings newsletter, brought some pretty convincing data to help strengthen the new skipper’s argument against pitchers challenging.

When the automated strike zone challenge system was tested during spring training last year, MLB reported the overturn rate was 52.2%. Catchers had a 56% success rate on their challenges, and pitchers had a 41% success rate. Hitters were successful in exactly half their challenges. 

Bobby Nightengale – Star Tribune

Having watched hitters challenge pitches over the past couple of years in St. Paul, it has also been impressive to see their accuracy. It’s incredible how well professionals know their individual strike zones. It’s also consistently apparent how small the margin of error for umpires is.

THANK YOU BASEBALL GODS THE ABS CHALLENGE SYSTEM IS FINALLY BEING TESTED IN MLB GAMES pic.twitter.com/d5Fa0kq6cz

— Codify (@CodifyBaseball) February 20, 2025

As the Minnesota Twins get into spring training, we’ll see if Shelton softens his stance on pitchers challenging. One thing is for sure, as I’ve watched the ABS challenge system rolled out in St. Paul with the Saints, is just how advanced most hitters’ feel for the strike zone really is — not to mention how small the margin of error is for umpires, at that level.

Could Twins generate advantage through ABS?

Just how quickly teams adapt to the new rules will create competitive advantages throughout the league, especially early on after adoption. Situational circumstances and end game results are something that Shelton and Arizona Diamondbacks manager Torey Lovullo both opined on recently.

“I just don’t want somebody up there randomly in the bottom of the second inning wasting our last challenge and saying that’s the end of it.”

Torey Lovullo – Star Tribune

“I don’t know if anybody has an idea. I guarantee you’re going to see a lot of copycat. You’re going to see every organization watching other organizations and how they attack it. I do think in the first month, month and a half, teams that figure it out are definitely going to have an advantage.” 

Derek Shelton – Star Tribune

The ABS challenge system won’t take away catcher framing, because there are only so many challenges allotted to each team every game. For a team operating on the fringes like the Twins, they need to be at the forefront of any advantages the new challenge system can bring.

If you have watched any St. Paul Saints action over the last year, then you have seen both the replay and expanded version of the ABS system in play. Now we’ll see how it effects the highest level of baseball.

Related: How to Watch the Minnesota Twins Spring Training in 2025

What is the ABS system?

Baseball’s long been ruled by umpires, but that’s come with flaws—Twins fans have felt the sting more than most. A glance at Ump Scorecards postgame often stirs frustration. Now, technology’s here, and has been, to hold umpires accountable and finally get it right.

The ABS system isn’t the same as robot umpires. It keeps the human element in play and adds a twist by challenging it. Instead of switching to full automation, ABS gives batters, catchers, and pitchers the power to question a call, all within the flow of the game.

• During the spring, each team will be given two challenges per game and will retain successful challenges.

• Only the batter, catcher or pitcher can initiate a challenge, which must happen immediately after the umpire’s call. The player must quickly tap his hat or helmet to indicate a challenge.

• The results of the challenge will be displayed on the scoreboard and television broadcast to communicate whether a call was overturned or not.

Courtesy: ESPN

Hawk-Eye technology has been present in Major League Baseball stadiums since 2019. It works alongside Statcast to provide tracking data all over different aspects of the game.

Related: 2025 Minnesota Twins Opening Day Roster Projection (1.0)

With the ABS challenge system, the umpire is not simply regurgitating a call made through the Hawk-Eye technology. Only when a player instigates a challenge is the technology put into use. The result is a quick and efficient representation on the scoreboard. The game then continues on.

Why the ABS challenge system?

Major League Baseball isn’t interested in removing the human element of umpires, and they shouldn’t be. A level of accountability not currently present is necessary, however.

By allowing players to challenge the human eye of umpires, there is a greater opportunity for everyone to feel satisfied with the result.

Baseball gets better this spring. pic.twitter.com/7t28PSGifn

— Ted (@tlschwerz) February 19, 2025

This is a non-invasive way to impact the game. Major League Baseball has suggested that just 17 seconds of game time are added through the ABS challenge system. The construction of this method allows for catcher framing effectiveness to remain in place, but gives everyone an opportunity to question the result.

Related: Minnesota Twins Offseason Gets Dismal Grade From Expert

Umpires, all union members, hold onto their jobs but face a new layer of scrutiny. The league can now tweak things for those faltering under the system. Teams will feel it too, as coaching staffs adjust their trust in player initiated challenges based on the results.

When will we see ABS in MLB for good?

Right now the ABS system is just in a trial period at the big league level. This is being instituted for the first time this spring, and the Minnesota Twins will see it throughout Grapefruit League play.

During the regular season, ABS will not be present at the highest level. However, Triple-A play will continue to use the ABS challenge system and compile as much data for Major League Baseball as possible. Full ABS went away at Triple-A in 2024 as it was deemed unnecessary.

The challenge system will be in play from the jump at Triple-A, and Major League Baseball will then decide on its usage at the highest level prior to the 2026 season.

Related: How to Watch the Minnesota Twins MLB Spring Training in 2025

Spring Training presents a good testing ground for Major League Baseball, and will give many fans a look at something they have previously never seen. It could become the norm next year.