May 6, 2025; Tampa, Florida, USA; Philadelphia Phillies pitcher Matt Strahm (25) and Philadelphia Phillies right fielder Nick Castellanos (8) react after beating the Tampa Bay Rays at George M. Steinbrenner Field. Mandatory Credit: Nathan Ray Seebeck-Imagn Images Nathan Ray Seebeck
The challenge-based automated ball-strike system (ABS) that Major League Baseball tested out during Spring Training and has been using for all Triple-A regular season games since June of 2024 will indeed be coming to the show in 2026.
These, per MLB, are the key points to remember of the ABS challenge system:
- Each team will get two challenges and can keep them if they're successful
- Challenges can only be initiated by a pitcher, catcher, or batter, and the request must come right after the pitch
- To signal a challenge, the pitcher, catcher, or batter will tap his hat or helmet to let the umpire know
- No help from the dugout or other players on the field is allowed
- In each extra inning, a team will be awarded a challenge if it has none remaining entering the inning
Rob Thomson on ABS challenge system coming to the majors next season: “I love it.”
(Via @TimKellySports) pic.twitter.com/5VQKUtJg3S
Phillies manager Rob Thomson was excited about Tuesday's announcement.
"I love it," Thomson said. "And I loved it in Spring Training. And I think not all the players, but I think most of the players if you ask them, they really liked it too. I think it keeps everybody accountable. It keeps everybody on their toes. I do like the added challenge during extra innings. I thought the umpires were really locked in during Spring Training. Hitters were really locked in during Spring Training. I thought it was great."
Thomson is correct in saying that there are plenty of players, particularly hitters, who seem to like the challenge system. But there are others, particularly pitchers, who seem to be opposed.
Earlier this month, new Phillie Walker Buehler expressed his disapproval of the system, which he had recently experienced during a start with Triple-A Lehigh Valley.
"I think it's inaccurate," Buehler said. "I think most of the stadiums it's not even actually on the plate — I think it shifts certain directions in certain ballparks. I think the human element is a huge part of this game. I think starting pitchers that have pitched for a long time deserve certain parts of the plate that other guys don't get. When I got to the big leagues, I didn't get every part of the zone that others guys did, and I think that's part of our game and should be. I think the punishment for challenging something that's clearly a strike is not big enough. I could kinda go on.
"I think the ABS system in general is a very good idea," Buehler added. "I don't think we have any idea where to put it on the plate. I don't think we have any idea how to function it correctly in terms of the angles of ballparks. I don't think the umpires unions are going to be very happy about it. So there's a lot of negatives about the ABS."
Walker Buehler … not a fan of ABS.
(Via @TimKellySports) pic.twitter.com/Z2qC55nY0V
It should be pointed out that the ABS system is not 100% accurate. In a May story for The Athletic, Ken Rosenthal and Jayson Stark spoke to former NL Cy Young Award winner Corbin Burnes — who is on the joint competition committee — and he said that ABS has a previously unreported margin for error of "close to a half-inch." How baseball plans to address that, among other concerns, will be an interesting angle now that the system is indeed coming to the majors in 2026.
Matt Strahm is one of those like Buehler who isn't in favor of the system, saying "it's not baseball."
"You don't have any mound in the league that's the same. We don't have any field that's graded the same. So it just doesn't make sense," Strahm said. "But again, I'm not a nerd. I'm just a JUCO kid that plays baseball."
Strahm continued, sharing a similar concern about how the system will vary from stadium to stadium as Buehler had.
"Cincinnati, I believe, is graded to home plate, so all the water runs. That's why the dugouts flood and everything. So home plate is lower already. So the mound is not as big. So is that going to affect it? Do you know? I don't think anybody knows either, so how are we gonna do it?"
The counter to Strahm, a former All-Star in his 10th MLB season, was Nick Castellanos. Now wrapping up his 13th MLB season, Castellanos said he like ABS during Spring Training.
"I definitely think that it might keep umpires locked in a little bit more if their decision can be challenged," Castellanos said. "We're in a competitive sport, I always view accountability as a good thing."
More experienced than both of them is David Robertson, a 40-year-old that entered the league in 2008, six years before the challenge system was instituted. Home run replay reviews began in August of 2008, but the umpire had to decide to review it or not. Managers could ask, but ultimately the umpire had to decide whether to review it because there weren't any challenges. It was also only for home runs, not out/safe calls, or fair/foul calls that weren't home runs.
Robertson wasn't with a club during Spring Training, but the 17-year MLB vet did get to experience the ABS system when he was tuning up with Triple-A Lehigh Valley during the summer. Robertson did challenge a pitch while with the IronPigs, but ultimately came away preferring things stay how they've always been in the sport.
"Personally, I don't like it," Robertson said. "I don't really like any of the changes they put into baseball, but that's only because I played six or seven years without anything, right? And then everything's changed, it seems very quickly. Either that or I've just been here a long time. I mean, if that's what all the young guys want, great. If that's what MLB is trying to push in, that sucks. I would want to do what everyone else would want to do. I just know that once you put something in, it's very hard to get rid of it."
Robertson went on to say that he believes umpires generally get the calls right, while also observing that the zone has tightened up at Triple-A due to the system and that's led to "a ton of walks," dragging the game out. Strahm hasn't experienced the system at Triple-A, but also shared frustration with what he views as a shrinking zone. He said "if you want to use a strike zone, use the one in the rule book," alluding to the bottom of the letters to knees zone.
Weston Wilson doesn't have the same experience level in the majors as any of the other veterans who spoke to On Pattison for this story. However, between Spring Training and stints at Triple-A in both 2024 and 2025, he's experienced the ABS challenge system probably more than everyone else combined. Just a few lockers down from Robertson, Wilson shared his perspective.
"I think it keeps things ... it makes the umpire lock in a little bit more, I guess you could say," Wilson said. "Because he knows that if he makes some egregious call, he's gonna get embarrassed. Same thing for us. I think the biggest thing is it gives an opportunity to ... let's say the bases are loaded in like the eighth inning and there's two outs and a guy strikes out on a horrible pitch. I think that's where it's good that it can be used. Because it's not fair if a guy takes a ball that's three balls inside and that gets called a strike. You shouldn't strike out over that with bases loaded, you know what I'm saying?
"Same thing goes for pitchers," Wilson added. "If he throws a 2-2 pitch and it gets balled but it's inside the zone, there's an opportunity for the catcher and pitcher to challenge that. So overall, I thought that it made the strike zone more accurate. I think the misses were smaller. Maybe there's just as many misses, I don't know, but they're not going to be massive."
Ultimately, like the pitch clock, extra-innings zombie runner, universal DH, three-batter minimum and shift restrictions before it, players will have to adjust to the latest controversial rule change. This system is coming in 2026, even with some very real trepidation from some.
"We'll have to wait and see," Robertson said. "For me personally, I'm not a fan."
