ABS to Be Implemented in 2026: Many of Baseball’s Best Defenders Just Became Expendable
By Jack Zinke | 30 September, 2025
A new era of baseball is upon us. In an effort to appease fans’ growing frustrations concerning the performance of umpires, MLB announced on September 23 that T-Mobile’s Automated Ball-Strike (ABS) Challenge System will be implemented on Opening Day in 2026. Overall, the move has been well received by fans across the country; however, the underlying effects of such a drastic change will undoubtedly alter the defensive value of the catcher position. Will front offices opt for above average offense in place of defensive stalwarts behind the plate in 2026? Only time will tell.
Essentially, ABS allows the batter, pitcher, or catcher to challenge a ball or strike call at any point in the game. Each team will receive two challenges per game and will retain their challenge if successful. An unsuccessful attempt will result in losing one of the two challenges. It allows players to take some control of the game and take some control away from the umpire. ABS will virtually serve as the middle ground between the traditional umpire and ‘robo-umps.’ The process of how T-Mobile’s ABS will function in-game was described by MLB writer Anthony Castrovince:
“When a call is challenged, the Hawk-Eye view is then transmitted over a 5G private network from T-Mobile’s Advanced Network Solutions and nearly instantaneously shown to those in attendance via the videoboard and to home viewers via the broadcast. The ball-strike call is then either confirmed or overturned, and the game goes on having only been briefly interrupted.”
T-Mobile’s Automated Ball-Strike (ABS) Challenge System as would be displayed on Major League videoboards when reviewing challenges. (MLB/T-Mobile)
ABS was tested in MLB Spring Training games in 2025 and the results were encouraging. A challenge only added approximately 14 seconds to the length of the game and just 4.1 challenges occurred per game, extending games by approximately 1 minute. 52.2% of ball-strike challenges were successfully overturned, just a little over half of all challenges. Lastly, while challenges were consistently used throughout the game and not just saved for later innings, the amount of successful challenges decreased as the game went on. Overall, Spring Training had encouraging enough results that MLB made the decision to bring ABS to MLB permanently in 2026.
Many have voiced concerns surrounding the abandonment of the long-standing tradition of human umpires calling games in real time. However, this is not a swap of humans and robots. Furthermore, limiting each teams’ amount of challenges allows the human element of baseball to remain. Umpires will still be able to establish their own strike zones (to an extent), batters, pitchers, and catchers will need to strategically use their challenges, and maybe most importantly, catchers will still be able to frame pitches. But, the real question is, will pitch framing still have a large impact on determining whether a pitch is called a ball or strike?
Retired MLB umpire Angel Hernandez was a controversial figure in baseball throughout his 30-year career. (MLB)
Catchers who can block balls in the dirt, throw out runners, make clean tags at the plate, and frame pitches effectively are typically good defensive players. These are the key attributes that make up a quality defensive backstop. With the implementation of ABS, however, the ability to frame pitches will almost certainly not be as important to a catcher’s skillset as it has been in the past. In baseball’s history, a catcher that can frame pitches well can completely change the way that an umpire calls balls and strikes. They do this by practically making a ball look like a strike or making a borderline strike look as if it was right down the middle of the strike zone. This advantage that an effective pitch framer gives to his pitcher is now void when a call is challenged. It won’t even matter if the catcher made a ball appear as if it were actually a strike, because ABS will inevitably overturn the call. Pitch framing will only have an effect on the game if a call goes unchallenged.
Because of this substantial rule change, the catcher position is going to be looked at in a new light by front office executives. In the past, many organizations have opted to sacrifice offensive contributions of a hitting-first catcher for the defensive abilities that another catcher might provide. Rarely does a catcher possess both elite defensive and offensive skills. For this reason, executives must weigh the pros and cons of fielding an offense-first catcher versus a defense-first catcher.
Each year, catchers as a whole typically finish last in hitting metrics among all positions, signaling that teams are willing to sacrifice hitting if it means that a catcher can hold his own behind the plate. According to Statmuse, catchers ranked last among all positions (except pitchers) in 2025 in batting average (.236) and recorded the most strikeouts (5,018). Now, with a key defensive element losing significant value in 2026, it may be preferable to have a catcher who is better at the plate instead of behind it.
Gold Glove catcher Patrick Bailey of the San Francisco Giants is notorious for his elite pitch framing ability. This component of his game has made him one of the best defensive players in all of Major League Baseball. MLB writer David Adler wrote about Bailey’s defensive prowess back in August:
“There's an argument that Bailey is the most impactful fielder in baseball. By Statcast's Fielding Run Value, which combines all of the individual Statcast defensive metrics into one overall value stat, Bailey ranks No. 1 among all MLB fielders – not just catchers – both in 2025 and since his debut.”
Since his debut, Bailey ranks first among all MLB players in Fielding Run Value. (Statcast)
Despite this, Bailey’s hitting metrics are among the worst of all starting catchers. With the implementation of ABS, his elite defensive play might not be enough to make up for his subpar offensive production. With Bailey’s pitch framing ability being far less valuable to San Francisco after the introduction of ABS, his defensive production will most definitely take a dip in 2026, making the argument that his defensive play makes up for his lack of hitting a little less viable.
For this very reason, President of Baseball Operations Buster Posey may choose to platoon or even replace Bailey with a better hitting option behind the dish. Posey, a former Gold Glover, NL MVP, Silver Slugger, and all-time great catcher, certainly places value on hitting at the catcher position, so it is not out of the realm of possibility that Bailey, among other defense-first catchers, may be out of work in the near future.
The San Francisco Standard’s John Shea reported Bailey’s take on ABS in July:
“It takes a lot off my plate in a bad way. I think it takes a lot of value from the catching position that’s already, in my opinion, pretty undervalued. So, yeah, I think you’re going to see a lot of catchers out of baseball with the ABS.”
Even baseball’s best defensive catcher sees the landscape of the position drastically changing. The art of pitch framing will still exist, but just in a lesser capacity. It isn’t just Bailey, though, who should be worried about the move. Many other teams across the league are currently prioritizing solid defense from their catcher, a stance that will likely shift over the course of the offseason.
Personally, I believe that it is a good move for baseball to implement the Automated Ball-Strike Challenge System. It pleases both players and fans upset with the performance of umpires, while also retaining the human element that the umpire provides to the game. Players will use their challenges wisely as they only receive 2 per game. In my opinion, ABS is much more preferable to full ‘robo-umps.’ The signature strikeout calls, high-intensity ejections, and the overall drama that umpires add to MLB is essential to the game that baseball fans have come to know and love. ABS just holds umpires more accountable, something that should be warmly received by both players and fans alike in 2026.
