Major League Baseball is America’s national pastime, but even pastimes change to preserve their cultural relevance, and MLB is no different. A sport that was popularized during the Civil War era has tinkered with its rules over the years, including the designated hitter, a 15-second pitch clock, and a ghost runner for extra innings. Now, MLB has instituted a ‘robot umpire’ this season, and it is improving the game.
The automated balls and strikes system (ABS) is the official name of the new software that MLB is experimenting with for 2026. How it works is that every team is given two challenges per game to appeal a ball or strike call they believe the umpire got wrong.
Only a pitcher, catcher, or hitter can challenge a call, and they have 2 seconds to tap their hat or helmet to initiate an official review. The catch is that if you are wrong twice in a game, you are out of challenges. However, if you challenge the call and are correct, you get to keep them. If the game goes to extra innings, one is awarded to each team unless they already have both challenges remaining. They do not carry over to the successive inning if they are not used.
The official strike zone for ABS is somewhat different from what umpires have historically used in the past. Traditionally, the strike zone’s width is based on the width of home plate, 17 inches. The height of the strike zone is the rectangular midpoint between the shoulder blades and belt, and the lower level at the back of the knees.
While the ABS zone uses the same width from home plate, the length is determined by a batter’s height. Players underwent testing during spring training to certify official height measurements. For instance, Astros’ 2nd baseman Jose Altuve is 5’6” and Yankees outfielder Aaron Judge is 6’7″, which is a difference of 13 inches. Instead of an umpire using the eye test to do them by the same zone, they will be called by two different zones that are consistent with ABS.
Each ballpark is equipped with 12 Hawk-Eye cameras that capture the field’s periphery and can trace where the ball crosses the plate in live action. When a player on the field disputes a call, the system’s zone graphic appears on the video board showing where the pitch landed in the strike zone.
MLB’s trial and error with the ABS started in the minor leagues with full automation that originated in the Independent Atlantic League in 2019. A computer called every ball and strike. The robot umpiring generated negative feedback from players, coaches, and even paid spectators. The problem was the slow pace of play and the inability of catchers to frame strikes. After 2024, MLB scrapped the full automation and moved to a standard challenge system that keeps human umpires and allows players to challenge calls in leverage situations.
While not a full year into the Major League season, the ABS is already proving to be a net positive for the game. We are already seeing umpires held accountable for missed calls. It’s hard to believe, but umpires have been improving their correct calls every year since 2008. Even if umpires are getting 90% of calls right, that’s still thousands of missed calls. ABS makes umpires better at their job while taking no more than 15 seconds to review the scoreboard graphic.
It is worth noting that in-game challenges do not slow down the pace of play. Nine-inning baseball games had an average running time of 2 hours and 41 minutes as of May, which is slightly up from two years ago. MLB teams, on average, use around four challenges per game and have a 53% success rate, which likely accounts for the minute uptick.
Undoubtedly, fans relish seeing runners batted in, and there was a noticeable increase in runs. Springtime is generally bad for hitting due to colder weather, which leads to fewer fly balls and home runs. However, in the past five seasons, only one year’s opening month was higher (2023). Scoring is up 4% compared to 2025’s opening months, but it’s only a meager 1.5% compared to last year’s total scoring numbers. With a tighter strike zone and warmer weather, expect more scoring to persist.
One noticeable increase is more walks this year. According to the latest numbers, the walk rate stands at 9.4%, which is a percentage point higher than last season. If the trend continues, it would be the highest walk rate since 1951.
But Batters are more selective, thus they are not swinging as much as they used to. Now they have a deeper understanding of the strike zone and can challenge close pitches. Pitchers are throwing harder than ever, but they are also throwing more pitches and not going deep into games as they adjust to the tighter zone. More walks, more baserunners, and more scoring lead to more fan engagement, which is good for the game.
Of course, there are baseball purists who would rather see the game played without any rule changes or technological innovations. Hall of Famer and baseball purist John Smoltz called ABS a “big success” for MLB, but he warned about full-time automation. Thankfully, we will never be going back to only human umpires, like the NFL will never go back to single-bar face masks. Baseball uses technology and will continue to use it, improving with more data.
Some would assert that “baseball is art, not science.” Fair enough; however, baseball was never meant to be a sport trapped in a time capsule. It’s a game that’s continually modernized, from lowering the mound to racial integration, and that’s helped bring in new fans while keeping the game from standing still. The automated strike zone is the next phase of ensuring professional baseball’s historical prestige.
