Can Robots and Humans Play Baseball Together?

The first recorded, organized game of baseball, which took place in the summer of 1846 at New Jersey’s Elysian Fields, would have been recognizable to today’s fans in its basic format. Each team had nine players, there were four bases, and the teams scored runs by rounding the bases in much the same way they do today. However, in other ways, the version of baseball played in that game was wildly different from the way it is played today. For example, pitchers threw underhand, and fielders didn’t wear gloves.

This points to a paradox at the heart of baseball. Many die-hard fans see it as a sport steeped in tradition and possessing a timeless quality. And while that is certainly true in some regards, one of baseball’s most important traditions is its ability to evolve alongside the world it exists within.

To understand the push and pull of tradition and evolution in baseball, you need look no further than a rule change that took 50 years to be fully implemented throughout the major leagues — the designated hitter. This controversial rule adds an additional player in the lineup who hits but doesn’t play in the field. The extra player usually takes the place of the pitcher in the batting order, as pitchers are traditionally the weakest hitters on any team. The American League introduced the designated hitter, often called the DH, in 1973 in the hopes that it would create more offense and increase attendance.

Not everyone welcomed the change. For example, Pulitzer Prize-winning sportswriter Arthur Daley was wary of the DH, writing in a February 1973 New York Times column that “the ones who are exalted figures in the Hall of Fame are the ones who could do it all.” He concluded the article by predicting that no DH would make it to the Hall of Fame. (This proved to be incorrect — Frank Thomas, who played the majority of his games as a DH, was inducted into the Hall of Fame in 1989, and David Ortiz became the first full-time DH in the Hall of Fame in 2022.)

However, the change was broadly popular with sports fans. In a Gallup public opinion poll conducted in April 1973, 50 percent of sports fans approved of the DH rule, while only 31 percent disapproved. Even so, the National League held out and continued to play without the DH. Interestingly, it was the unprecedented nature of the pandemic-shortened 2020 season that first saw the National League try out the DH. The league permanently installed a DH in 2022, ending a nearly half-century era in which the two leagues played under different rules.

But baseball’s thirst for evolution wasn’t fully quenched by finally resolving the DH controversy. Just last year, Major League Baseball implemented a significant set of rule changes, including instituting a pitch clock that limited the time pitchers could take in between pitches. Baseball games had been getting longer and longer for decades, but the rule change dropped the length of the average game from three hours and four minutes in 2022 to two hours 40 minutes in 2023, putting it back in line with the length of games in the mid-1980s. Just like the DH when it was first introduced in the 1970s, adding the pitch clock was a popular change — the May 2023 Seton Hall Sports Poll showed that 65 percent of fans were in favor of it.

Still, there are substantial questions about the future of the game that remain unresolved. Perhaps the biggest of these unanswered questions is whether the major leagues will begin using an automated system to call balls and strikes, what is often referred to as a “robot umpire.” The technology to do this already exists, and it has been tested in the minor leagues. The technology is called ABS, for Automated Ball-Strike System, and it uses a series of cameras to pinpoint where the baseball crosses home plate. It’s the same technology often used in tennis matches to decide whether a shot was in or out.

The minor leagues have tested two different ways of implementing this technology. The first is to have ABS call every pitch — an operator somewhere in the stadium sees the call from the ABS and then radios it to the home-plate umpire, who wears an earpiece. The second way is for the human umpire to call the pitches, but to then give each team a certain number of challenges. When a coach disagrees with the way a pitch is called, they can use one of these challenges and appeal to the ABS. The MLB already uses video replay and a challenge system for plays in the field, like whether a ball is fair or foul or whether a runner is out or safe on the basepaths, for example.

So, we have the technology for “robots” to call balls and strikes, but does that mean we should use it? To begin to answer that question, it’s worth turning again to what baseball fans think of the potential rule change. Back in 2017, the Seton Hall Sports Poll found very little support for the idea of using robot umpires—75 percent of baseball fans opposed robots calling balls and strikes while only 11 percent of fans supported the idea. But, over time, fans appear to be changing their minds. In the March 2023 poll, 52 percent of fans supported ABS and 28 percent opposed it.

ABS provides the possibility of a consistent strike zone and the elimination of missed calls. There are clearly lots of positives to this, but there are still some quirks to the system that make it less clear whether it would increase the objective fairness of the game. For example, Jayson Stark of The Athletic has reported that the minor league tests have raised questions about whether the strike zone is the same in all ballparks and whether it accurately adjusts the strike zone to players of different heights.

This makes it worth pausing to contemplate what might be lost in the use of this new technology, especially if the ABS system were used to call every pitch. The knowledge that umpires are imperfect humans with their own patterns and tendencies when calling balls and strikes has had a significant impact on how baseball players approach the game. Pitchers seek to stretch the strike zone, catchers try to make balls look like strikes, and hitters learn to adjust to the specific strike zone an umpire is calling in any given game.

Using ABS would eliminate these aspects of baseball, and as long as some of the bugs in the system can be worked out, maybe that’s okay. It’s probably inevitable that this technology will make its way into Major League Baseball in some form — most likely the main questions to be answered are when this will happen and how the system will be implemented. This would represent yet another significant evolution in the sport. It’s a moment for players, fans, coaches, and front-office administrators to carefully consider what they feel makes the game special. It’s also a moment to remember that baseball has been changing and evolving ever since that first recorded game more than 175 years ago.