There’s a chorus of indignation each time it occurs — when the home plate umpire makes a seemingly egregious ball or strike decision. That chorus eventually rises to a single plea, echoed over social media channels and into the heads of Major League Baseball’s top decision-makers: robot umpires now.

At face value, it has merit. The opportunity for nary a missed call at the plate is enticing, especially after a blow-up incident, such as when Orioles slugger Ryan O’Hearn laid into umpire Alex Tosi this month for an inconsistent strike zone.

But, even when frustration boils over in that way, the players within Baltimore’s clubhouse are resistant to the idea of robot umpires — or, as MLB calls it, a full automated ball-strike system (ABS for short). There are more supporters for a challenge system, in which a pitcher or hitter can use one of the team’s three challenges per game to call for a replay review of a pitch.

Either option has its faults. And, in a clubhouse with two players who could play a direct role in deciding whether the challenge system or robot umpires enter the highest level of the game, their opinions matter.

Whether those opinions are heeded is another debate. MLB’s competition committee is composed of six owners, four players and one umpire. Right-hander Corbin Burnes is on the committee, and left-hander Cole Irvin is an alternate in case of need. Both are well versed in the arguments for and against introducing a challenge system or full ABS to baseball, and Irvin has firsthand experience pitching with it when he spent time in Triple-A last year.

Because the players are outnumbered by the owners on the competition committee, Burnes said, “they don’t really listen to what we have to say. A lot of things we say they don’t listen to, so it’s kind of like talking to a wall.”

But it’s their careers that will be most directly impacted by the implementation of technology into a strike zone that has been, at its core, a human element of professional baseball for nearly 150 years. Even if it can rankle players and fans alike on occasion.

“The Hawk-Eye system, the system they’re using in the minor leagues, they need to make sure that’s perfected to where all the players can agree on it, to where umpires can agree on it,” Irvin said, “because those are the two factors that are taking that information and you’re living on that. Like, that’s going to affect players’ careers.”

The debate will go on and on, and it heats up each time a missed call leaves a batter to shake his head — or worse — and a fan base takes to social media to call once more for robots.

The concern with robots

As Irvin rose and fell between the majors and Triple-A last year, he thrice pitched with the full ABS system working behind the plate. The robot umps, first implemented for select games at that level in 2022, rely on the same Hawk-Eye system used in tennis (using high-speed video cameras that triangulate the flight of the ball) to relay to the umpire whether it was a ball or strike; then the umpire signals the call.

Each of those three games was jarring for Irvin, however, when he found the strike zone kept changing. There was no consistency between starts — the same complaint many people have with human umpires.

The first time, Irvin received strike calls near the shins of batters — well below the traditional bottom of the zone that generally aligns with a hitter’s knee. If a pitch nicked any bit of that zone, even if the majority of the ball appeared low, it was a strike. Meanwhile, Irvin said, the top of the zone was hardly called.

His next start with ABS, Irvin received more strikes at the top of the zone, as well as more strikes side to side. And, in his final start, Irvin noticed that the strike zone was based on a batter’s stride. A hitter started tall, but once he took his step forward and crouched more, the zone shifted mid-windup.

“It was a different zone than he technically started with,” Irvin said. “The automated strike zone would be ideal, but that system is far from even being ready. It’s a challenge to figure out where the zone is; it’s a challenge to figure out — is it at the leg lift? Is it when the leg lands? Where do you time that up from a computer side of things? There’s too much in that to really rely on that system. Where’s the bottom, where’s the top?”

That’s a central concern when it comes to implementing robotic umpires, and it’s one Burnes, in his role as a competition committee member, hears frequently from minor leaguers experiencing full ABS. The strike zone changes from hitter to hitter.

“The main thing we hear is there’s still so many flaws with it,” Burnes said. “You don’t know what the actual shape of the strike zone is. It’s tough to calculate for each hitter. Stuff that I don’t really know if it can be resolved as far as having to change the height of the strike zone every time a guy gets up, a guy stands tall, and when he strides, he shrinks down. So there’s always a change in strike zone.”

Plus, a full ABS system would take much of the defensive role of a catcher out of the game. Adley Rutschman and James McCann, Baltimore’s backstops, can steal strikes by framing a pitch well. The position as it’s known would change completely.

Teams would favor hitting-first catchers, left-hander Danny Coulombe surmised. First baseman Ryan Mountcastle said it would take away “the art of framing pitches” and, by extension, make the catching position less valuable in a way. Rutschman said he assumes “you would care less about how you caught the ball.”

That would be a loss, another unique set of skills taken away from the sport.

But, when it comes to understanding the variations of a strike zone, there is a counterpoint, of course. Each umpire has a slightly different zone each night. Isn’t that variation not unlike the variation Irvin and others experience with a robot?

It goes back to the “human element” so many Orioles value in baseball.

“Each umpire is kind of unique, just like each player is unique,” Burnes said. “But I can understand where the frustration comes, big pitch in the game and there’s a call a guy may not like. So, personally I’m more the status quo, but just what I’ve heard around the game and my job on the committee is to do what the overwhelming majority [wants] and what we think is best for the game. I think the challenge system is probably the most favored thing.”

The willingness to use a challenge system

McCann is quick to point out that, if a replay review system had been in place on June 2, 2010, baseball would have another perfect game in its history book.

That was when the Detroit Tigers’ Armando Galarraga should have completed a perfect game yet first base umpire Jim Joyce incorrectly ruled the 27th hitter beat the throw to first on an infield grounder. It was a gut punch for Galarraga, who stepped back on the mound and finished what he called “the first 28-out perfect game.” Joyce apologized. A review would have fixed the mistake and corrected history.

McCann views a challenge system for balls and strikes similar to the challenge system introduced on the bases.

“As a baseball traditionalist, there’s always been the human element of the game,” McCann said. “I think that the challenge system on the bases is great. There would be an extra perfect game in the history of baseball if we would’ve had that back then. For me, it’s more of a checks and balances than the end all, be all.”

With only three challenges a game, they would likely be reserved for big moments — the bases-loaded strike three that might’ve been ball four.

After O’Hearn was ejected this month for his comments to Tosi, he said a challenge system could be the answer. “A lot of hitters know when they’re getting screwed it seems like,” O’Hearn said, “and it would be cool to be able to challenge it.”

Most others in the Orioles clubhouse agreed.

“Just from my short experience down in Triple-A last year, it was quick and I sort of enjoyed it,” said Mountcastle, who noted he didn’t use any challenges because he was “too scared to mess it up for the guys.”

Burnes said: “From what I’ve heard from hitters, pitchers, a lot of catchers, the full ABS is just not the route we want to go. You take a lot of it out of the umpire’s hands then. The umpires don’t want the ABS. So I think the challenge system is something I think eventually will come about, just like we have replays. You can replay certain calls if you think it should be overturned.”

But some of the same concerns that revolve around a full ABS system apply to the challenge system — after all, it’s the same technology in a pared down form. An umpire establishes his zone each day, and the teams could play eight full innings with an understanding of that zone.

Then, in the ninth, a challenge might introduce a different zone. The ABS system could decipher that a ball just below the letters is a strike, even if the umpire hadn’t called anything above the belt all day.

“A pitch that hasn’t been called a strike all night is suddenly a strike?” McCann said. “I don’t know.”

The strike zone isn’t so easily defined

When a fan turns on a game, there’s a box superimposed above the plate. It gives a rough representation of what a strike zone is — emphasis on rough — and it’s part of the reason there’s a push for robot umpires from viewers.

The major league rule book defines the strike zone as “the area over home plate from the midpoint between a batter’s shoulders and the top of the uniform pants — when the batter is in his stance and prepared to swing at a pitched ball — and a point just below the kneecap.”

In reality, that strike zone is more frequently called at the bottom of the letters, higher than the belt. It’s not a rectangle, either.

“It’s really more of an oval,” Irvin said. “That [the TV strike zone] isn’t a perfect representation of where the zone is.”

The strike zone, then, is what an umpire perceives it to be, not what social media users decide or the television box that doesn’t move to reflect a batter’s stride or the variations in height.

“I think that’s what’s caused a lot of the uproar, and fans, people around baseball, you turn on the MASN network and there’s a box up there and it’s technically not right,” Burnes said. “That’s where a lot of the uproar comes, from social media.”

Added McCann: “Someone who’s very matter of fact will say the rule book says, ‘This is the strike zone.’ But if you go look at the way umpires call a strike zone, it’s not the way the rule book indicates it should be, right? And that’s the human element.”

They are resistant to removing that human element from a game that has relied on it since the 1800s. There’s more openness for a challenge system, but robots are a nonstarter for those whose opinions carry weight.