Are Robot Umpires Coming to Baseball?

The San Rafael Pacifics, an independent team in the Pacific Association of Professional Baseball Clubs, plays in one of the most old-school baseball stadiums in the country. It holds 960 people on wooden bleacher seats, the scoreboard is updated by hand, and the hot dogs are all-beef and delicious. But, in late July, the organization got a high-tech upgrade. For a two-game series against the Vallejo Admirals, their home plate umpire was a digital pitch tracking system called PITCHf/x.

PITCHf/x was first used in the 2006 Major League Baseball playoffs to analyze pitchers, and the system is now installed in every MLB stadium in the country. It uses three cameras to track the ball’s trajectory and spin and to show where it passes through the strike zone. The tool is accurate within a third of a baseball, and major league teams have been using it for years to track statistics and show pitch trajectory during television broadcasts.

PITCHf/x produces .xml files that are open source. Baseball enthusiasts can download data from any night’s game and analyze it, and there’s a whole online community of amateur analysts that have sprung up around it. Baseball has always been driven by stats and this system gives fans and managers another metric to consider.

But, until the Pacifics let PITCHf/x actually ump a game, it had never made any calls. Now, the computerized system watches the plate when the batter is up and calls balls and strikes. This frees up the human ump to call fair and foul balls and to make calls on runners coming in.

PITCHf/x, which the team affectionately nicknamed robo ump, is a series of cameras each about the size of a GoPro set up around the field. The system officiated two games as part of a fundraiser for the Pat Tilman Foundation organized by former Oakland A’s player Eric Byrnes. Byrnes was the voice of the computer, announcing the calls it made and heckling the players. "As much as the baseball traditionalists want to resist it, it's coming," Byrnes told the Associated Press.

“It’s one of the best umpires we’ve had all year,” says Vinnie Longo, the assistant general manager for the Pacifics. 

Longo had faith in the technology’s accuracy, but he wasn’t sure how players, fans and other umpires were going to react. He says the experiment went incredibly well. Even the saltiest players admitted that they didn’t hate it. Outfielder Zack Pace said he wanted to be the first player kicked out of a game by a robotic umpire, and, according to Long, there's only been blowback from players who struck out. The umpires, including the crew chief Dean Poteet who’s been calling games for 40 years, reportedly thought that the robotic ump improved the game. "Since we've found out more about it, I've had more positive feedback than I'd had negative," Poteet told the AP. The umps liked the clarity, and the fact that it sped up the pace of play. Most surprisingly, the fans liked it, too. Longo says they got excited to see what the computer would call. "I think it'll be accepted, but it will take a while," Pacifics fan Tom Hoffman told the AP.

There’s been talk for almost a decade about how PITCHf/x or other computerized systems could be incorporated into calling games. There has been some worry in the umpire’s union about what it might do to jobs and also some concern about the system’s consistency. But, especially as pitch tracking technology has improved, the biggest hurdle is the emotional one. Players and fans like the possiblity for human error in officiating the game, because it makes it more dynamic. Joe Torre, MLB's chief baseball officer, has said that "the human element always will be part of baseball." Baseball, more than any other sport, is highly tied to tradition. It was the last major sport to bring in instant replay.

There's still strong debate on both sides. Those in favor, like Joseph Stromberg at Vox, say it'll improve the game's accuracy. "It's a better way of calling balls and strikes—and in a sport where a few inches can be the difference between a win and a loss, there's no reason to retain inaccuracy solely for tradition's sake," he writes. Opponents say it takes away from the spirit of the game. "Standardizing the zone would remove a level of interplay between batter, pitcher, catcher, and umpire that many fans find compelling. No longer could a savvy pitcher with pinpoint command annex extra territory off the corners, like Tom Glavine or Mariano Rivera, or learn how to tailor his approach to each umpire’s personalized zone," Ben Lindbergh wrote, for Grantland.

In the first in the two-game series, 536 pitches were thrown, and PITCHf/x missed only one, when a computer overheated. The most interesting moment was when the robo ump made an “umpire’s balk” and was slow to make a call. “It took a minute to make up its mind,” Longo says. “But what are you going to do? Yell at a computer?”

Longo, for one, welcomes our new robot overlords and says he’s interested to see if and when they get picked up by other teams. He suspects it will take a while for the technology to make it to the MLB, because they're slow to change rules that impact all 30 teams, but that it’s hard to argue with a system that works so well.

“This is going to make a stop in independent ball first, because we have fewer regulations,” Longo says. “But the MLB commissioner is paying attention.”

Heather Hansman | | READ MORE

Heather Hansman is a Seattle-based freelancer who writes about science, the environment, tech and people, and how they all interact. Her work has appeared in Outside, Popular Science and Grist.