MLB Signs on to In-Game Usage of Wearable Pitch-Calling Devices

© Rick Scuteri-USA TODAY Sports

On Tuesday, ESPN’s Buster Olney reported that Major League Baseball is expected to allow players to use wearable signal devices to call pitches this season. Later in the day, the Associated Press reported that the league did indeed approve the use of such devices and sent a five-page memorandum to teams’ general managers, assistant GMs, managers and equipment managers outlining the rules regarding such devices. Known as the PitchCom system, the devices were tested in the minors last season and have made their way around the majors during this year’s spring training, drawing glowing reviews. Aimed at improving the pace of play and countering sign stealing — by both legal and illegal means — their adoption addresses two issues that have been hot-buttons in recent years and have resurfaced this spring. In that light, the league could be doing more to reassure the public that it’s on top of potential abuses of the system.

Created by a company called ProMystic that provides modular technology to mentalists and magicians (!), the PitchCom system consists of a push-button transmitter that fits into a wristband worn by the catcher, and receivers that fit into the padding of the catcher’s helmet and the sweatbands of the caps worn by the pitcher and other fielders. In the transmitter’s nine-button grid, each button corresponds to a given pitch type as well as a location, the latter akin to the familiar three-by-three strike zone grid. From the AP report: “four seam high inside, curve hi middle, slider hi outside, change mid inside, sinker middle, cutter mid out, splitter low inside, knuckle lo middle, two seam low outside.” The other three buttons to the left of the grid are to cancel the selection and to adjust the volume up or down.

Through an encrypted signal, the choice of pitch and location is conveyed, with an audio output that uses a proprietary variant of bone-conduction technology (bypassing the ear canal) and has preprogrammed English and Spanish options, though players can record their own audio. Olney reported that as many as three teammates besides the battery will be allowed to wear receivers so as to aid defensive positioning; generally those will be the middle infielders and the center fielder.

The system, which previously passed safety tests at the University of Massachusetts-Lowell’s baseball Research Center, was tested in the once-and-future California League (officially Low-A West for 2021) in the second half of last season after informal trials in the Cactus League. Via a Sacramento TV news broadcast, here’s a short video from last August that provides a good visual and conceptual introduction:

“The tests were deemed very successful,” PitchCom co-founder John Hankins told The Athletic’s Zach Buchanan in November with regards to the Low-A West tests. “A number of players used it.” Testing in the Arizona Fall League hit a bit of a snag because of that league’s simultaneous rollout of a 17-second pitch clock, with Mets catching prospect Hayden Senger telling Buchanan, “I’m worried a guy is going to shake me off and I’m going to start fumbling with the thing and start putting down a random pitch like, ‘Oh shit,’ instead of thinking about what the batter’s going to hit.”

While MLB may introduce a pitch clock next year, the league does not have one yet, and so the system has worked seamlessly as it’s made its way around the Grapefruit and Cactus Leagues. Google PitchCom and your favorite team and you’ll probably find players giving a thumbs up. A quick sample:

  • From Rays catcher Mike Zunino: “It’s something that’s really going to get the game moving, I think.”
  • From Royals pitcher Zack Greinke: “The feeling in the hat is a piece of cake. Hearing is kind of easy, too. Just figuring it out, I mean, I’ve been looking down for signs my whole life, so you just have to get used to the difference of that.”
  • From Yankees pitcher Luis Severino: “I think it was great. I was a little doubtful at the beginning, but when we started using it, it was really good — with a man on second, too. I would definitely like to use it in my first start [of the regular season]… You know what pitch you’re going to throw right away.”
  • From White Sox manager Tony La Russa, who at 77 years old is representing the old guard: “Very much in favor. I think it speeds the game up… hoping they make it official. But our experience has been a good one.”
  • From White Sox pitcher Dylan Cease, “I like it. It’s nice. … It gives the hitters zero chance of knowing what’s coming… I only have to worry about what I’m doing in terms of if I’m giving away anything with tipping, as opposed to ‘Are they breaking the code?’ like it’s war.”
  • From Twins catcher Ryan Jeffers: “You can do everything with it. Pitch, location, speed, pickoffs, everything. Once you get used to it, it’s really easy.”

Use of the PitchCom system is optional, not mandatory. MLB chief operations and strategy officer Chris Marinak told the AP that “about half” of the 30 teams had expressed interest in using the system, and Players Association executive director Tony Clark stressed that it was optional, writing in a statement, “It was important to ensure the flexibility for players to use — or not use — the technology at their own discretion. The guys on the field are in the best position to make decisions as individuals about whether it’s right for them.”

Even on teams that use the system, some players might be holdouts, and the system will take some getting used to even by those who adopt it. Brewers pitcher Josh Lindblom laid out some of the pros and cons based on his experience using it in a bullpen session:

“It’s like having Siri in your ear. ‘Fastball up and in,’” Lindblom said. “It’s different, so I think there is going to be resistance from some people to use it. What I liked about it was I had the pitch before I came in contact with the rubber.”

…“From a psychological standpoint, I think it could be really beneficial when you hear something and you know what the catcher is thinking before you even get on the mound,” he said. “From an execution standpoint and a conviction standpoint, that’s really big — instead of me standing on the mound and waiting to know what the catcher wants to throw.

“So, from a rhythm and tempo standpoint, it could be really good. I liked it. I could see how some guys wouldn’t like it, and that’s fine.”

Via the AP report, MLB is providing each team with three transmitters, 10 receivers and a charging case for the devices, with a maximum of five receivers and one transmitter used at once, and a charge of $5,000 per item if a club needs to replace a transmitter or receiver. When changing pitchers, a manager will provide a receiver to the replacement pitcher. The receivers and transmitters can be used only on the field; during games, they may not be operated in clubhouses, dugouts or bullpens. Via the memo, “Signals communicated via PitchCom may only be given by the catcher in the game. Signals may not be sent from the dugout, bullpen, a different player in the field, or anywhere else.”

This is the area that might be of concern. While ProMystic claims that the PitchCom system’s industrial grade encryption algorithm is virtually impossible to hack — an assertion that may or may not hold up — it’s unclear from what’s been reported thus far how MLB will police the number of receivers or transmitters in use at a given time. The AP did not report on whether the memo outlined penalties for violations, but in the wake of commissioner Rob Manfred’s edicts and his suspensions of Astros general manager Jeff Luhnow, Astros manager AJ Hinch, and Red Sox manager Alex Cora for their roles in their respective teams’ illegal electronic sign-stealing efforts, presumably anybody found to be involved in such a scheme would face significant and perhaps even severe discipline. That includes players, which wasn’t the case when Manfred penalized Houston and Boston, because they had been granted immunity during the investigations and because the commissioner didn’t want to challenge the union by issuing penalties that had not been collectively bargained. The union has subsequently agreed, and so players can now be suspended without pay or service time when it comes to illegal sign stealing, with no pre-set length of punishment for their infractions.

As if we needed reminders of the morass into which MLB so recently fell, on Monday the Yankees’ YES Network aired an interview with Carlos Beltrán, the lone Astros player named in Manfred’s report. The interview with Michael Kay for the network’s Center Stage show aired shortly before Beltran began his new job as an analyst in the YES booth — his first job in baseball since resigning as the manager of the Mets in January 2020, before he ever managed a game. Within the interview, Beltrán admitted wrongdoing, expressed remorse, and conceded that the Astros’ 2017 World Series win carried “a stain,” but he also deflected some of the blame towards Houston’s front office and said he felt singled out for punishment. You can watch the portion of the interview concerning the sign-stealing stuff here.

All of this comes, meanwhile, as the Yankees are battling in court to prevent the release of a 2017 memo Manfred sent to the team regarding the commissioner’s investigation into allegations of the Yankees’ own sign-stealing efforts that surfaced amid the so-called “Apple Watch” incident involving the Red Sox, which prompted Manfred’s September 15, 2017 warning to all 30 teams. Even given the bad optics of the Yankees’ fight to keep the letter sealed, this is unlikely to be a smoking gun that places what they did on the level of Houston or even Boston. SNY’s Andy Martino, who reported extensively on the Astros, Red Sox, and Yankees’ efforts in the 2021 book Cheated, has noted, “The Yankee letter cannot possibly detail violations after this line-in-the-sand statement from Manfred, because it was written beforehand.”

Back to the PitchCom system, as the quotes from the pitchers and catchers suggest, it’s also aimed at preventing baserunners (and their teammates and coaches) from relaying the catcher’s signal to the batter, which is legal so long as no electronic devices are involved. The implementation of PitchCom will eliminate the need for batteries to change signs with runners on base, cutting down the number of mound visits and, ideally, reducing the amount of dead time in a game.

“We’ve all seen what happens to the flow of the game when runners get on second base,” MLB executive Theo Epstein told The Athletic’s Jayson Stark earlier this week. “Things grind to a halt, because there’s a real cat-and-mouse game – with runners on second trying to figure out the sign sequence and get the pitch and pass it on to the hitter.”

That dead time has been increasing of late. Via Baseball Reference, nine-inning games gained an extra 10 minutes from 2018 to ’21, growing from an even three hours to three hours and 10 minutes. They gained five minutes from 2019 to ’21 even while scoring levels dropped from 4.83 runs per game to 4.53, and the number of plate appearances per game dropped from 38.4 to 37.4. Those gains have happened even with MLB making efforts to improve the pace of play by limiting the number of mound visits per game and trimming the time between innings.

In that regard, greenlighting PitchCom seems like a shot worth taking, especially now, before the introduction of a pitch clock creates another element for batteries to get used to. Yes, we might lament the loss of the pre-pitch ritual of the catcher putting down a certain number of fingers, but that would be a small sacrifice to make if it speeds up a game that has been increasingly slowed. That is, if MLB has the proper safeguards in place to prevent the system’s abuse. Particularly given what we know about the league’s belated efforts to counter sign-stealing, however, that could be a sizable if, and it’s fair to be skeptical about the new technology and to expect both that some teams will remain wary in adopting it, and that some bad actors will attempt to exploit the system to an unfair advantage. Let’s hope that’s not the case, because the game certainly could use the pick-me-ups the PitchCom system offers.

Brooklyn-based Jay Jaffe is a senior writer for FanGraphs, the author of The Cooperstown Casebook (Thomas Dunne Books, 2017) and the creator of the JAWS (Jaffe WAR Score) metric for Hall of Fame analysis. He founded the Futility Infielder website (2001), was a columnist for Baseball Prospectus (2005-2012) and a contributing writer for Sports Illustrated (2012-2018). He has been a recurring guest on MLB Network and a member of the BBWAA since 2011. Follow him on Twitter @jay_jaffe... and Mastodon @jay_jaffe.

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CC AFCmember
10 months ago

Interesting article, thanks!

My first thought at “virtually impossible to hack” was “lol, in other words…possible?” Hackers gonna hack.

Hopefully, it’s at least hard enough that a team would have to go so far out it’s way to hack it that they would set off a bunch of internal alarm bells and cooler heads would prevail.

10 months ago
Reply to  CC AFC

I love the idea a team adds a computer whiz to their payroll just to hack a pitch caller, and then teams start hiring computer whizzes to make “boss buttons” that hide the real pitch

Doug Lampertmember
10 months ago
Reply to  hombremomento

Given how little information needs to be sent, the cypher or code could fairly easily be effectively unbreakable baring stealing the key. You’re basically sending one byte for two button presses. That’s just not enough information to find a pattern unless they do something stupid coding it.

And you don’t need to use a public key/private key system for something like this, so you can be quite a bit more secure than PGP would be with an equal length key.

Now, given that there are multiple devices involved, the key could be stolen, but this gets into spy stuff rather than just hacking.

CC AFCmember
10 months ago
Reply to  Doug Lampert

This sounds way more informed than anything I have to say, which is basically I assume anything is hackable without having any specific knowledge. So what’s the “key?” Is it like a passcode? If so, are you saying someone would have to hack the computer on which the key is stored to acquire it? I swear I will not use this information for nefarious purposes. Probably.

10 months ago
Reply to  CC AFC

Like Doug mentioned, there are different ways to do encryption. If it’s symmetric encryption (the same key is used for both encrypt and decrypt) the key is just a passcode like you said. Longer keys mean it would be harder to guess just by trying all the combinations. The weakness is that the keys need to be stored somewhere.

But you can encrypt without a shared key, public/private key systems work this way. Here’s an example of one algorithm:

So it would be pretty tough to just hack the message. But there’s still things that you could do just listening to the transmission. Maybe a pickoff transmission is shorter in duration than a pitch. Maybe a high fastball has a different signature than a curve ball outside. Those things are easy enough to combat so you wouldn’t expect to see anything. But maybe someone will try.

10 months ago
Reply to  CC AFC

I outlined one method to exploit it below.

10 months ago
Reply to  CC AFC

Teams would likely be a lot more hesitant about doing something that violates the law.

9 months ago
Reply to  CC AFC

Any encryption is technically possible to hack, so that kind of language is legally needed no matter how good it is.