MLB approves four wearables for on-field use in 2016

The Associated Press reported yesterday that Major League Baseball's playing rules committee has approved four wearable devices for on-field use during the 2016 season.

Two of the systems -- Motus Global's motusTHROW, which tracks workload and stress for pitchers, and Zephyr's BioHarness, a monitoring system that combines heart rate, respiration, and accelerometry -- were approved for in-game use. Two bat sensor systems -- Diamond Kinetics' SwingTracker and Easton's Power Sensor Motion by Blast -- were approved for on-field use during events like batting practice, but not for use in-game. The approval also extends to minor-league games, according to Motus Global CEO Joe Nolan.

MLB vice president for communications Michael Teevan said data cannot be collected from the devices during the game but must be stored on the devices until after the game has ended. This means that, although all of these systems could in theory connect with apps on the newly-approved iPads, coaches won't be able to use information like Motus Global's workload score to determine whether or not to take out a pitcher. (To ensure this, the iPads available in the dugout will not have Bluetooth wireless receivers.)

MLB Players Association, the union representing professional baseball players, worked with the playing rules committee to develop rules to protect the privacy of its members. Teevan also said that players will be able to access their own data. However, to protect players' privacy, the data will not be available to the public or to other teams. MLBPA had not returned requests for comment at time of publication.

Teams will have easy access to the plethora of metrics produced by these systems, relying in part on the expertise of the device manufacturers to help them interpret the new on-field data.

"The power of our system is in our ability to make sense of the data and provide actionable information," Nolan said. Our work with leading medical partners sets Motus apart."

But at least some of the device manufacturers, including Diamond Kinetics, will also give teams access to more in-depth versions of the data. This will allow teams to develop their own metrics.

"We have worked with a number of teams through the fall instructional league and this spring to enable them to not only use our real time metrics but via API provide them access to a much more broad data set that can be used within their proprietary systems and databases," Diamond Kinetics CEO CJ Handron said.

The companies behind the sensors were naturally excited to share the news.

"We're pleased that there continues to be momentum building toward the use of real time data to help inform players and coaches," Handron said.

About the Devices

For those unfamiliar with the technologies, I thought I would close by giving a quick overview of each device. I've also included my guess as to how likely a fan is to see them on the field this summer, based on where the device will be used and how it will be worn.

• Diamond Kinetics' SwingTracker was first released in December 2014 and contains a triaxial accelerometer and triaxial gyroscope. It attaches to the end of the bat through a flexible strap and tracks a number of metrics related to swing power, speed, control, and quickness. The Pittsburgh-based startup has worked with MLB organizations before this announcement but has not named any specific clients.

  On-field sighting: The bat sensors, of course, haven't been approved for in-game use, so the only way to see them is in person during batting practice. At least they have a ring of bright green, so they might be easier to spot. Medium probability.

• Originally developed by Blast Motion, the Easton Power Sensor Motion by Blast was renamed after a partnership deal was reached with the bat manufacturer last summer. Easton and Blast claim their sensor's advantage comes from "tactical-grade" technology, including more precise inertial accelerometers, gyroscopes, and magnetometers, as well as more processing power. Easton and Blast have not discussed any relationships with professional teams but have demonstrated the product at the last two Little League World Series. (Easton is the official equipment sponsor of the event.)

  On-field sighting: Like Diamond Kinetics, the Easton sensors will be allowed only during batting practice and other training sessions. Unlike Diamond Kinetics, though, the Easton sensor is white and held in place by a clear plastic bat attachment. You're going to have to be right on top of this thing to see it. Low probability.

• Motus Global's motusTHROW system is the successor to last year's mThrow sleeve. Labeled "the sleeve that could save baseball" when it was first announced, the heart of the device is a high-range accelerometer and a high-range gyroscope. The system reports a number of joint kinematics such as arm angle and pitch count and estimates workload based on the torque sensed at the elbow. Although the newest version of the sensor can also be clipped to a glove to track hitting metrics as well, MLB in-game approval was extended only to the sleeve for now. The device was first tested at the 2014 fall instructional league and was provisionally approved for use during the 2015 season.

  In-game sighting: Once the weather warms up and long-sleeve shirts start to disappear, expect to see the compression sleeve on throwing arms across the league -- and pitchers constantly fidgeting with it between pitches. High probability.

• The Zephyr BioHarness contains an accelerometer, ECG sensor, and temperature sensor. Metrics reported include heart rate variability, respiration rate, activity, and calories burned. Russell Martin was first seen wearing a BioHarness compression shirt in March of 2014; a number of his Pirates teammates adopted the practice over that season. A version is available on Amazon for $630.

  In-game sighting: The device is worn on a strap or compression shirt, and baseball uniforms aren't as form-fitting as soccer jerseys. So unless someone's jersey gets ripped off in a postgame celebration or a brawl, you probably won't see this one. Low probability.

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Bryan Cole is a featured writer for Beyond the Box Score and is really just geeking out over this. You can follow him on Twitter at @Doctor_Bryan.