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Making sense of the video tracking systems

A guide to the new camera-based systems discussed at this weekend's Saberseminar in Boston.

After StatCast is rolled out next year, we'll be able to track how fast shortstops like Xander Bogaerts turn the double play.
After StatCast is rolled out next year, we'll be able to track how fast shortstops like Xander Bogaerts turn the double play.
Mark L. Baer-USA TODAY Sports

You've probably already read a review or two about this year's Saberseminar. Most of them focused on bridging the communication gap between the front office and field personnel, getting them to "buy in" to new concepts like defensive shifting. But maybe the conversation should be about moving from "large-N" studies -- baseball's best practices based on decades of historical results -- to "N=1" studies that focus on improving the play of individuals.

Part of what's making this new approach possible is a plethora of different camera-based player tracking systems. If you're like me, you're having trouble keeping track of how they all work, what they can do, and what they're designed to do. That's why I've compiled this outsider's guide as a basic rundown of what's out there and what's coming.


For the past few years, Sportvision's PITCHf/x system has given sabermetricians detailed information about every pitch thrown in the major leagues. Bloggers used it to think about baseball in new ways, and front offices hired the best of those bloggers, and everyone was happy. Sure, there were rumors of other systems -- Sportvision also developed HITf/x to track batted ball data, for example, and kept most of that data proprietary -- but life was still pretty good.

And then, at this year's Sloan Sports Analytics Conference, MLBAM announced a new tracking system that would provide not only additional pitch data, but also information about batted balls, base running, and fielding. The system didn't have a name at the time, but MLBAM has since christened it StatCast.

How It Works: StatCast is actually a combination of two systems. The first, produced by TrackMan, tracks the trajectory of the ball as it is pitched, hit, and thrown. TrackMan's system is based on Doppler radar and will be discussed more in the next section. The second, which tracks the players, is the brainchild of ChyronHego and uses two camera arrays spaced about 15 meters apart to capture stereoscopic video. This allows StatCast to judge three-dimensional distance to a player similar to the human visual system. Not much is known yet about the process that allows them to produce videos like this, but the combination of video and radar is memory-intensive; terabytes of raw signals will be produced for every game.

How To Get It: Before the 2014 season, StatCast was installed in Citi Field, Miller Park, and Target Field; MLBAM plans to roll it out to the other 27 ballparks by the 2015 season. For now, the only things available are some tantalizing video clips, but MLBAM CEO Bob Bowman said in a March interview, "The goal is to put the product out this year, then get to all 30 parks, then release the data in unvarnished form in 2015."

Potential Use: Like a prospect tearing up the backfields in Spring Training, StatCast is raw but easy to dream on. Teams can evaluate defender's first steps, catcher's arms, and speed on the basepaths. And those are just the raw numbers: How about a true expected BABIP, which uses the expected outcome of a batted ball based on its trajectory, placement, and velocity? Or a stolen base metric that takes into account a runner's lead, the pitch thrown, and the catcher's pop time?

TrackMan Radar

If all that information seems overwhelming, you can also buy just the radar system. Originally developed to track golf swings, TrackMan has been offering their half of the StatCast system (or, at least, something similar) to organizations since 2008. Since then, TrackMan's radar systems have shown up at amateur showcases such as the recent Perfect Game All-American event, where scouts in the ballpark were treated to real-time outputs via a web app.

How It Works: Originally developed to track golf swings, TrackMan's baseball system uses a 3D Doppler radar system collecting 20,000 samples per second. A demonstration at Saberseminar (featuring a left-handed catcher) showed that the system reports pitch speed, revolutions per minute, spin axis (as translated to a clock face), and extension at release point. But Baseball America reports a much larger list of measurements.

How To Get It: By and large, the data aren't available for public consumption yet. But if you're an organization with around $30,000 to spend (maybe a minor-league team or a Division I NCAA program), you can purchase your own and use it to improve your pitchers' breaking balls. Here's an article that explains how different spin rates can produce sinking or rising fastballs, for instance.

Potential Use: The scouting and coaching aspects are important, sure, but that doesn't mean there aren't other uses. Physics of baseball expert Alan Nathan and former MLB pitcher Brian Bannister took TrackMan out for a spin Friday afternoon:


You kind of feel bad for Sportvision. PITCHf/x has been operational in Major League parks since 2007, and then in March MLB gets its seven-year itch and has a fling with some hot new technology. (Don't worry, though, they're not separating: Sportvision and MLB remain partners.)

But Sportvision had an idea something like this was coming, and two weeks after the StatCast announcement baseball analytics specialist Graham Goldbeck was at the SABR Analytics Conference in Phoenix with an announcement of his own. Sportvision's new system, which Goldbeck reluctantly called BIOf/x, is designed to track in-game biomechanics of pitchers and hitters. The approach is similar to the motion-capture systems common in biomechanics labs, but without wearable markers.

How It Works: The system is still under development, so Goldbeck's talks have provided few details. He did confirm that the system uses different cameras with higher frame rates than the standard definition cameras used for PITCHf/x, which capture interlaced 60 Hz video. The higher definition systems capture points in three-dimensional space and time. Goldbeck implied that the traditional motion-capture systems were more accurate, but because no sensors are required, the system can be used to measure mechanics in real situations, when fatigue and stress may change how players behave.

How To Get It: The system is not yet available on the market, so the data aren't public yet either. Sportvision does plan to sell the systems to individual clubs, so even once the system gains some acceptance, the data will most likely be kept under wraps, especially if it proves useful in highlighting the type of poor mechanics that can lead to injuries.

Potential Use: Goldbeck showed some example data captured in September 2013 at the Oakland Coliseum and in October 2013 at the Arizona Fall League. The parameters collected for pitchers included location of plant foot, and the location of the shoulder, elbow, and hand at release; for batters, BIOf/x captured swing plane, the locations of the hands and tip of bat at point of contact, and the locations of the back and front foot. Goldbeck showed how the swing plane data could be used to show how well a hitter timed a pitch, and whether he got the sweet spot of the bat on it.

All this extra information will drastically change the way front offices make decisions, allowing them to focus more on the process that led a player to make a certain play, rather than the actual result of the play itself. But aspiring saberists might be in for disappointment: Boston Red Sox senior baseball analyst Tom Tippett told attendees he wished the PITCHf/x data hadn't been released to the public, as the quality research done by amateurs bridged the gap between teams who invested heavily in leveraging the new technology and those who worked off what was publicly available*. As the cost of these systems rise -- and as teams foot the bill for more specialized systems -- the gap between the insiders and the outsiders will continue to grow.

* - I admit it's fun to imagine a team that used PITCHf/x data dealing with a team that didn't. How fun would those transactions be?

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Bryan Cole is a featured writer for Beyond the Box Score, and is lobbying to add a baseball trivia quiz to next year's Saberseminar. You can follow him on Twitter at @Doctor_Bryan.