Should ESPN Have Committed To the K-Zone For Every Pitch?


ESPN K-Zone shown during a live broadcast of a Cubs and Cardinals game.

Anyone watching Major League Baseball on ESPN this year can now be a better armchair umpire when calling balls and strikes. For every telecast this season, ESPN’s K-Zone Live, or virtual graphic of the strike zone, will be visible during every pitch.

K-Zone is a system developed by Sportsvision Incorporated for ESPN in 2001. It is reported by André Guéziec, the main developer and designer of baseball tracking in K-Zone, that ESPN chose Sportsvision to create this because of its reputation in graphically enhancing sports.

Guéziec  mentions that there are three subsystems that produce the shaded, virtual box during broadcasts. The camera pan-tilt-zoom encoding subsystem calibrates cameras in real time. The measurement subsystem detects the pitch’s flight, measures the stance of the batter, and calculates if the end result is a ball or a strike.

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The trajectory, or measurement component, is perhaps the most important of the three subsystems. Guéziec informs that ball’s flight data is sent to computers running a unique algorithm from three separate cameras around each Major League ballpark. These sensor cameras are typically located down each foul line and above home plate.

The previously mentioned algorithm is called the Kalman filter, invented in 1960 by Rudolph E. Kalman. Consistent with an article published in 2002, the Kalman filter “provides optimal estimates of the system parameters, such as position and velocity, given measurements and knowledge of a systems behaviors.”

All the cameras are important in examining each pitch but an operator is also crucial in making K Zone happen. According to Guéziec, the operator at the stadium uses a computer connected to an outfield camera to establish the top and bottom of the strike zone based on the height and stance of the batter at the plate.  When all comes together, it creates the translucent image you see on your screen at home.

It is important to keep in mind that ESPN has only just recently began displaying a live version K-Zone. Before 2011, this technology was only used by ESPN, along with other broadcast networks, during replays.

ESPN has recently taken the K-Zone a step further and made it three dimensional. This will allow viewers to see exactly how a pitch travels through the strike zone. In addition, there will also be a visual tracker of the ball to give a representation of the ball’s journey from the pitcher’s hand to the catcher’s glove.  The 3D K-Zone is made possible by two tiny cameras fastened to the backstop netting, thus allowing evaluation of both right-and left-handed batters.

As interesting as all this technology is and its ability to help solidify the argument of fan’s at home, umpires will never hear regarding balls and strikes no matter how loud you scream at your TV. This writer personally believes fans will get tired of seeing that little superimposed rectangle on-screen. While it is useful when taking a look at a critical replay or helping viewers understand the strike zone of some batters, this technology may be scoffed at by the time the Midsummer Classic rolls around. A permanent virtual strike zone is better suited for your favorite MLB console video game.