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ERIC Number: EJ1142622
Record Type: Journal
Publication Date: 2017-Mar
Pages: 3
Abstractor: ERIC
ISSN: ISSN-0031-921X
Statcast and the Baseball Trajectory Calculator
Kagan, David; Nathan, Alan M.
Physics Teacher, v55 n3 134-136 Mar 2017
Baseball's flirtation with technology began in 2005 when PITCHf/x® by Sportvision started to be installed in major league ballparks. Every stadium had the system operational by 2007. Since then, the trajectories of over six million pitches have been measured to within about half an inch using three 60-Hz video cameras to track the position of the ball. In the 2015 season that modest flirtation exploded into a total technology love affair with the debut of Statcast. Instead of just tracking each pitch, Statcast follows everything on the field all the time: the pitched and batted baseball as well as all the players. This new system uses Doppler radar supplied by Trackman to follow the ball and video tracking by ChyronHego to monitor the players. The dual technologies are needed because Doppler radar is ideal for tracking the ball with typical speeds between 30 and 120 mph. This is roughly the same speed range used by law enforcement radar to measure the speed of your car. Video doesn't work to track the ball because it is so small that the variations in the background of the camera image create a signal-to-noise issue. Radar is a poor choice to measure the motion of players because their speeds rarely exceed 20 mph, resulting in too small a Doppler shift to measure above the noise. Since players move against a constant green turf background, they can easily be followed within a video. While Major League Baseball made the decision early on to allow free access to PITCHf/x data, they unfortunately have been less forthcoming with Statcast information, which is more challenging to share because of the huge data sets. We know of only two publicly available sources: MLB's Statcast Leaderboard and Baseball Savant. The former has a limited selection of information but is easy to use. The latter contains a far more complete data set, but can be more challenging to navigate. We intend to introduce physics teachers (and hopefully, in turn, their students) to the Statcast data set and a powerful spreadsheet called the "Trajectory Calculator." The potential investigations of the national pastime that these tools allow are far too broad to enumerate here. So, we'll just settle for the basic application described below.
American Association of Physics Teachers. One Physics Ellipse, College Park, MD 20740. Tel: 301-209-3300; Fax: 301-209-0845; e-mail:; Web site:
Publication Type: Journal Articles; Reports - Descriptive
Education Level: N/A
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A
Grant or Contract Numbers: N/A