The purpose of this study was to compare the properties of a pitched-ball rotation, such as the spin rate and direction of the spin axis, which were measured by 2D images with a 3D registration method (2DR), the 3D direct linear transformation method (3DLT), and a Doppler radar measurement system (DRS). The pitched baseball was recorded by using two high-speed cameras (2,000 Hz) and DRS (48,000 Hz). For 2DR and 3DLT, some landmarks on the pitched ball were digitized to calculate the location in 2D and 3D space. For DRS, the 3D spin axis was calculated using equations developed by Nathan (2015). We found that the properties of the fastball were comparable among the three methods, but the properties of pitches that were not fastballs were not always comparable with the others.
Matsuo, Tomoyuki; Nakamoto, Hiroki; and Kageyama, Masahiro
"COMPARISON OF PROPERTIES OF A PITCHED-BALL ROTATION MEASURED BY THREE DIFFERENT METHODS,"
ISBS Proceedings Archive: Vol. 35
, Article 115.
Available at: http://commons.nmu.edu/isbs/vol35/iss1/115