System and method for determining spin measurements using ball marking

A sports ball configured to enhance detection of spin properties by a radar, comprising:

• a spherical body comprising an exterior surface having a first reflectivity with respect to a radiation generated by the radar to be used in detecting spin of the sports ball and being semi-transparent with respect to the radiation generated by the radar;
• and
• a first marker having a second reflectivity with respect to the radiation generated by the radar to be used in detecting spin of the sports ball, the second reflectivity being different from the first reflectivity, the first marker being embedded within the sports ball on an interior surface of the sports ball, wherein the radiation generated by the radar can penetrate the semi-transparent exterior surface of the sports ball to reach the first marker, the first marker extending along a path crossing every great circle extending around the sports ball, wherein the first marker is formed as at least three strips, a first strip extending along a first great circle of the interior surface, a second strip extending along a second great circle of the interior surface, and a third strip extending along a third great circle of the interior surface, wherein the first, second and third great circles are not coextensive and meet at a location on the interior surface, wherein, on a first hemisphere of the interior surface having the location at its center, the first strip extends in a first direction away from the location toward a second hemisphere, the second strip extends in a second direction away from the location toward the second hemisphere, and the third strip extends in a third direction away from the location toward the second hemisphere,
• wherein a width of each of the first, second and third strips is selected to be between 1/20 to ½ of a wavelength of the radiation used by the radar to be used in tracking the sports ball.