The spin parameter is defined as Sp = rω/v and measures the ratio of the rotating ball’s
tangential speed at the equator to its centre-of-mass speed with respect to the air [17]. Here,
r is the ball’s radius and ω is the angular speed. Wind tunnel experiments [2–5] investigated
spin parameters as high as 0.3 or so. Our trajectory analysis work allows for spin parameters
as high as about 1.0 because unlike wind tunnels, we can work with low speeds and high spin
rates just as easily as other combinations of speed and spin