Validation of a live, automatic ball velocity and spin rate finder in tennis

Software designed to quickly and easily calculate the 3-dimensional speed and the spin rate of a tennis ball from high speed video footage from a single camera was validated. The software values were compared to speed values from light gates and spin rate values found by manually tracking the ball logo. The respective ranges were 18–31 ms−1 and 65–165 rad⋅s−1. The speed values had a mean percentage error of 4.47% (1.08 ms−1). The spin rate values had a mean percentage error of 4.14% (4.71 rad⋅s−1).