The effect of surface geometry on the trajectory of a soccer ball

Two different evaluation techniques were used to assess the effect of surface geometry on the trajectory of a soccer ball. High-speed video was used to observe five professional players taking free kicks with four different soccer balls. Initial conditions were assessed and the average initial speed of the kick and spin was approximately 24 m/s and 106 radians/s. It was found that players could induce up to 50% more spin with balls that had a rougher surface than with other balls. The trajectory of these four balls thrown at different speeds and spin rates throughout the gym was recorded using a custom-made throwing device and high-speed video cameras, and their action and bounce coefficients were estimated. It was found that balls with more panels had higher bounce rates. The action rate results showed a high degree of dispersion, making it difficult to distinguish between balls. Using the results in the trajectory prediction program, it was found that increasing the number of panels from 14 to 32 could significantly increase the position of the free-kick spin from a distance of 20 meters by more than 1 meter.