Development of a Baseball Practice Ball Providing Visual Feedback of the Pitch Spin Rate

We developed a baseball pitching practice ball to provide the real-time visual feedback of the spin rate by changing the surface color according to the rotational speed of the pitch. This system eliminated the need for external display devices such as tablets or monitors, thereby reducing the system complexity and cost. Furthermore, it allowed players, coaches, and spectators to simultaneously visually perceive the spin rate, facilitating immediate and intuitive feedback during training.