Many studies on baseball bats have been carried out in the world. And a lot of useful knowledge for development of bats, e.g., coefficient of restitution, trampoline effect and so on, have been obtained. However, effect of clamping conditions on hitting performance has not been clarified yet. Therefore, we have developed an evaluation system for coefficient of restitution on baseball bats using three kinds of clamping devices for bats, that is, “rigid clamp”, “rotating-free clamp”, and “free support”. In this paper, the evaluating system and some examples of experimental results have been reported. We concluded that differences in clamping method of metal baseball bat scarcely affected evaluating results of coefficient of restitution on hitting. The rotating-free clamp is well suited to the system from the viewpoint of the simplicity of experimental operation and adequacy of the data.
