US Patent 7717813 Bases for baseball and softball

A base for baseball or softball including a bottom surface wherein at least a portion of the bottom surface includes a prepared surface having a higher coefficient of friction than the surface in its unprepared state and wherein the base will move from its resting position when a human body applies a lateral force thereto, the force being low enough to avoid substantial injury to the human body, but will remain in position when a force applied to the base includes a downward force component that is substantial in comparison to the lateral force component.