US Patent 9498690 Bat with multiple hitting profiles

A ball bat includes one or more stiffeners configured to provide an attenuating surface that limits the bat barrel's elastic deformation as the barrel deflects radially inwardly as a result of a particularly violent bat to ball collision. The stiffener is spaced apart from the inner surface of the barrel a predetermined distance to form a gap, wherein the gap extends only partially around the inner circumference of the barrel. The presence of the gap extending only partially around the barrel circumference provides multiple hitting profiles around the bat's circumference, with the best performance occurring adjacent the gap, and a reduced performance at all other locations around the bat's circumference.