I have used this bowling tool with my students. I have been teaching bowling for over 17 years and just recently tried the ezbowl. The ezbowl allows the student or bowler to get immediate feed back on their release position by watching the different rotations of the ezbowl and the different wobble characteristics of the many different hand releases. I would highly recommend this tool for the beginner and the bowler that wants to perfect his or hers release.