Gary has used the Hammer Drill for many years to fix all kinds of issues. It demonstrates how the club and arms relate to the body angle and helps train the correct arm structure. It also helps give the feeling of the correct wrist angles as the sledge hammer gets too heavy to move if it is done incorrectly. The Hammer Drill is good for people who drag or close the club-face and also for arm-rollers. We have just posted a video of Gary showing some students how to do it correctly in Drills.