It's a popular drill that coaches prescribe to help players keep their right arm closer to their body at different points of their swing.

When your arms get too far from your body, the hands can get flippy—and the object under your right arm falls out.

It's a drill better done with chips and full wedges than longer clubs, but the goal is the same: Keep the object from falling out from under your right arm as you swing, and your arms stay connected with your body turn through the shot.