I was at a teaching seminar for the PGA Stockholm section today and we got to listen to Robert Baker Logicalgolf. It was a very interesting seminar and he said words like compression, planeline, the principles of physics, hitting the inside of the ball etc, and he showed some good drills to work on hip turn and shoulder action with hula hoops. He had been influenced by the yellow book, here´s his webbsite www.logicalgolf.com.