I struggled for years without improvement going to mechanical teachers, and watching mechanics-based videos and books by Leadbetter, McLean, Mann and several Tour Pros. I could never understand how teaching to hit a stationary golf ball could be more complex than teaching to hit a 90 mph fastball. The answer is, it's not. The golf teaching industry has looked at the swing and said, "we see how it moves". So that's the way they teach. In a visual mode by positions. But the golf swing is really controlled by feedback (feel). You can't see your own positions. I finally drastically improved after I read Ernest Jones' 'Swing the Clubhead'. Flick's 'On Golf' is a progression of Jones' concept and gives a more indepth look at how to attain and keep a feel-based swing. We are not machines. We cannot accurately repeat positions. But we can repeat feel and Jim Flick understands that.