I really, really, really, really need to focus and keep my eyes on the ball. When I do that, I'm not 5/8ths bad! But I don't do that reliably. That's a focus for 2015.

PM gave me a book, The Square-to-Square Golf Swing, a 1970 Golf Digest book from the era of hand-drawn diagrams. A good, basic, refresher on the basics and physics of what matters. At the time, this book was revolutionary, just as Ben Hogan's Five Lessons: The Modern Fundamentals of Golf was for its time 20 years earlier. The Square-to-Square update focused on changes needed to recognize the then-new golf technology of stiff club shafts that would not only not bend, but not twist - club shafts could finally reliably hold a club face perpendicular to a swing plane.

With this new technology came a need to re-address Hogan's earlier investigations and the result was a focus on re-training one's leading arm (left for right-handed golfers) to be dominant and the trailing arm submissive. The right arm becomes unnecessary for "steering" the swing to counteract bendy and twisty club shafts and in fact becomes an impediment for most golfers that should be dampened. This would explain why one-armed golfers can be successful - the trailing arm does not a lot more than center the swing along the vertical plane of the torso and that can be accommodated even without that arm. The club- and ball-testers used by manufacturers don't need to simulate two arms in most cases, and focus on the "leading" arm, so why should a human golf swing be the same except for habit?

That was the "Model Method for the Modern Player" 45 years ago anyway and for most of us duffers the theory and practice is still sounder than anything we can make up ourselves today.