chbkk
It is my understanding that Homer's on-plane concept is a general concept designed to keep the clubshaft on-plane throughout the
entire swing and not specifically targeted to keeping the clubshaft (or sweetspot) on-plane in the immmediate vicinity of the impact zone. I think that if a golfer gets his clubshaft on-plane throughout his
entire swing, then he has developed an idealised clubhead arc that will in-to-square-to-in and that will enable him to square the clubface at impact.
Here is my idea of an idealised clubshaft on-plane swing - Anthony Kim's swing.
The issue of the clubhead swivelling into impact is a separate issue. I actually think that it happens automatically. Have you watched an Iron Byron machine in action? It has a universal joint that is totally passive. The clubhead swivels automatically to allow the clubface to become square at impact. There is no device in that macahine that
actively causes the clubface to become square at impact.
I think that many golfers (swingers) shank the ball because they have stiff wrists which prevents the automatic release swivel action from happening naturally.
Jeff.