[BerntR]

There is a fundamental problem with 1-L 18 in combination with a plane shift.

Question: How do you change the plane angle from turned shoulder to elbow plane while you at all times drag and drive towards the same plane line?

Answer: You do it by applying additional forces that is way off plane:
a) a PP#2 pressure that is backwards and downwards at the start of the plane shift. And the opposite direction by the end.
b) a torque through the hands that drives the clubhed even further down than the hands, per a) and later stops it from rotating even flatter.

In other words: Steering. There will be two steering components: One that consists of the club as a whole being moved on a curved plane. The second being that the club itself will have to be rotated from one plane angle to the next.

The physicists amongst us could then proceed to argue that, when you try to rotate a rotating object with around 90* angle to the first rotation, you get a coriolis acceleration that works in the 3rd dimension. If it has any real impact it will work towards rotating the plane line on the ground.

Whether you're a fysisist or not: Rotating the swing plane and rotating the club your're swinging with around two different axes for a while - before you stop the plane bending and the secondary club rotation - it is not the easiest thing to do. Not in theory anywway. But that's the implication of 1-L 18 combined with plane shifting.

The Haney plane thing can be made basically steering free. The club itself will have a constant plane angle so you don't need to worry about additional club rotation. If you simply add a vertical component to a swing that would othervise pass the impact zone high above the ball, you can have a basically compensation free stroke. If from mother earth gravity doesn't do the whole vertical part for you, you will have to torque the club head towards the ground as you start lowering your swing plane. If you do it in a certain way you can keep your clubhead on the same plane angle throughout the stroke. Like a frisbee that spins nice and clean as it approaches the ground. But your hands will be above the clubhed plane most of the time and cross to the underside at some point prior to impact.


Of course, all of this is theory. But so is 1-L. There may be physiological reasons that speaks for a certain amount of steering and I don't know whether that will be in favor of TGM plane shift or Haney parallel planes.