I've written a lot about the Swivel in the past and have been wrong most of the time. But I agree that Arching the Left Wrist is also Swivel related.

Well I hope you keep up with writing about it Daryl,

I think it's one of the most important things to get right and parts of it is still a mystery to me.

How did for instance Hogan manage to go from bent left wrist at the top to arched at impact? Whenever I arch at the top the club head stays open all the way? I don't get it.

May I ask a favor?
 

May I ask a favor? And this is an appropriate spot to ask. The definition of "swivel". Here is why I ask. At "almost all" points in the swing the motions of the hands (turn-roll) or the wrists (cock-uncock, bent-arched) can be used to describe the motion and alignments- although without brevity it may seem.
BUT.
Out at follow-through when both arms get straight, there is this "swivel" thing- to me, kind of like a universal joint, lets things get-around so they can move freely. I don't care about sequence etc. whatever it takes, a little bending-rollong-cocking in the most free manner.

It may make it harder to explain, by using the wrist/hand terms, but clearer for understanding.

Thanks

The Bear

That might not be a bad thing as long as you slightly less open than the path (drawing the ball).