Several good points in this thread, Bill.
I wouldn't disagree with anything said.
The school I subscribe to breaks the
backswing down into takeaway and the
backswing.
It's the old "back and up" idea that
ruled for many years.
In it, you are well near your 90 degrees
by the time the shaft reaches parallel.
That's the finish of the takeaway.
At that point, the upper body starts
its torque.
The correct takeaway has put you into
position to initiate the power loading
sequence, and that position is always
the same: back facing target.
Get jacked for a few extra yards and
turn the shoulders "just a few more
degrees" with this method and you
better know that by doing this you just
took the club more to the inside, and
you hopefully have an idea of how to deal
with it.
I know this probably seems foreign to
you, Bill. You asked if the swing stops
at the conclusion of the shoulder turn.
I'm saying the backswing begins at
the conclusion of the shoulder turn.
Don't throw me out...watch the Tiger
slo mo video.