Jack Nicklaus pre-turned his head prior to start-up. I just saw some slo-mo of Tiger which shows a gentle turn of his head during his take-away.
Neither should be confused with the head moving off of the ball. I don't know for certain, but I'm betting this does not violate The First Basic Essential - A Stationary Head.
Thanks, Trig,
I appreciate your reply. And I agree that it doesn't violate the stationary head essential.
However, I have time and again rediscovered how important the head positioning is. I think it has a strong correlation with aiming point, hinge action and timing - so I would appreciate every enlightenment of how the head influences the golf stroke.