If you are moving your left shoulder down to the ground and then back (away from the target) at the start of the backswing, and you are reverse pivoting, then you are probably tilting the left shoulder down rather than turning the left shoulder perpendicularly around the bent-over spine in a rotatory motion. An easy check - what is happening to your eyeline (line drawn between the eyes) when you perform this move. If your eyeline is tilting upwards (right eye higher than the left eye), then you are tilting the left shoulder and reverse pivoting. The left shoulder must have a more horizontal rotatory movement at the start of the backswing so that your eyes move horizontally as your head rotates a little to the right.

See - http://perfectgolfswingreview.net/Woods-head.jpg

Note that Tiger has moved his head horizontally, and there is no tilting of the head (front bill of his baseball cap turns horizontally). Note that Tiger has got his left shoulder well behind the ball, and that his left upper back slopes upwards to the right. You probably need to have a more horizontal rotation of the left shoulder during the takeaway to get it well behind the ball, and you definitely must avoid tilting the left shoulder downwards. Check in a mirror to see that your left upper back slopes upwards to the right at the end of the backswing - see red outline in this diagram ( http://perfectgolfswingreview.net/Go...versepivot.jpg ) in question number 1 in this section of the review http://perfectgolfswingreview.net/backswing.htm

Jeff,