[glcoach]

After looking at more video of my swing both over a ball and hitting the tire I have concluded that my backswing shoulder turn is quite different over the ball than hitting the tire.

While hitting the tire, my backswing shoulder turn is quite a bit flatter, while over the ball it looks like I'm scrunching my shoulders a bit instead of fully turning them, thus causing the roundhouse move. Problem rectified and positive results so far. We'll see how it goes.