I was reviewing Mike LaBauve's One Plane Swing short videos. In one video, he talks about the trail arm/shoulder and how to correct slices and hooks. I never gave my rear shoulder any thought in the swing until now. Perhaps this is why some of hook with S&T?
What I found interesting is when I focus on pushing my trail shoulder and arm DOWN towards the ball in the down swing, I feel I am more on plane with a lot more power. I play in a few hours. I guess I will find out if it works.