Why is it that when viewing the pros on YouTube who are swinging the Stack and Tilt way, look like they are swinging with their arms? I thought that the arms are just there for the ride. I noticed the same thing with Weir at the Memorial. (too bad his putting let him down. He could have won.)
Keeping my arms pinned to the body works well for me. Sometimes, I will hit it fat if I try to increase the speed of the downward swing by putting some arm strength into it. I was just trying to find some untapped power...
Once in awhile, I will hit a great drive. Then, I try to figure out how I did it.