If you want to talk about “natural” swings you have to start with Jimmy Bruen. There is no way anyone would teach such a backswing, and you would have to think that if Jimmy didn’t already hit the ball well before a more conventional teacher got a hold of him the motion would never have been allowed to stay that way. That’s good news for us, because we can now study one of the most interesting swings of all time. It’s too bad that Jimmy didn’t have a chance to play more against the best players as a professional, but my guess is that he would have had a fine career, as evidenced by the fact that he is only one of two men (Jose Maria Olazabal being the other) who won the British Boys, the British Amateur, and was low amateur in the British Open.
His swing is really defined by the lack of right arm, hand and wrist rotation in the backswing, which caused the right forearm to point directly away from his head at the top of the swing with the shaft pointing almost sideways across the line, setting up a massive “helicopter” move where the clubhead wheels around to find the downswing plane while Jimmy’s pivot stays in continuous motion. If you look at the swing from left arm parallel in the downswing to the finish you would never guess that his form in the backswing was anything but conventional. The additional stretching of the muscles in the upper trunk caused by this action is no doubt part of the reason he hit the ball so far. It may have required exquisite timing (golf always does) but when you see it in action you might wish you could swing like that, as it does not look like it required any conscious thought to build the technique. I compare the swing to Eamon Darcy and Jim Furyk, but the more I think about it I see it as a less conventional Fred Couples, where the club floats to the top any old way then is led down by the body with a side arm throwing motion right out of Hogan.