Here I look at Mr. X, Miller Barber.
I don't have this swing sequence available for a full image, but here's a .pdf file of Barber in his early days. In fact, this swing seems even more unorthodox and extreme than the swing sequence above.
MILLER BARBER SWING SEQUENCE .PDF
While most people marvel at Barber's 'flying right elbow', I'm more amazed at just how closed his clubface is on the backswing. Then on the downswing, his downswing plane is extremely upright. I heard one poster who referred to it as the 'guillotine plane' when looking at the .pdf swing sequence.
I think Barber had a few things going for him.
1. Incredible hand-eye coordination.
Yes, there are so many ways to hit a golf ball effectively, but I dare anybody to try this and see if they can even come close to hitting the ball well. My guess is that they would fail miserably. That downswing is so upright, that at the last second he winds up dramitically flattening out the plane so he can hit the ball.
2. He had a great work ethic.
As the .pdf file says, he worked extremely hard on the range to keep his swing going.
3. He has a very good pivot.
A must for PGA Tour level ballstriking.
4. He uses pitch elbow.
I think this saves his swing as it allows him to flatten out that extremely steep downswing plane.
I'm guessing in TGM terms he would be known as a 'triple shift' swing plane golfer.
And from looking at the swing, it's no surprise that the author of the .pdf file states that Barber is known for taking extremely steep divots.