If tiger swung back that far, with hip restriction, it would be his last swing, ever. There are advantages to a shorter back swing, you can accelerate at the ball as fast as you want, that is what I do, on a long backswing you can accelerate too fast and decelerate into the ball. If you remember when tiger started working with butch, he shortened his back swing but did not loose any distance. Daly has a gradual acceleration that very few people would be able to pull off.