I regularily play golf with a few friends. One of them has a strange and controversial method of lining up his putts. I believe it to be illegal.
He does the following: Has a look at the putt and takes some practice swings. Then, he grounds the putter behind the ball and while keeping one hand on the grip and not moving the putter, he crouches down behind the putter and lines up the head of the putter with his other hand. Then he takes his stance once again without moving the putter from where he lined it up and takes his stroke.
Is this legal?