He already had the world's best rhythm and balance. Stands to reason he could do this.
It would be a good laugh to see some current top golfer mimic that act of Fred’s sometime, teeing off on some hole in a PGA tournament.
Current teaching...”You must keep your head still”....and your arms, hips, wrists, knees, must hit the exact positions and angles to hit a solid shot.
Not in Fred’s world...