One of the greatest sports figures of all time at last breaks his silence in a memoir as unique as the man himself. Number 4. It is just about the most common number in hockey, but invoke that number and you can only be talking about one player -- the man often referred to as the greatest ever to play the game: Bobby Orr.  From 1966 through the mid-70s he could change a game just by stepping on the ice.  Orr could do things that others simply couldn’t, and while teammates