Certainly some times these players with a big lead go on to win, but these are the players I like to go after. Give me an opponent who has had good fortune tossed in his lap all day long. They think they are indestructible. They aren't deluded, drunk even, with the trivial success of doing well when there are 50 people left. That temporary triumph is no triumph at all, especially if, like often happens, they begin to play less sharply than they would if the deck wasn't constantly hitting them in the forehead.
Football offers another good parallel.