Gambling in itself is bad enough even when the game is square (honest); but your professional gambler never plays the game that way. He is an expert with cards. His seemingly innocent shuffle of the pack gives him a full knowledge of where every card is located. He deals you a hand good enough to induce you to make dangerously high bets, but not high enough to win. He lures his victim by small winnings to destruction in the end. He uses cards so cleverly marked on the back that he can read the values of your hand as well as if he were looking over your shoulder, and governs his play accordingly.
Harry Houdini, The Right Way to do Wrong, 1906.