Richard Marcus hunger to win big likely set in when he moved to Las Vegas and found himself homeless. Soon he found a job as a blackjack and baccarat dealer and his interest in the games began to take the form of ways to beat them. His primary con almost sounds ludicrous on its surface, especially in terms of how brazen it is. Nethertheless it worked!
His scam, called past posting, involved waging low amounts, and then if he won, discretely change low value chips for higher value ones. This could transform wins in the hundreds, to $10,000+ wins in an instant, and remarkably for the longest time this sleight of hand went unnoticed.
He was eventually caught, but not convicted and is thought to have won several million dollars all in all. He now advises casinos on how to avoid loses to those with similar ideas!