One bettor won more than a half-million dollars by hitting an insane parlay during Championship Sunday in the NFL. The lucky winner turned their $20 site credit on FanDuel into $579,000 by correctly guessing the winners and exact score of both conference championship games. There's 55 555. There's just 55 555.

A good medium is 3% per play. For example, if you're starting with a bankroll of $100, you should risk $3 on every bet. If you're starting with $1000, you should risk $30 on every bet. Your unit size would be $3 or $30, respectively.