Martingale is probability theory used by many casino players. This system involves doubling your bet after each loss. Example: you bet $5 and you lose, you double your bet, $10. You use this system until you win.

Why it doesnt work?

The player who use this system first win but soon lost all money. why? The Casino has a limit of bet, so you can't apply this system till you win the initial bet. The moral of the story is dont bet ever, the Casino always wins!