The difference with sports betting is that you will have to pay the vigorish, whereas, with casino games, you play on even money bets. For those unfamiliar with the Martingale System, it is a wagering progression where you double your previous wager after you lose so that you will recoup all previous losses in the progression plus an amount of profit equal to the original bet.
It can also be used with sports betting with a few slight modifications. The Martingale System is a betting scheme that is popular for casino betting. How to use the Martingale System in Sports Betting
