But as Poker Player say, the risk is the variance, make 100 bets, with 50% chance of winning, if most of them lose then double the bet, and that way you can win in the long run against the house.
Here you are describing the Martingale and it sounds like I have seen you in some thread also talking about this. It is basically a bad method because by doubling the bet you increase the risk exponentially to win only the initial bet on net.