Play roulette ...bet on colors, play red AND black at the same time ... put a small bet on zero (just in case ...)
not shure the casino accept this ...
Start the first round - $50 Black
If black win; second round - $50 Black
If black loose; second round - $100 Black
If black win; third round - $50 Black
If black loose; third round - $150 Black
Repeat