Honestly if you're looking for odd's martingale roulette could be it and just always bet on one color but make sure you have a hell of a large bankroll to rock it.
Actually had tried to make use of martingale with roulette which only bets with one color then increases 100% if bets lost. I thought making money is easier with martingale with roulette than dice but when theres a color train it did bust up all of my balance.Majority knows that theres no magic or exploiting gambling sites and make money but this is an impossible thing.
The martingale is probably one of the most known and most popular betting methods of all time.
Just for a simple example of the outcomes of using martingale:
Lets say you have 100$ (for simplicity), only doubling 100% on a loss (50 / 50 coin-flip), doing this until you hit 200$ or bust.
You would have a 50% chance of doubling your money (+100$) and 50% chance of losing everything (-100$). This gets a lot worse when you start to look at house edge, hence the house always wins phrase.