But I was working on Classical Martingale system in several years now. I was trying to answer that big question and was trying to find betting system wich can help me to beat the system. I need to be honest and see that I never find 100% sure way to make that money. I would then probably be on another place right now if I could. But I created my own system which is not 100% surewin, but I think that it can work on long term much like your doubling method.