By the way, if you gamble with martingale, be careful to predetermine the amount where you stop the game because a time comes when the gambling algorithmic detects that gambler is using martingale strategy and then you do not win any further game and if you do not stop manually, it will lead to a big financial loss.
You can easily tell if you are in a discussion with a new gambler when he is excited to talk about martingale, martingale is a big temptation for newbies because the logic seems sound until they have proven it not.
I've been there, done that, and laughed at myself for being stubborn about using it, but at least have tried it experimented and established the fact that it will not work