[spapas82]

For reference; this system is called Martingale https://en.wikipedia.org/wiki/Martingale_(betting_system). It is used for a lot of years; there's even a refernece of it in the Dostoyefsky novel "The Gambler": https://www.cambridge.org/core/books/abs/dostoevsky-in-conte....

Also beyond roulette I've heard of various martingale variations in different gambling games. For example, a common system here in Greece is play martingale on draws on a soccer league (like the World cup or the Euro Cup): Pick the first game and bet on draw (no matter what the teams are). If you win you'll get 3x (that's what the draw usually gives); if you lose, double it and bet draw at the next game. This is a good system if you can afford doubling. I remember a Euro some years ago where there were like 15 games without a draw ; consider that if you started with 1 euro you'd need to bet ~ 32 0000 euros in the 15nth game ...