You might think you've never heard about it, but chances are, you've even done this yourself at some point. The martingale betting system is the system in which you double your debt each time you lose. By doing doing so, you not only cover your losses, but gain your initial bet in profit.

This system is designed for casino games that have a close to 50 percent chance of winning, such as certain bets on roulette or blackjack.

In case you already haven't figured it out, the system works like so: make your initial bet, of say, 10$. If you win, simply make the same bet again and again. If you lose, you double the bet, making your next bet $20. the same logic applies, and you either double your bet, or in case you win, you go back to your initial bet. Once you've won, you've covered all losses and gained an additional $10.

Now this works great in theory, nut imagine losing a few times in a row – you'd need a very accommodating bankroll. Furthermore, casinos are not oblivious to this betting system, and they have put table limits in place, making this betting system extremely dependent on luck.

Once luck is factored in, the whole point of a betting system is lost. While this could work for a while, the moment you hit a losing streak would bear a huge dent in your bankroll.

It is advised to try some other betting systems instead, that spread the risk across more bets, making it much safer.