Why can’t people go to the casino playing roulette and bet on black, and if they lose, double what they lost and bet on black again until they win?

Question

If you bet $100, your odds of winning are around 50% and if you lose, bet $200, and so on and so forth until you win, and then cash out with a guaranteed profit. Assuming odds of black are 47.37% as per American roulette, your odds of not winning a single one after 6 tries are 0.02125 (I think) and decrease exponentially after each subsequent try.

In: 93

Answer 1

The house edge is just over 5% in roulette. Use whatever strategy you wish but on a $100 bet you will lose an average of $5 per spin over a long run.