Roulette wheels have been popular in land casinos since the early nineteenth century. Right from the beginning gamblers have tried to devise strategies that would enable them to get the better of the wheel. The most popular of these strategies is the Martingale doubling strategy. This article describes the strategy, explains its limitations and cautions that it is disastrous for current online roulette games.

The Martingale doubling strategy is designed for the even money payout bets in online roulette. These bets are black/red, even/odd and 1-18/19-36. The player decides his unit bet, say $1 for convenience, and one of the even money bets, say red. The player places $1 on red and every time he loses he doubles the bet on red. When he wins he can start another cycle. Let us see how the Martingale doubling strategy works. The player bets $1 on red and wins. He is paid S2. After deducting his investment of $1 he wins $1. If he loses, then he places $2 on red. His total investment is $3. If he wins on a $2 bet he is paid $4. After deducting his investment of $3 he wins $1. If he loses on a $2 bet, then he places $4 on red. His total investment is $7. If he wins on a $4 bet he is paid $8. After deducting his investment of $7 he wins $1. Hence whenever the losing streak ends with a win the player will win a net amount equal to the original investment.

The Martingale doubling strategy is based on the practical assumption that a losing streak cannot last forever. The player bets on red. The probability of the number being black is 50%. The probability of the number being black twice in a row is 25%. The probability of the number being black thrice in a row is 6.25%. If the player is willing to accept a risk of less than 1% then he should be willing to play seven spins. If he starts with $1 then he will need a bankroll of $64. If black is called seven times in a row he will lose $64. If a red number is called any time within the seven spins he will win $1. This seems a lot of hard work just to win $1.

A reasonable minimum target of win for even a low roller would be $10. The bankroll immediately required shoots up to $640. And if the desired win amount is raised to $50 then the required bankroll will be $3,200. Hence though the Martingale doubling strategy for seven spins gives a 99% plus chance of winning, the amount won will be less than 2% of the bankroll.

In current online roulette games there is a further roadblock, which is a limit imposed on the maximum wager. Playtech imposes a limit of $25, Realtime Gaming imposes a limit of $50, whereas some of the liberal Microgaming online roulette variants impose a limit of $200. Even with this limit, a player wanting to win $10 at the end of the cycle can play only five spins. His chance of winning falls down to less than 97%. The average return to player is based on the mathematics of the game. No strategy can change that. No strategy can guarantee a win.