## Roulette strategies

The numerous even-money bets in roulette have inspired many players over the years to attempt to beat the game by using one or more variations of a martingale betting strategy, wherein the gamer doubles the bet after every loss, so that the first win would recover all previous losses, plus win a profit equal to the original bet. The problem with this strategy is that, remembering that past results do not affect the future, it is possible for the player to lose so many times in a row, that the player, doubling and redoubling his bets, either runs out of money or hits the table limit. A large financial loss is certain in the long term if the player continued to employ this strategy. Another strategy is the Fibonacci system, where bets are calculated according to the Fibonacci sequence. Regardless of the specific progression, no such strategy can statistically overcome the casino’s advantage, since the expected value of each allowed bet is negative.

While not a strategy to win money, former Los Angeles Times editor Andrés Martinez described a betting method in his book on Las Vegas titled “24/7″. He called it the “dopey experiment”. The idea is to divide one’s roulette session bankroll into 35 units. This unit is bet on a particular number for 35 consecutive spins. Thus, if the number hits in that time, the gambler wins back the original bankroll and can play subsequent spins with house money. However, there is only a = 60.68% probability of winning within 35 spins (assuming a double-zero wheel with 38 pockets).

### Labouchère system

Main article: Labouchère system

The Labouchère System is a progression betting strategy like the martingale but does not require the gambler to risk his stake as quickly with dramatic double-ups. The Labouchere System involves using a series of numbers in a line to determine the bet amount, following a win or a loss. Typically, the player adds the numbers at the front and end of the line to determine the size of the next bet. When he wins, he crosses out numbers and continues working on the smaller line. If he loses, then he adds his previous bet to the end of the line and continues to work on the longer line. This is a much more flexible progression betting system and there is much room for the player to design his initial line to his own playing preference.

This system is one that is designed so that when the player has won over a third of his bets (less than the expected 18/38), he will win. Whereas the martingale will cause ruin in the event of a long sequence of successive losses, the Labouchère system will cause bet size to grow quickly even where a losing sequence is broken by wins. This occurs because as the player loses, the average bet size in the line increases.

As with all other betting systems, the average value of this system is negative.

### D’Alembert system

The system, also called montant et demontant (from French, meaning upwards and downwards), is often called a pyramid system. It is based on a mathematical equilibrium theory devised by a French mathematician of the same name. Like the martingale, this system is mainly applied to the even-money outside bets, and is favored by players who want to keep the amount of their bets and losses to a minimum. The betting progression is very simple: After each loss, you double the previous bet to the next bet, and after each win, one unit is deducted from the next bet. Starting with an initial bet of, say, 1 units, a loss would raise the next bet to 2 units. If this is followed by a win, the next bet would be 1 units.

This betting system relies on the gambler’s fallacy – that the player is more likely to lose following a win, and more likely win following a loss.[13]

### Other systems

There are numerous other betting systems that rely on this fallacy, or that attempt to follow ‘streaks’ (looking for patterns in randomness), varying bet size accordingly.

Many betting systems are sold online, and may make outlandish promises that the player can ‘beat’ the system by following them. One such system was advertised by Jason Gillon of Rotherham, UK, who claimed you could ‘earn £200 daily’ by following his betting system, described as a ‘loophole’. As the system was advertised in the UK press, it was subject to Advertising Standards Authority regulation, and following a complaint, it was ruled by the ASA that Mr. Gillon had failed to support his claims you could earn £200 daily, and that he had failed to show that there was any loophole.[14]

### Using the dozen bet

There are two versions to this system, single-dozen bets and double-dozen bets. In the single-dozen-bet version, the player uses a progressively incrementing stake list starting from the casino table minimum, to the table maximum. The aim here is to use a single-dozen bet to win before the stake list ends. Many techniques are employed such as: betting on the same dozen to appear after two consecutive appearances, betting on the dozen that has appeared most in the last 15, 9, or 5 spins, betting on the dozen that, after a long absence of 7 or more spins, appears for the first time. The double-dozen bet version uses two dozen bets and half the stake list size of the single-dozen-bet version.

Source: Wikipedia.