Blonde Girl Strips A Red Dress At The Roulette Table

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, one unit is added to the next bet, and after each win, one unit is deducted from the next bet. Starting with an initial bet of, say, 10 units, a loss would raise the next bet to 11 units. If this is followed by a win, the next bet would be 10 units. Another win would lower the next bet to 9 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.