Roulette strategy - The D’Alembert System

The D'Alembert System is probably the most famous of all the roulette betting systems. Introduced around the mid 1700’s by Jean le Rond D'Alembert the famed mathematician and philosopher of the French enlightenment, the D'Alembert is also known as "The Pyramid", because of the shape of its fluctuating wagering structure.

It was designed for use on simple chances bets (Red/Black), where you alternate with two events, but it can also be used on any even chance bet. The aim of this system is to reach a balance between two chances. In other words, D'Alembert works under the assumption that over a period of time there will be an equal number of "Reds" and "Blacks".

The way the D’Alambert system works is as follows: Each time you lose, you increase your bet, while you decrease your bet each time you win. Exponents of the system argue that it doesn’t matter by what margin you choose to vary your bet, so long as the amount by which you increase and decrease it are the same each time.

The classic D'Alembert progression has also been played with double chance (dozens and columns). As the winning is for 2 pieces plus the bet, the game mechanism is the following: augment the bet with one unit after two bets lost and decrease by one unit after one winning bet. There are numerous variations and many combinations but this one is for sure the most famous.

The D'Alembert system features two main benefits. Firstly you do not increase your bets as rapidly which gives you the chance to stop a session and accept a small to medium loss. Secondly, you can find that your bankroll is positive before a session is complete, this gives you the option to cut short a session with a small win.

This system would work fine but for two things. Firstly, there is a spanner thrown into the works by the presence of one or two zeros on the wheel (depending on whether or not you are playing European or American Roulette). This gives the house either a 2.7% or 5.26% edge respectively and makes the system flawed. Secondly, the possibility of long, long runs of the same result make the practicalities of continually increasing your bet impossible in some circumstances.

Also, you may not always be able to continue reducing your bet if you win. Say for instance you bet the table minimum and win immediately, there is no way for you to decrease your bet other than walking away and not betting at all.

To counteract these weaknesses in the system, some players do the following:

1. They start the progression a few units above the minimum, so they can reduce their bets if they win right away, and thus "store up" their immediate good luck (for example:bet $10, win, bet $9, win, bet $8, win, bet $7 win, bet $6, win, bet $5, lose, bet $6 lose, bet $7 lose, bet $8, lose, bet $9 lose, equals 5 wins and 5 losses, and yet still yields a profit of $5!).

2. They bet a group of bets at each level (for example, at a $5 minimum table, they bet $10, $10, $10, and then if they experience a net win, they reduce to $9, $9, $9 (or a group of five or seven or even nine $9 bets), and if they have a net loss, they increase their bets to $11, $11, 11, (or an even bigger group of $11 bets) to avoid the problem of a long series of losses in a row making the system impractical.

3. They bet the banker bet in baccarat, that actually wins more times than it loses, so the progression doesn''t slowly drift upward too much over time, and then they hope that the fluctuation profits (bet $25 win, bet $20 lose, bet $25 win, bet $20 lose, bet $25 lose, bet $30 win, etc.) more than pay for the 5% banker bet commission charged by the house.

4. (Similar to technique #2) They perform several D''Alembert progressions at the same time, with each progression taking its turn after the other: Therefore (with 8 progressions running at once, and a really unlucky bad start at baccarat, using $5 units) their first 8 losing bets would be $10, $10, $10, $10, $10, $10, $10, $10 (the first bet of each separate progression) instead of a very expensive single progression

With the D'Alembert system, you will win only if the balance has been achieved starting from a series of negative spins. The D'Alembert system works correctly only when a balance has been reached between winning and losing bets.

As with all progressive systems you must be very careful when you use them. The D'Alembert is not as potentially damaging as the Martingale but it can still be the cause of very large losses.

(Thanks to KK for the additional content on counteracting the weaknesses of the system)