The D'Alembert System

French mathematician Jean le Rond D’Alembert introduced his system for winning at gambling in the mid-1700s. It has since become possibly the most famous of all roulette strategies. Its wagering structure has given the D’Alembert system the nickname of the Pyramid.

As with most successful roulette strategies, the D'Alembert system was created for even-money bets, such as red/black or odd/even. The strategy aims to find a balance between winning and losing, based on the assumption that over any time period, there will be an equal number of wins and losses.

Playing Roulette with the D’Alembert Betting System

Choose your wager, which must be above the minimum bet but not so high as to wipe out your bankroll too quickly. Then choose an increment by which the bet will be reduced when won, or increased when the bet is lost.

Reducing a bet follows a certain logic of probability, namely that having just won, your odds of winning again on the next spin is reduced, and therefore you should wager less. The reverse is also true after you lose a bet.

However, as every gambler knows, real outcomes are rarely distributed in this way. Consider it this way; no matter how many times you flip a coin, the odds of it turning up heads is always 50-50.

So in a pure game of chance like roulette, you have a 50-50 chance on every spin of winning an even-money bet, because each spin of the wheel is an independent event unrelated to what came before. Players who believe otherwise fall into the trap of the gambler’s fallacy.

The biggest flaw in this roulette strategy has to do with the game’s house edge. As with all roulette games, the big variables are the 0 and 00 spots, which gives a 5.276 % edge to the house on every spin of the wheel.

The math means that even with D'Alembert, you will lose at least a small portion of your bankroll before winning. Plus, there's always the possibility of a long losing streak, meaning that it may quickly become impossible to continue increasing wagers. Conversely, if you’re on a hot winning streak you won't be able to keep reducing your bets either, as you will eventually reach the table minimum.

There are two advantages to D'Alembert over other roulette strategies. First, bets don't increase as fast as with other systems, so that if you hit a losing streak you can stop playing before losses get too large. The second advantage is that when winning increases your bankroll, you can stop at any time and take the winnings.

Experience has shown that the D'Alembert System results in wins most often when the betting starts with a series of negative spins (losses), followed by a balancing series of positive spins (wins).

Even as the most successful of well-known roulette strategies, the D'Alembert system is no surefire way to win big money. No system, however successful it may be in the short run, can change the odds in your favor. Gambling may be the best example we have of chaos theory, because it functions on unpredictable, random chance.

If you want to use the D’Alembert system on roulette, we suggest experimenting with online roulette games first. Real money online roulette games have low minimum bets ($1 per spin in most cases) that allow you to to practice a roulette strategy without risking a lot of money.