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D'Alembert System

Online Roulette Guide

A gentle negative progression system for roulette.
The closest you’ll get to “card counting”.

Best Casinos for the D'Alembert

Please make sure you read these notes before you use this system. There is also a reverse variation of this system: the Reverse D’Alembert.

Quick Guide to the D’Alembert System:

  1. Increase your bet by 1 if you lose
  2. Decrease your bet by 1 if you win

If you want to increase you r risk, you can always increase these numbers, but the overall theory remains the same. Increase after a loss and decrease after a win, and always keep to your starting bet level (no progression).

Pros and Cons

  • Very simple to use
  • Not aggressive- your bets won’t accelerate like in the Martingale System.
  • You won’t claw back all of your losses
  • Doesn’t alter the odds you get at the table.

More Details

The D’Alembert System is relatively easy to use- it is often used on the even money bets (e.g. red, black etc). The system was developed from French mathematician Jean Le Rond d’Alembert’s theory of equilibrium.

In a nutshell, his theory was that iif something occurs with an equal chance of taking place (e.g. flipping a coin, or even/odd on a roulette wheel), and you start to see a lot of one outcome (lots of reds for example), then the opposite outcome must at some point “kick in”, so that the natural order of things can be restored.

Charles’ System?

The system was thought to have been used by Charles Deville Wells in 1891 when he broke the bank in Monte Carlo, winning 1 million French Francs (around $13 million in today’s money). But others say he used the Martingale, or he cheated.

So, if you keep seeing reds, the wheel should switch to black, at some point in the future.

So how does this translate into a system? Well, the D’Alembert System takes the emotion out of roulette, and aims to make your betting more methodical. The closest thing we can think of to describing it is card counting in blackjack.

The D’Alembert does not alter your odds, however. The basic theory is to try and bank your profits after a win (bet reduces) and claw back money after a loss (bet increases). It’s a gentle negative progression system (other negative progressions include the Fibonacci System and its more famous cousin: The Martingale).

How do You Play it?

Add a unit to your last bet if you lose and take away a unit if you win. It’s that simple. This system is best used on a relatively long session, say 20 bets and over, as you are hoping that your overall red/black ratio (as an even money bets example) will settle out at 50/50 over the medium to longer term. It might not, of course!


Say you bet £10 on black and your bet loses, increase your next bet to £11. If this wins, take your next bet back down to 10.

Where’s the catch?
Well, there’s also a 0 pocket in roulette (there are 2 in American Roulette). If the ball drops in this, you also lose (this is what gives the house its edge incidentally).

The Best Casino and Variant for The D’Alembert System

We recommend playing the D’Alembert System on the 3D game on All British Casino.