The D´Alembert System has some similarities to The Martingale System and is best used on even money wagers (eg odd/even). It’s a negative progression. It’s alot less aggressive than the Double Up Systems, especially the Super Martingale.

This system was inspired by French mathematician Jean Le Rond d’Alembert’s theory of equilibrium. D’Alembert’s theory, was that if something occurs with an equal chance of taking place (eg flipping a coin, or even/odd on a roulette wheel), and you start to see alot 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.

Play the Paroli System at bet365- a roulette player friendly casino. 

Basically you add a unit to your previous wager if you lose and take off a unit if you win.
D´Alembert is most often used on even money bets over the length of your roulette session- so if you remain at the wheel for 50 spins and you are betting on red/black, you are taking a punt that you are going to get 50 red and 50 black.

This may not materialise, of course, even over the course of 50 spins. You might get a run of red at the beginnning of the session and find that the remainder of the session is biased towards black. And you might get a 0 (or 00 if you are playing American Roulette)

So, say you place a £5 wager on red and you lose, double your next wager to £10 on red. If you subsequently win, take your next wager down by 50%, back down to £5. By building up your bets when you lose, the theory is that you recover your loss and make profit on the wins. So very similar to the Martingale, except that you do not reduce your bet down to the initial unit when you lose, you just head back down the progression. So be warned, D´Alembert is more risky.

For D´Alembert to work you need an even spread of the even money bets, i.e. a 50:50 distribution. This is by no means guaranteed! And then you have the zero pockets, which means that the probability on so called “even” money bets are in fact south of even money.

Our advice on the system is similar to that which we would give for most roulette systems such as the Fibonacci and the Paroli System. Understand its limitations and pitfalls, and run low risk tests to gauge how your luck runs with them.
D´Alembert will not guarantee you untold riches at the roulette table, but it will give you a roulette system that will force you to play with some method. Is this a good idea? On balance, we would say yes, because it helps you to make rational judgements at the wheel, rather than emotional ones.