Despite the fact that roulette is a balanced game that cannot be beaten using mathematics, a number of systems have been created over the decades in an effort to get the better of the wheel.
The most famous is probably the Martingale System, but a close second is the D’Alembert System was dreamt up by Jean-Baptiste le Rond d’Alembert, a French mathematician and physicist among many other things.
It is not hugely different from them Martingale: both are negative progression systems which increase the stake size after a loss, but the D’Alembert does so more carefully which can improve the life of your bankroll.
To use the system you will need to stick to even money bets, so red or black, odd or even, high or low.
How Does the D’Alembert System Work?
The first thing you need to do is break your bankroll down into units.
If you have £100, a good unit size might be £1 or £2 per unit, as this should give you plenty of longevity even if you hit a losing streak. Try and find a good balance that won’t wipe you out too quickly, but that also gives you the opportunity to make some money if things go your way.
As a general rule 5% of your starting bankroll per unit is the absolute maximum you should go to. With a £100 bank roll that would be £5 per unit. Remember, you are going to be increasing your stake by 1 betting unit after each loss, so with a 5% stake (£5) it only takes 3 losses in a row and you are £30 down and betting another £20 on the next game – that’s half your bankroll in four games.
To begin the cycle you would bet 1 betting unit on any even money bet, then wait for the result to roll in.
A win at the beginning would see you stick to the same bet size for the next game, while a loss would see you add 1 betting unit to your stake size, so the next bet would be 2 betting units, and if that one lost the next would be 3 betting units and so on.
Once you win a game your bet size would decrease by one betting unit. So if you had 3 units on the table and won, your next bet would be 2 betting units.
Here is an example of 10 games using £1 stakes and a £100 bank roll, that demonstrates the system in action:
So you see with regular changes in fortune your balance can move around a bit without ever going too far in one direction, so it is a more defensive system. However, a long losing streak can cause problems if it goes on for too long and you don’t reset the system, as your losses will climb higher and higher on each spin.
Conversely, a long winning streak won’t actually see you win eye watering amounts because once you get back to a single betting unit you are simply boosting your bankroll by one unit for each win. Therefore, unless you use large betting units the amount of money you can walk away with isn’t going to be life changing.
The other thing to note is that in the short term this system can do alright for you, but in the long term you will always lose. Your stakes will either become too high after a losing streak or you will hit the table limit eventually – either way your losses are then crystalised.
Adapting the D’Alembert System
It is possible to play around with the D’Alembert system a little bit.
Some people choose to increase their stake size after a loss by two or three units instead of one, to give themselves a chance of clawing back losses more quickly, and maybe even leap frogging ahead to some profit.
However, be aware that this will only work if your luck changes and you hit a win shortly after your loss; a long losing streak will just see this approach deplete your bankroll faster.
Another trick is to give yourself an increase limit.
For example, you might decide that once you have lost three times in a row, duly adding an extra unit to your stake after each loss, you will reset the system and go back to betting a single unit.
This will stop your losses climbing too high on a long losing streak, but also means that your next win will be smaller, as your stakes will not have continued increasing at the same rate. This means the books won’t balance so quickly, or at all.
Questions About the D’Alembert System
Does the D’Alembert System Guarantee a Profit?
No, it absolutely does not. In the short term it can work out in your favour, but in the long term you are extremely unlikely to walk away in profit. This means that if you are going to use it, you should go in prepared to walk away when you have won and/or lost a certain amount of money.
Really, you should use it as a bankroll management system rather than a tactic to win money.
Are There Other Roulette Systems Like the D’Alembert?
Yes there are a number of them, although none of them work as a way to beat the game.
The Martingale system is the most famous as we discussed at the top of the article, but you may also come across the Fibonacci and the Labouchere systems, which we also cover on this site.