D’Alembert Betting System

The D’Alembert is among the easiest betting systems that are applicable to the game of roulette. In fact, this system ranks second in terms of popularity after the Martingale. It bears many of the characteristics of the Martingale, which is not surprising considering the fact that both systems are based on negative betting progressions. Therefore, the D’Alembert dictates that players should increase the size of their stakes after a loss and decrease it after each winning bet.

The origins of the D’Alembert system can be traced back to the 18th century, when the French mathematician Jean le Rond D’Alembert began his work on a statement of the fundamental laws of motion. The mathematician came to the conclusion that the external forces acting on a body and the inertial forces are a system which exists in equilibrium. This conclusion laid the foundations of Newton’s Second Law and became known as the D’Alembert Principle.

How Does the D’Alembert Betting System Work

When applied to games of chance like roulette, D’Alembert’s law of equilibrium leads to the idea that future outcomes of wheel spins can balance less likely results in the past. According to D’Alembert, the chances of a coin landing on tails increase if it has already landed on heads several consecutive times.

In other words, if the ball lands in red pockets several times in a row, black is due to be spun and becomes a more likely outcome. This concept is also known as the Gambler’s fallacy. However, this serves as an indication that the D’Alembert system is based on the idea that players, who place even-money bets, will generate a profit if they win as often as they lose or more.

When the flip of a coin is taken into consideration, 50% of the time, the result that will come up will be tails, and 50% of the time, it will be heads. Although this is what the figures dictate, probabilities are not the same in the gambling realm.

What gambling enthusiasts should remember is that when they lay any of the roulette bets that pay even money, the chances of winning are not the same as with the flip of a coin. This is so because of the presence of the zero and the double-zero pockets in American-style roulette variants.

The D’Alembert system is quite simple to master even by roulette novices, which comes to explain why it is so hugely popular among casino enthusiasts. If you are keen on the idea to give the betting system a trial run, the first thing you need to do is set a base betting unit depending on the overall size of your bankroll. It is important to mention that your betting unit should not exceed 5% of your bankroll for the session. A betting unit of 2% is considered the safest option, especially for gambling aficionados who are reluctant to take risks or do not have that bountiful bankroll.

As it seems, some experienced roulette players advise going for a base bet unit that does not overstep the 1% threshold. Others go even further and recommend putting on the line an amount that is 0.50% of the funds you intend on using during your betting session.

Since the base bet unit you will settle on will be the backbone of this roulette betting method, it is of crucial importance to pick it wisely due to the fact that it willdetermine the net profit you are expected to accumulate during your betting session.

The D’Alembert system dictates that you should start by placing an even-money bet of precisely one betting unit. If luck is not on your side on the first spin and you lose, you need to increase your next wager with one betting unit. What you need to do is to keep on increasing your wagers with a single betting unit after each loss.

After each winning bet, you are required to reduce your next stake with one betting unit. If your first bet is a winning one, you continue wagering with the same base betting unit until you lose. The idea here is that if a given player wins and loses roughly the same number of times, they will eventually turn a profit.

It would be best to demonstrate how the D’Alembert betting method works in practice by providing an example. Let’s assume your bankroll is £250 and your betting unit is £5 or 2% of the overall sum you intend to join the roulette table with. You bet £5 on Red and lose. You increase your next wager with one betting unit, so you bet £10 on Red and lose again. At this point, you have lost £15.

You increase your next wager on Red to £15 and win this time, thus collecting £15 in net profit. After this success, you are supposed to reduce the next wager with one betting unit to £10. You bet on Black and win again, generating a net profit of another £10. It becomes clear you have won £25 with your last two bets and have lost only £15 with your two losing wagers, so your net profit for this betting session is £10.

As you can see, the D’Alembert system works efficiently as long as the number of winning bets coincides with or exceeds that of losing bets. Of course, there is the option to set a limit at which you will stop increasing the stakes after a loss and reduce the betting unit to its initial size h. This modification can help you minimise your losses if you happen to enter a longer losing streak.

The D’Alembert System
Spin Bet (units) Outcome Total Profit
1 5 LOSS -5
2 10 LOSS -15
3 15 WIN 0
4 10 WIN 10
5 5 WIN 15
6 5 LOSS 10
7 10 LOSS 0
8 15 WIN 15
9 10 WIN 25
10 5 LOSS 20
11 10 WIN 30
12 5 WIN 35
13 5 WIN 40

The Reverse D’Alembert

As it can be expected from the name, it functions in the opposite way but is suitable for even-money bets in roulette.

Players are again recommended to choose a base betting unit which should range between 2% and 5% of their overall bankrolls. Their first even-money bet should be one betting unit. According to the Reverse D’Alembert, players should increase their stakes by one betting unit after each winning bet and decrease it after they see a loss.

So if your first bet of £5 on Red wins, your second bet should be no more than £10. If you succeed in predicting the winning number again, your next wager needs to be £15, and so on. When players lose a bet, they are required to decrease their next stake by one betting unit. So, if you lose your third bet of £15, you reduce the next wager to £10.

One major advantage of the Reverse D’Alembert is that it enables players to minimise their losses. Those, who implement the Reverse D’Alembert are less likely to exhaust their bankrolls when they experience a lengthy losing streak. Besides, implementing this variation may prove to be rather profitable if the player wins several bets in a row.

What gambling aficionados should take into account is that while employing the Reverse D’Alembert betting system, the results they will ultimately enjoy might not be that bountiful as the ones delivered by its original version.

Yet, one of the biggest benefits roulette lovers will enjoy if they decide to give this betting method a shot is that they will be able to put it through its paces even if their bankroll is rather humble. Furthermore, if fortune does not smile on you and you end up on a sustained losing streak, you will not find yourself with no other solution but to risk a bigger chunk of your funds so as to make up for the losses you have seen in the previous rounds.

As with the original version of the D’Alembert betting system, while making use of its reversed version gambling enthusiasts are advised to settle on a stopping point before they kick it off. As it seems, the better part of the gambling aficionados recommends starting the betting progression all over as soon as you augment the staked amount five times.

Although taking the betting progression further might seem like an alluring idea because the potential payoffs will be more generous, players should bear in mind that the risk they will need to take will increase significantly.

The Reverse D’Alembert System
Spin Bet (units) Outcome Total Profit
1 5 WIN 5
2 10 WIN 15
3 15 LOSS 0
4 10 WIN 10
5 15 WIN 25
6 20 LOSS 5
7 15 LOSS -10
8 10 WIN 0
9 15 WIN 15
10 20 LOSS -5
11 15 WIN 10
12 20 WIN 30
13 25 WIN 55

How to Tinker the D’Alembert Betting System

If you plan on putting the D’Alembert betting system to the proof, you should be aware that there are few more modifications that can be made to it. The results players might ultimately enjoy can turn out to be rather interesting, given that they do not increase the staked amount by one betting unit each time their wagers are settled as losing ones and instead bring the betting progression back to square one.

The reason why many roulette mavens are unlikely to frown upon this variant of the betting system is that even if they place several losing wagers, this will not have such a major impact on their bankroll.

If gambling enthusiasts decide to take advantage of this modified version of the roulette betting method, the winnings they are expected to generate should make up for the losses they have seen during their betting session.

One factor gambling enthusiasts should not forget is the edge the casino gains over them whenever they play. In spite of the fact that the usage of this betting method will help players reduce the losses to a minimum, they should remember that ultimately, they will invariably lose to the casino.

Still, the fact that the casino invariably holds the upper hand over players should not put you off from the betting system. In essence, if luck is on your side that day, you might enjoy a long winning streak that can bring you a massive payoff.

Advantages of the D’Alembert Betting System

Without question, the biggest advantage the D’Alembert system has to offer is its very simplicity. It does not require players to take notes like some other systems do. On the contrary, the system is quite easy to learn and incorporate at the roulette table.

Another advantage results from the fact that while using this betting method, there is no steep increase in the bet size with this negative progression system. As wagers are increased with a single betting unit after each loss, a longer losing streak is less likely to drain your bankroll completely. On some occasions, the D’Alembert system also enables those who follow it to generate a consistent profit.

The size of the wager after each loss is increased slowly which renders the system suitable for players who do not have that many funds to play with. Besides, the risk of reaching the table limit on a lengthy losing streak is much smaller if you implement the D’Alembert, which does not apply to some of the other betting methods.

Disadvantages of the D’Alembert Betting System

Similarly to the other betting systems we have discussed so far, the D’Alembert has a few faults. The system is most effective when it comes to generating short-term profits. Though consistent, the winnings will be far from life-changing which is to be expected from a system that involves a relatively low degree of risk.

Then again, in order to turn a profit at all, players are expected to win and lose roughly the same number of times. Unfortunately, there is no guarantee that this will happen since the chances of winning and losing with even-money bets in roulette are not exactly 50%. The scales are tipped in favour of the casino because of the introduction of the zero pocket on the wheel. Even more so, if one plays American roulette, where there is an additional double-zero pocket, which further increases the house edge. Statistically speaking, players lose more often than they win which would make it more difficult for them to recover from their losses.

Entering a longer losing streak is not that unlikely, either. If a given player suffers five or six losing bets in a row, there is no guarantee they will succeed in winning the same number of times to offset the losses. Essentially, players need to remember that neither the D’Alembert nor any other betting system can reduce the house edge or influence the spins. This is so because the outcome of each spin is not affected by the previous numbers which had been spun on the wheel.

Dangers of Using the D’Alembert Betting System

As we mentioned above, the D’Alembert betting system revolves around the idea that ultimately, the number of losing and winning wagers gambling enthusiasts have laid will balance. In spite of the fact that this claim makes perfect sense to roulette lovers, what they fail to take into consideration is that in order for the results to come out even, the period that should be taken into consideration will be dramatically prolonged.

In essence, this is exactly where the main lacking point of the betting system stems from because the frequencies of the opposite results are unlikely to balance during the betting session of players unless they do not spend a huge amount of time at the roulette table.

That is the reason why this idea is unworkable when the game of roulette is concerned. In the event that the number of winning and losing wagers does not balance during the time casino enthusiasts wager, they might end up with no winnings at all, which is certainly not a desirable scenario.

That being said, what makes many roulette players give the betting system a chance is that unlike the Martingale betting method that is exceptionally aggressive, this is not the case with the D’Alembert betting system for the simple reason that gambling aficionados will not be prompted to double the staked amount whenever a loss incurs.

As it was already mentioned, with the D’Alembert betting system, the amount you need to put on the line following a loss will be increased by a single bet unit, which undoubtedly adds up to a big difference.

Although the D’Alembert betting system appeals to gambling aficionados because of its inherent simplicity, roulette lovers should not forget that its usage will not have any influence on their chances of win. The same applies to the house edge as no matter if you are bound to take advantage of the D’Alembert betting method or any of the other roulette betting systems available out there, losing to the house is unavoidable.


At the end of the day, many gambling aficionados are eager to try their hand at the D’Alembert betting system because there are not any complex calculations that should be made while adapting their stakes to the outcome of the previous round. Another thing that makes the betting method so immensely popular among casino enthusiasts is that it is a much safer alternative when compared to the rest of the betting systems that can be applied to the game of roulette because the amount they will need to risk will not soar.

With that in mind, gambling aficionados will not stand such a good chance to walk away with a heftier payout. In a similar vein, making up for the losses they have seen might only be possible after placing several successful wagers, which can sometimes be hard.

As you can see, using the D’Alembert betting system has its pros and cons that should be evaluated, but it is worth considering as an option if you are still not confident enough to make use of other riskier roulette betting methods.