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The D’Alembert system, which is named after a French scientist, is as simple as two plus two, but at the same time quite effective in casinos and sports betting. Initially, it was used when playing roulette, but then, with the development of betting, players successfully adapted it to bookmakers.

The famous French philosopher, mechanic and mathematician Jean Le Rond D’Alambert, who promoted science in the 18th century, never imagined that he would become such a popular figure in the gambling world a few centuries later. The betting management system based on his teachings is actively used by players in betting shops and casinos.

The main rule of the strategy is to increase the betting amount by one unit after losing and decrease it by one unit when winning. A unit is a value that equals the amount of the minimum bet. In a casino analogy, you should bet one more chip when you lose, and one less chip after each win.

The second rule of the system states that one should only play at odds above 2.00. As you know, the bookmaker always has an advantage due to the margin, but the player can even out this difference by using the D’Alamber system. By increasing bets arithmetically after losses, the bettor increases his chances over the long haul, as at odds from 2.00 he wins more than he lost in the previous step.

Strategy basics


D’Alamber’s system requires the user to make predictions on outcomes with equal odds. These are bets that lead to one of two outcomes with a probability approaching 50/50. A prime example of this is predicting red or black, even or odd in roulette. If one wins, one receives a payout and either leaves the bet size at the original level, if it was the first of the session, or reduces it by one increment. If unsuccessful, its amount goes up.
Unlike the Martingale strategy, D’Alamber’s system does not provide coverage for all previous losses with one successful spin. Several spins may be required before the user is in the black. However, this disadvantage is fully compensated by the reduced risks. While a geometric progression of betting growth allows for only a few consecutive predictions, arithmetic allows for longer sessions and protects against variance.
D’Alamber’s strategy, like any other betting system, does not guarantee a win. It only reduces the mathematical advantage of the casino on the short side.
This strategy can only be used in games where equal odds are stipulated. If the probabilities of one of the two outcomes are not equal or are far from 50%, the system cannot work even in theory.

An example of using the d’Alembert strategy

It is worth looking at how this concept works with a practical example. Let’s assume that the game bank assumes an amount of 100 conventional units. The unit is a bet of 10. This is the amount by which each successive bet will be increased if it loses.
Next, you need to consult the line to find the right event. It is important to check out the odds. If you lose money, you should already bet $20 on the other team winning and approximately the same odds. If you are unsuccessful, you can already bet $30 so that there is a chance to win back. If the bet goes in, the player will get his lost money of $20 and a profit on top. Then he can bet again, starting with 10 conventional units.

Advantages and disadvantages of D’Alamber’s strategy

This betting system is based on an arithmetic progression. This means that the effectiveness of the strategy is mathematically justified. However, the performance in practice may differ from the theoretical one. The strategy is designed with the expectation that predictions will be made on outcomes with a 50% probability of occurrence. But any gambling game gives a small advantage to the casino. In the example of roulette, this is the zero field, which reduces the odds of red and black to 48.65%. Within a few spins it may not be noticeable, but over a distance the deviation is palpable.


However, D’Alamber’s strategy has several important advantages over other betting systems:

  • It is less demanding on the deposit amount, as it is based on arithmetic progression.
  • For the same reason, the system is considered not too risky and allows for long sessions.
  • The effect of variance is markedly reduced compared to Martingale.
  • It is easy to learn, and there is no difficulty in calculating the bet size while it is being used.

From these same advantages come some disadvantages as well. The main one is that after a prolonged series of failures, it can take a long time to come out in the black. Previous losses are not covered by one successful prediction.

When applying D’Alamber’s strategy, it is important not to give in to emotions and to remain consistent. If you deviate from the instructions even once and make a wrong bet, the cycle will have to start all over again.

Varieties of D’Alambera’s system

There is a methodology that is the exact opposite of d’Alembert’s strategy, Contra D’Alembert. In Contra D’Alembert, the bets are increased by one increment when you win and decreased by one increment when you lose. Thus, the game is played before a set amount is reached.
The bets then return to their original size. This system is suitable for those who do not want to raise their bets significantly when they lose.

Difference from Contre D’Almbert

In the strategy under consideration, the opposite mechanism works. That is, after a loss, it is necessary to reduce the bet by one unit, and after winning, on the contrary, increase it. If suddenly the first bet did not go, the amount of the bet remains unchanged. In this case, the user can better prepare for a likely black line, because the next bet will be less stressful after each successive win. But you won’t be able to recoup immediately according to this scheme.

Does the D’Alembert betting system work?


From a theoretical point of view, one can expect to win regardless of the strategy chosen. When practical matters are taken into account, it is worth remembering a simple thing: when the amount of the first bet is equal to 1% of the pot, you have to make 13 unsuccessful bets to lose all your money.

A player who uses such a scheme runs little or no risk of facing the limit set by the bookmaker’s office. However, betting on everything is not advisable; it is advisable to study the situation carefully and only then decide to make serious moves.

One final reminder that each number drawn has nothing to do with the previous number, so the effectiveness of systems based on such an approach is very relative. What is more, it will never protect you from losing, unless you can exploit some loophole in the rules.

In any case, if you gamble regularly, you need to be aware of the different systems, so that you can bet systematically in each case, not just relying on fortune.


Casino Games & Betting Expert

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Mārcis is driven and ambitious, particularly excelling in the realm of casinos, where his expertise lies in slot machines. He boasts an impressive knowledge of the industry's leading game developers and their creations. With a keen understanding of the games, he delves into the intricacies of each slot machine's bonuses and winning potential. Mārcis is eager to share his wealth of experience and insights, which is why he joined the Casinobaltics team. All together, they aim to educate our readers.



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