The D’Alembert betting system is somewhat unique in that it was designed to be used with a variety of casino gambling games, especially those that involve cards. As our primary focus is blackjack, we’ll be looking at the D’Alembert from that angle. It is equally adaptable to craps and roulette when fully mastered.
The French mathematician Jean le Rond d’Alembert is credited with being the person to invent this betting system, basing it on something he referred to as the “equilibrium of nature.” It should come as no surprise that the D’Alembert system was highly influenced by Martingale systems give that both of them originated in France. The ultimate goal of the D’Alembert is much the same as the Martingale. The player seeks to either break even or win a small profit.
Among betting systems, the D’Alembert is classified as a negative progression system, and this is where is digresses from the Martingale. In the D’Alembert system the player works their way through a progression of reduced bets. In other words, the underlying philosophy is to reduce one’s bets when winning. This is one of the great weaknesses of the D’Alembert system. As we have shown in many other articles on Counting Edge, negative betting progressions are particularly unsuited to blackjack.
Negative progression systems, such as the D’Alembert, require a much larger bankroll to execute successfully. The beginning blackjack player will find them especially distasteful. Nevertheless, for the purposes of information, the following paragraphs give an example of how the D’Alembert works at the blackjack table.
In the D’Alembert system, the player increases bets after a loss and reduces them after a win.
So, let’s look at a series of hands using the system:Restart the progression with a bet of four units.
On the surface, the D’Alembert System looks pretty good. In the above scenario, comprised of five blackjack hands, a player bets a total of 46 units for a net profit of 16 units. Indeed, a good streak of winning hands at the blackjack profit can yield a good profit when using the D’Alembert. Upon closer inspection, however, the dangers of this betting system are revealed.
Because the system demands the player double their bet after each loss, the inherent danger of getting wiped out by a bad losing streak is very high. If a player were to lose as few as five hands in a row, the sixth bet in the progression (128 units in the above example) would exceed the table maximum that is used by the casino to deter betting systems like the D’Alembert and the Martingale. In other words, the player would not be able to make a bet large enough to get even with the house. Blackjack, perhaps more than any other card game in the casino, is a game of swings and streaks. This makes the D’Alembert a very dangerous system to use in blackjack.
You will also note that the D’Alembert system requires you to begin with a bet of four times the table minimum. This is because the system requires you to reduce your bets when winning. If you begin at the table minimum there is nothing to reduce if you win the first few hands! Therefore, we need to take another look at the above example and assume a losing streak in the beginning:
How does the above example translate to actual dollars at the blackjack table? Let’s assume that you are playing at a $5 table. In just five hands you will have lost a total of 124 units. 124 X $5 = $620. Imagine losing $620 dollars in just five hands of blackjack—at a $5 table! If you are unlucky enough to catch a losing streak like this as soon as you sit down to play, you’ll be up and gone from the blackjack table before you even have time to get a free drink from the cocktail waitress.
Anyone who has played blackjack will tell you that it is very possible to lose five, six, seven, or even more hands in a row. This is why the D’Alembert system is so dangerous to use. If you do not win a few hands right away, the D’Alembert is almost useless and it has the capacity to wipe out your entire blackjack bankroll. There are other blackjack betting systems which will give you a greater chance of reward while minimizing your risk.