11/12/2009, Definitions
The D'Alembert Betting System is a popular casino betting strategy based on “The Law of Equilibrium”, invented by the French mathematician Jean Le Rond d'Alembert in the 18th century.
The system refers to winning or losing at the Roulette Table, Baccarat or Blackjack and it speaks of the “equilibrium in nature”.

The main strategy is to raise your bet one unit after you lose and to lower the bet by one unit if you win. Each bet will be either 1 unit higher or lower than the last one, depending if you win or lose.
A contra-D'Alembert system, which reverses the strategy by increasing the bets when winning and decreasing when losing can be also employed when necessary.
According to the theory, you have more chances to win after losing and higher chances to lose after wining. The system is also called the “Pyramid System” and it is easy to understand and to follow.

Let's take an example:
You bet $5 and you lose, so you will have -$5 gain.
You add another unit and you place $6.
Let's say you lose again, so you will have -$11 gain.
Add another single unit ($7) and if you win, you will have -$4 gain.
Then, according to D'Alembert system, you should decrease by a single unit, place $6, and if you win, you will have $2 gain and so on.

The D'Alembert betting system was originally designated for the roulette table, but it can easily be applied in Baccarat or Blackjack as well.
This betting system is less risky than the popular Martingale strategy, which means doubling your bet after each lose.