D'alembert Betting System

The D’alembert is a system that allows players to make up more than they lost if they bet more immediately after a loss. Players can increase their bet units on a loss as well as decrease their bet units on a win when they apply this system to even chance bets. The rational of this system is quite similar to that of the Martingale system given that the player still has a possibility of wiping out their bankroll or reaching the roulette table limit if they have a long consecutive losses sequence or a time period where ‘black’ occurs more often than ‘red’.


This is system became famous in the 18th century in Western Europe when people were looking for ways of beating the roulette wheel. It is this gold rush that resulted in the system that players still use today. Jean le Rond D’Alembert who was a mathematician is the person this system is credited to. This gentleman based the system on the idea that over a long run all the available numbers on a roulette system will come up at equal number of times. He therefore theorized that if a player makes a bet and wins, there are high chances that the next spin will result in a loss and vice versa. With these theories in mind, he came to the conclusion that players should bet less immediately after winning or bet more immediately after a loss so as to take advantage of the law of probabilities and therefore be eligible to massive profits.

Rules of the D’Alembert Roulette System

  • Players should always start the game with a mid sized wager. This means that they could take chips off the bet for several times and still have something left on the table. For example if a player has $20 they should use a table that will allow them to make several bets i.e. a $1 table which will allow them to make 19 bets.
  • Players should ensure that they only place their wagers on the 50/50 “outside bets” and that is black, red, odd, even, 1st 18 or 2nd 18 which are the only bets that work using this system.
  • Players should decide on what to bet on and stick to those specific bets for the entire game.

How to use the D’Alembert Roulette System

1. The first thing to do is to decide the denomination to be added and subtract to the bet after a win or a loss. This is because this amount is supposed to be consistent in order for the system to be a success.

2. The next thing to do is place a mid sized bet on the favourite 50/50 outside bet.

3. The next thing will be to take away the amount you decided on from your bet when you win or add it when you lose.

4. The other thing will be to wager this amount on the exact bet that you bet on the 2nd step.

5. Steps 3 and 4 are supposed to be repeated if you intend on playing the game.