The D'Alembert Roulette System

The D'Alembert betting system is a 'negative progression system', and assumes that there will be an equal number of wins and losses on 'even money' bets.. It was dreamed up by Jean le Rond d'Alembert, a French mathematician, in the 1700's. This system should only be used on the even money bets like red/black, even/odd, and low/high 18. Because of its simplicity, this is one of the most popular roulette systems, and it has been around since the very beginning.

How It Works

To use the D'Alembert system, start by making an even money bet. Any size will do, but try to go with a bet you would normally be comfortable making without the system. If this bet wins, the system assumes that a loss is more likely on the next spin, so you should make a smaller bet. When you lose bets, the system predicts that another loss is less likely so you increase your bet. For small bets, each bet you will only be changing the stakes by $1, but at larger stakes, you might be adding/subtracting thousands of dollars each time. Here is an example of series of six bets using the D'Alembert system.

With three wins and three losses, even not in a perfect back and forth order, you win a total of $3. This situation of equal wins and losses is what the system is built around.

The Good

The D'Alembert system has a few distinct advantages over other systems, and this why it has survived so long. The biggest benefit here over systems like the Martingale System is that your bets will not get too big too fast. This eliminates the problems with table limits, and keeps you from getting too deep too fast.

Also, since you only have one bet at a time locked into the system, you've got some flexibility. At any point during the game you can walk away, whether that means cutting your losses, or quitting while you are ahead.

The Bad

This system is designed to protect your bankroll when it believes you should be most vulnerable, and take advantage of statistically beneficial situations. This is, however, further built on the assumption that these even money bets are going to win and lose exactly half of the time. The truth though, is that these bets only win and lose 47.37% of the time. So if wins and losses only make up 94.74% (47.37% x 2) of the total spins, then what happens the other 5.26% of the time? That 5.26% is the house edge, created by the '0' and '00' pockets.

The Ugly

Well you've just read this entire article, and maybe you were starting to think that the D'Alembert system could work for you. Well, I hate to burst your bubble all the way down here, but the entire premise behind the D'Alembert system is flawed. The idea that one spin in the past will affect the spins in the future is a gamblers fallacy. Each and every spin of the wheel (or roll of the dice for that matter) is an independent event, totally free from the influence of the previous spins. By using the D'Alembert system, you are buying into this faulty, yet natural, logic and putting your hard earned money at risk.