Blackjack strategy - D'Alembert Betting System
The D'Alembert is a simple betting system, which is based on the Martingale with a few tiny changes. When using the D'Alembert blackjack betting system, the player will raise his bet one unit after he loses and will lower the bet by one unit if he wins.
The D'Alembert is named after Jean le Rond D'Alembert, a French mathematician, physicist, and philosopher of the 18th century. One of his theories based on the Law of Equilibrium claims a long-term balance of failures and successes over the course of a row of events. Thus, according to the theory, everyone has a higher likelihood of a win after he loses and a higher likelihood of a loss after he wins. But the key word is "long-term." The D'Alembert's is a very popular progressive betting system, aka the "Pyramid System." It is most frequently used in roulette and baccarat, but it is also applied for blackjack. There is a Contra-D'Alembert betting system, the positive variant of the D'Alembert.
When used in blackjack, the D'Alembert claims to raise the bet by one unit after every loss, and to lower the bet by one unit after every win. The D'Alembert system is a risky progressive betting system in any case. The player must play with caution using the D'Alembert; but it's a less dangerous system than the Martingale (where it is necessary to double the bet instead of raising it by one unit).
The D'Alembert is easy to understand and follow.
For example, you're playing blackjack where a $5 is minimum bet (that is one "unit"). So, you start by placing a bet of $5. After the loss, your next bet will be $10 that is two units. In the event of winning, the bet will be $5. If you lose the second hand your bet will be $15. If this hand wins, you bet $10, so you lower only by one unit, and not to return to the original bet.
1 lose 2 lose 3 win 2 lose 3
It is a mathematically losing system. You can exceed your bankroll or reach the table limit before hitting a winning hand.
There is also the Reverse D'Alembert System. You have to add one unit to the following bet after each win and decrease after each loss.
5 loss 4 loss 3 loss 2 win 3 win 4 lose 3
You must stop in time.Don’t increase your bet too much. Your winning streak can suddenly finish.