Enter a sequence of wins and losses to see how the D'Alembert progression changes your stake and bankroll.
| Bet | Result | Units | Stake | Bankroll |
|---|---|---|---|---|
| Calculate to see the progression. | ||||
D'Alembert changes stake size after wins and losses. It does not change the probability of the underlying bet or remove the house edge.
The D'Alembert system is a betting progression where the stake increases by one unit after a loss and decreases by one unit after a win.
Unlike Martingale, which can double stakes after losses, D'Alembert increases the progression much more gradually.
If your base unit is €10, the progression might move from €10 to €20 after a loss, then €30 after another loss. A win would then reduce the next stake by one unit.
The progression does not go below the original one-unit stake.
So if you are already betting one unit and win, the next bet remains one unit.
Suppose you start with a €500 bankroll, a €10 base unit and decimal odds of 2.00.
Your results are: L, L, W, L, W, W.
Starting from €500, the bankroll changes like this:
The final result is therefore a €30 profit, and the progression returns to the one-unit level.
Martingale typically increases stakes exponentially after losses. D'Alembert only adds one additional unit.
This makes D'Alembert less aggressive in the early stages of a losing streak.
But slower progression also means that one win does not necessarily recover every previous loss immediately.
Although D'Alembert grows more slowly than Martingale, the stake still increases after every consecutive loss.
With a €20 base unit, ten consecutive losses would eventually push the stake to €200 while previous losses have also accumulated.
D'Alembert is traditionally discussed with approximately even-money bets because its simple one-unit progression assumes wins and losses have similar financial weight.
A €30 winning bet at 1.70 produces less profit than the same €30 winning bet at 2.00. The D'Alembert sequence still changes by one unit either way.
This calculator therefore uses the actual betting odds entered when calculating bankroll changes rather than assuming every winning wager produces one unit of profit.
Sometimes a sequence of wins after losses can recover the deficit, but recovery is not automatic.
The result depends on the exact order of wins and losses, the betting odds and the stake level at which each outcome occurs.
D'Alembert controls the size of the next stake. It does not guarantee that accumulated losses will be recovered after any specific number of wins.
No.
If the underlying wager has negative expected value, increasing or decreasing the stake according to D'Alembert does not turn it into a positive expected value bet.
The progression only changes how much money is exposed after previous wins and losses.
Compared with Martingale, the progression grows slowly. Moving from one unit to two, then three and four can feel much more controlled than repeatedly doubling.
That does reduce the speed at which stake sizes increase, but it does not remove the possibility of a long losing run.
The bankroll can still experience significant drawdown when several losses occur before enough wins arrive to move the progression back down.
D'Alembert may grow more slowly than Martingale, but the staking pattern itself does not improve the expected value of the wager.
D'Alembert is easier to understand when you can see the full progression rather than looking only at the next stake.
This calculator tracks every win and loss, shows the exact number of units used, calculates the bankroll after every bet and displays the stake required for the next step.
That makes it easier to see D'Alembert for what it actually is: a bet-sizing progression, not a system that changes the underlying probability of winning.