Published on March 24, 2026 • Updated: 2 October 2026
Spectators in the Colosseum bet on fighters, and even then some believed a clever way of staking could beat chance. Betting systems are the modern version of that hope: rules that tell you how much to bet after a win or a loss. This article works through the best-known systems with numbers, so you can see what each one really does. All examples use European roulette (37 pockets, single zero) and are labelled assumptions.
The starting point: a 2.70% edge on every bet
An even-money bet such as red wins on 18 of 37 pockets, a probability of about 48.65%, and pays 1:1. The zero is why the casino keeps on average 1/37 of every stake, which is 2.70%. This applies to every bet on the table. A betting system decides how much you stake and when; it cannot change that percentage. The expected loss of any session is therefore about 2.70% of everything you put on the table.
Martingale: double after every loss
You bet on red and double the stake after each loss, so that the first win recovers all losses plus one base bet. Assumptions: base bet €5, table maximum €500 (a table limit chosen for this example, not the operator's). The stakes go 5, 10, 20, 40, 80, 160, 320. The eighth step would need €640, above the limit, so after seven losses in a row the series is over and you have lost €635.
- Chance of seven losses in a row: (19/37)7, about 0.94%.
- So a series ends +€5 about 99.06% of the time and −€635 about 0.94% of the time.
- Expected result per series: about −€1.03. That is exactly 2.70% of the average amount staked per series (about €38).
- Over 100 series, the chance of hitting at least one seven-loss run is about 61%.
Martingale turns many small wins into one rare, large loss. It feels like it works until the day it does not.
Reverse Martingale: double after every win
Here you let winnings ride and stop after a set number of wins. Assumption: base bet €5, stop after three wins in a row. Three wins in a row (5, 10, 20) bring +€35, with a probability of about 11.5%. Any loss along the way costs only the original €5. Expected result per cycle: about −€0.39, again 2.70% of the average stake. The risk is smaller per cycle than with Martingale, but the edge is untouched.
D'Alembert: one unit up, one unit down
After a loss you add one unit to the stake, after a win you take one away. The system assumes that wins and losses will balance out. Assumption: €5 start, €1 unit, sequence loss, loss, loss, win, win, win. Stakes 5, 6, 7, 8, 7, 6: you lose €18 and win €21, a profit of €3. With equal numbers of wins and losses the system shows a small profit, but on roulette wins come slightly less often than losses, and long losing runs push the stakes up step by step. The expected loss is still 2.70% of the total staked.
Flat betting
The same stake every time. Assumption: €5 on red for 100 spins. You stake €500 and the expected loss is €13.50. The spread around that is wide: one standard deviation over 100 such bets is about €50, so finishing €40 up or €65 down is perfectly normal. Flat betting does not beat the edge either, but it keeps stakes predictable and makes a budget easy to calculate.
Hedging: covering both sides
Some players bet red and black at the same time to feel safe. Assumption: €5 on red and €5 on black. One bet wins and one loses, so you break even, except when zero lands (1 in 37): then both bets lose and you are €10 down. The expected loss is 2.70% of €10, the same as any other €10 of stakes. In sports betting, backing both outcomes means paying the bookmaker's margin twice. Hedging reduces swings, not costs.
| System | How stakes change | What it changes | House edge |
|---|---|---|---|
| Martingale | Double after a loss | Many small wins, rare large loss | 2.70% |
| Reverse Martingale | Double after a win | Many small losses, rare larger win | 2.70% |
| D'Alembert | +1 unit after loss, −1 after win | Slower stake growth than Martingale | 2.70% |
| Flat betting | Always the same | Predictable turnover | 2.70% |
| Hedging | Both sides at once | Smaller swings, same cost per stake | 2.70% |
What GladiatorsBet's bonus terms say about betting systems
The general bonus terms (last updated 13 February 2026, checked 2 October 2026) list several patterns as irregular play while a bonus is active (clause 1.7): betting systems such as Martingale, even-money bets, low-risk betting and staking more than 100% of the deposit in a single bet while a deposit bonus is active. Read that clause for the consequences before you play with a bonus. Two other rules matter for roulette players:
- The maximum bet with an active casino bonus is €5 per spin or bet, so a Martingale starting at €5 would break the limit at its second step.
- Table games count only 20% towards casino bonus wagering, and live casino does not count at all.
Put simply: a betting system does not improve your odds, and with a bonus active it can also cost you the bonus. Details of the current offers are on our bonuses page.
Country check: the operator's general terms (clause 2.5.4) do not accept accounts from, among others, Germany, Austria, France, the Netherlands, Spain, the United Kingdom and the USA, and its bonus terms (clause 1.15) exclude players from France, the Netherlands, Spain and other countries from all bonuses. Accounts can be suspended and winnings withheld, so read the terms before you register.
For the same logic applied to slots, see our guide to how slots work; terms such as house edge and wagering are explained in the glossary, and practical advice is on our tips page.
Frequently asked questions
Does the Martingale system work?
It wins small amounts often and loses a large amount rarely. In the example with a €5 base bet and an assumed €500 table limit, a series wins €5 about 99.06% of the time and loses €635 about 0.94% of the time, an average of about €1.03 lost per series.
Can a betting system beat the house edge?
No. A system only changes the size and order of stakes. On European roulette every bet carries the same 2.70% edge, so the expected loss is always about 2.70% of the total amount staked, whatever pattern you follow.
Can I use Martingale with a bonus at GladiatorsBet?
The operator's bonus terms (clause 1.7) list betting systems such as Martingale, even-money bets and low-risk betting as irregular play while a bonus is active, and the €5 maximum bet with a bonus would stop a Martingale at the second step anyway.
Sources: General Bonus T&Cs (updated 13 Feb 2026), Terms & Conditions (updated 17 Mar 2025); checked 2 October 2026. Roulette figures are our own calculations based on the stated assumptions.
