Roulette system tester
Pick a betting system, play many sessions in seconds, and see what changes and what never does.
How the system tester works
This roulette betting system simulator plays many full sessions for you with play money. You choose a system and your limits, and the tester runs every spin by the rules of that system.
- Pick a system, for example Flat or Martingale.
- Pick a wheel and set your bankroll, base bet, table maximum, win goal and spin limit.
- Choose how many sessions to run.
- Press start and read the results and the histogram.
Each session stops when you lose the bankroll, reach the win goal, or hit the spin limit.
Run the same settings with Flat first. It gives you a clean baseline to compare every other system against.
Every setting explained
- System – the rule that decides your next bet after a win or a loss.
- Wheel – European has one zero and a house edge of 2.70% on every bet. American has two zeros and a house edge of 5.26% on every bet except the top line, which is worse. See European and American roulette.
- Bankroll – the play money you start each session with. If it runs out, the session ends as a loss.
- Base bet – the starting bet, also called one unit. Most systems grow or shrink from this amount.
- Table maximum – the biggest bet the tester allows in your session. Systems that double often hit this limit.
- Win goal – the profit at which you stop and walk away.
- Spin limit – the most spins in one session. Set it high to see long play.
- Sessions – how many separate sessions the tester plays. More sessions give steadier numbers.
If a system needs a bet bigger than your bankroll or the table maximum, the tester bets what it can. That is where many sessions break.
How to read the results and the histogram
After the run, you get a short summary:
- Lost the bankroll – how often a session ended with nothing left.
- Reached the goal – how often a session hit the win goal.
- Finished ahead – how often a session ended with more than it started, goal or not.
- Average result – the mean win or loss across all sessions.
- House edge predicts – the house edge times the total amount bet. Compare this with the average result.
The histogram shows final results. The horizontal axis is how much a session won or lost. The bar height is how many sessions ended there.
- Flat betting usually makes a wide hump just left of zero.
- Martingale-type systems make a tall bar of small wins and a thin group of very big losses far to the left.
- Reverse systems like Paroli make many small losses and a few large wins.
Do not look only at the tall bar. The small bars far to the left are where the money goes.
The ten systems in one line each
- Flat – you bet the same amount every spin.
- Martingale – you double the bet after a loss and go back to one unit after a win.
- Grand Martingale – you double the bet and add one unit after a loss.
- Reverse Martingale – you double the bet after a win and go back to one unit after a loss.
- Paroli – you double after a win and reset after three wins in a row or any loss.
- D'Alembert – you add one unit after a loss and take away one unit after a win.
- Fibonacci – after a loss you move one step up a list where each bet is the sum of the two before, and after a win you move two steps back.
- Labouchere – you write a short list of numbers, bet the first plus the last, cross them off on a win, and add the bet to the end on a loss.
- Oscar's Grind – you aim for one unit of profit per series and raise the bet by one unit only after a win.
- James Bond – you spread a fixed bet with most on the high numbers, a smaller part on the six-number line just below them, and a small chip on zero.
All even-money bets here pay 1 to 1. Full payouts are on the payouts page.
The key point: systems change the shape, not the cost
On a European wheel every bet has the same house edge. On an American wheel every bet has the same edge except the top line (0-00-1-2-3), which is worse at 7.89%.
A betting system only changes the size and order of your bets. It cannot change the edge.
So over many sessions the average result lands near the house edge times the total amount you bet:
- On a European wheel, you lose on average 2.70% of everything you bet.
- On an American wheel, you lose on average 5.26% of everything you bet (more if you use the top line).
What a system does change is how sessions end. Martingale gives many small wins and rare huge losses. Paroli gives many small losses and rare big wins. The average stays negative in both cases.
Systems that raise bets after losses also push your total bet up, so the cost in dollars often grows. No betting system beats roulette over time.
Watch the line "House edge predicts". Run more sessions and the average result tends to move closer to it.
New to the game? Start with the roulette rules or try a free roulette game.
Questions
Does any roulette betting system work?
No. A system cannot change the house edge on any bet, so the average result stays negative. A system can only change how often you win small or lose big.
Why does Martingale look good in the tester at first?
Most sessions end with a small win, so the tall bar sits just above zero. The rare sessions that hit the bankroll or table maximum lose more than all those small wins added together, so the average stays negative.
How many sessions should I run in the strategy simulator?
Run as many as you can. With few sessions luck swings the numbers a lot, and with many sessions your loss as a share of the total bet tends to get closer to the house edge.
Is the European or American wheel better for testing systems?
The European wheel has a house edge of 2.70% and the American wheel 5.26%. The same system loses more on average on the American wheel.
Why is my average result different from the house edge prediction?
Short runs include luck. The prediction is the long-term average, and the gap tends to shrink as you add more sessions and spins, because your loss as a share of the total bet tends to get closer to the house edge.