Short answer: there's no betting strategy that beats roulette. We ran six popular systems through 100,000 simulated sessions each, and every one of them lost about 2.7% of the money wagered on a European wheel. What changes between systems is how you lose: often a little, or rarely a lot.
The six systems we tested
- Flat betting: the same bet on red every spin.
- Martingale: double the bet after every loss.
- D'Alembert: add one unit after a loss, remove one after a win.
- Fibonacci: follow 1, 1, 2, 3, 5, 8… one step up after a loss, two down after a win.
- Paroli: double after a win, bank the profit after three wins in a row.
- Single number: the same bet on one number every spin (pays 35 to 1).
Results: 200 spins
Using the same engine as our free roulette simulator: European wheel, €100 bankroll, €1 base bet, €500 table maximum, 100,000 sessions per system.
| Strategy | Sessions in profit | Lost whole bankroll | Average result | Average wagered |
|---|---|---|---|---|
| Flat €1 on red | 32.5% | 0.0% | −€5.42 | €200 |
| Single number | 44.9% | 19.1% | −€5.12 | €188 |
| Paroli | 35.7% | 0.0% | −€9.12 | €338 |
| Fibonacci | 62.9% | 31.8% | −€11.54 | €435 |
| Martingale | 44.5% | 50.7% | −€14.12 | €516 |
| D'Alembert | 41.2% | 52.9% | −€24.75 | €925 |
Results: 1,000 spins
Same setup, five times longer. This is roughly a long evening at a fast online table.
| Strategy | Sessions in profit | Lost whole bankroll | Average result |
|---|---|---|---|
| Flat €1 on red | 18.6% | 1.7% | −€26.94 |
| Single number | 31.9% | 63.3% | −€15.10 |
| Paroli | 22.5% | 28.8% | −€41.52 |
| Fibonacci | 23.5% | 76.2% | −€37.72 |
| Martingale | 12.4% | 86.9% | −€35.94 |
| D'Alembert | 6.8% | 93.1% | −€68.15 |
Single-number betting loses less here only because most sessions run out of money early and stop betting. Per euro wagered, it costs the same as everything else.
What the comparison shows
- Average loss = money wagered × house edge. Look at the last column of the first table: the systems that put more money on the table lose more, almost exactly in proportion.
- Loss-chasing systems win often and bust hard. Fibonacci, Martingale and D'Alembert finish ahead more often than flat betting, but they wipe out the bankroll in a third to half of sessions.
- Paroli and flat betting are the gentlest. Neither chases losses, so a bad run costs one unit at a time.
- Time is the enemy of every system. At 1,000 spins, the share of winning sessions falls for all of them.
Why no system can work: each spin is independent, and every bet on a European wheel returns 97.3 cents per euro on average. Changing the size or order of your bets rearranges wins and losses, but it can't turn a series of losing bets into a winning one.
The choices that actually matter
If no system wins, what can you control? These four things change your results far more than any betting pattern:
- The wheel. European roulette costs 2.70%, American 5.26%, and French roulette with La Partage only 1.35% on even-money bets. See European vs American roulette.
- How much you bet in total. Smaller bets and fewer spins mean less money exposed to the house edge.
- Your limits. Decide your loss limit, time limit and win goal before you start. See how to set a roulette budget.
- Knowing your real results. Most players remember their wins and forget their losses. Logging every session shows where your money actually goes.
Want to check these numbers yourself? Every system above is in the roulette simulator. Pick one and run 1,000 sessions.