Fibonacci Dozens shows up again and again in roulette videos: steady wins, a progression everyone recognises, and a promise that the dozens are the "safe" way to play. We built it level by level and ran it through our full simulation. Here is what 10,000 players — and an endurance test — tell us.
The system
Fibonacci Dozens bets on the dozens, a 2-to-1 bet, and raises the stake after losses following the Fibonacci sequence: each step is the sum of the two before it. In the version we tested, ten levels take the total stake from $5 to $275 a spin:
| Level | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
|---|---|---|---|---|---|---|---|---|---|---|
| Stake | $5 | $5 | $10 | $15 | $25 | $40 | $65 | $105 | $170 | $275 |
Play every level once and you've staked $715 — 143 times the first bet. We simulated the system with a $1,000 bankroll. You can see every level on the table on the Fibonacci Dozens system page.
The results: 10,000 players, three goals
Each simulated player starts with $1,000 and plays until they either reach the profit goal or bust — can no longer cover the next bet.
| Goal | European win rate | Bust risk | Avg spins | Avg result |
|---|---|---|---|---|
| +$50 | 93.2% | 6.8% | 15 | −$10.92 |
| +$100 | 88.0% | 12.0% | 27 | −$22.15 |
| +$200 | 78.9% | 21.1% | 48 | −$43.75 |
At first glance it's impressive: more than nine in ten players reach +$50, and they get there in about 15 spins. But look at the last column. Averaged over all 10,000 players, the result is negative at every goal.
On an American wheel
With a double zero, every number moves the wrong way: 92.1% reach +$50 (bust risk 7.9%), 86.4% reach +$100 and 76.2% reach +$200, with average results of −$22.11, −$38.20 and −$76.49. At +$200, the average loss is almost twice as large as on a European wheel. More in European vs American roulette.
The endurance test: what happens if you keep playing
Goals end sessions early. To see what happens when they don't, we let 1,000 players run the system for a fixed number of spins with no profit target:
| Spins played | Still in the game | Median bankroll |
|---|---|---|
| 50 | 82% | $1,180 |
| 100 | 66.8% | $1,265 |
| 200 | 51.5% | $935 |
After 200 spins, almost half the players have busted — they could no longer cover the next bet — and the typical player is below where they started. The survivors who did well did very well — a lucky tenth had $1,900 or more — but you can't choose which group you'll be in.
What the numbers mean for you
It is a short-session system. Fibonacci Dozens does what it's built for: it reaches a small goal quickly and very often. Its strength is entirely in the first few dozen spins.
Keep the goal small. Moving from +$50 to +$200 triples the bust risk, from 6.8% to 21.1%.
Respect the price tag. One full losing run costs $715. If that number makes you uncomfortable, this system isn't for your bankroll.
Stop when the session ends. The endurance curve is the clearest argument for stop rules we've seen: the longer you play, the more the house edge wins.
Our verdict
Fibonacci Dozens is one of the better-behaved systems in our catalog for short sessions on a European wheel. It is not a way to make money: averaged over everyone, the result is negative at every goal, and it gets worse the longer you play. Play it for a small, defined goal, with a bankroll you can afford to lose — or try it in Play it first and see how a losing run feels without risking a cent.