American Roulette · 38 Pockets · Statistical Analysis
The Roulette Probability Engine is a free, browser-based tool for tracking live roulette spins and simulating betting strategies across thousands of sessions. It covers every standard betting zone — straight-up numbers, splits, streets, corners, six-lines, dozens, columns, and outside bets — scoring each one using three independent statistical equations on every spin.
The tool supports both American roulette (38 pockets, 5.26% house edge) and European roulette (37 pockets, 2.70% house edge). Switch between them at the top of the page — all zones, scoring, and simulations update automatically.
Every roulette bet carries a built-in mathematical disadvantage for the player. On an American wheel, the presence of both 0 and 00 means the true odds of hitting a single number are 1-in-38, but the payout is 35:1 — a gap that creates a 5.26% house edge on every spin. European roulette's single zero halves that edge to 2.70%.
No betting system changes this. The edge is structural — it applies to every spin independently of what happened before. What betting strategies can control is variance: how quickly you gain or lose, how large your swings are, and how long your bankroll lasts in a session.
Same stake every spin. Lowest variance, slowest bankroll drain. The only strategy where results purely reflect the zone selection model, making it the best baseline for comparison.
Double after every loss, reset after a win. One win always recovers all losses — in theory. In practice, table limits and limited bankrolls make a long losing streak unrecoverable.
Progress through the sequence 1,1,2,3,5,8,13… after losses; step back two on a win. More gradual than Martingale, less volatile, but still subject to the same table limit ceiling.
Add one unit after a loss, subtract one after a win (floor: base bet). The gentlest progression. Works best on even-money outside bets. Rarely blows up a session in a single streak.
Double after each win, reset after a loss or three consecutive wins. Designed to ride hot streaks with winnings rather than your own bankroll. Lower catastrophic risk than negative progressions.
Sit out every spin until N consecutive losses have occurred on your chosen bet type, then enter for one flat bet. After a win, reset and wait again. Reduces total exposure by limiting how many spins you actually bet on.
Every betting zone is scored on each spin using three independent equations, each capturing a different aspect of recent spin history:
The three scores are combined using configurable weights (W1, W2, W3) that always sum to 1.0. All zones are then normalised to a 0–100 scale, where 0 is the coldest/most-underdue zone and 100 is the hottest. Results are sorted lowest-first in the live tracker — the zones at the top are the most statistically underdue.
No. The house edge in roulette is mathematical and permanent. This tool helps you understand probability patterns, test betting strategies, and make more informed decisions — but it cannot overcome the structural house advantage of 5.26% (American) or 2.70% (European).
P&L stands for Profit and Loss. It represents total winnings minus total stakes wagered across all bets in a session, measured in units (where 1 unit equals your base bet). A result of −52 with a $5 base bet means you lost $260 on average per session.
Always choose European roulette when available. The single-zero wheel has a house edge of 2.70% versus 5.26% for the American double-zero wheel. Over hundreds of spins that difference compounds significantly.
The sweep tests 81 combinations of scoring weights and decay rates across capped sessions for speed. The results indicate relative performance between configurations but should be validated with a full Run Simulation using your preferred settings. All results are subject to the same random variance as real roulette.
DISCLAIMER This tool is provided for entertainment and educational purposes only. It does not guarantee winnings or predict future outcomes. Roulette is a game of chance — no betting system or probability model can overcome the mathematical house edge. Never bet more than you can afford to lose. If you or someone you know has a gambling problem, please contact the National Problem Gambling Helpline at 1-800-522-4700 (US) or visit BeGambleAware.org.