Random numbers
Every spin uses your browser's cryptographic random number generator (crypto.getRandomValues), the same source browsers use for security. A plain Math.random is not used.
The number is picked with rejection sampling, so there is no rounding bias: every pocket has exactly 1 in 37 (European) or 1 in 38 (American). Spins are independent: they never depend on your bets, your progression or earlier results.
Seed (repeatable runs)
With a seed the wheel uses a fixed sequence generator (mulberry32): the same seed always gives the same spins, so two progressions can be compared on identical numbers. Monte Carlo then uses its own repeatable stream. Statistically sound for simulation, not meant for security.
Fairness check
Over long runs the results match the true house edge: 2.70% on the European wheel (1/37), 5.26% on the American wheel (2/38), 7.89% on the American five-number bet, and 1.35% on even-money bets with La Partage or En Prison. "Expected (house edge)" shows turnover × edge; the actual result moves around it by luck.
Monte Carlo
Plays thousands of full sessions (one bank until the target or until it runs out). Rates are shown with 95% confidence ranges, so you can see how sure each number is.
What the simulator assumes
Stakes are whole units (minimum 0.10). Table limits are typical online values, real casinos differ. The progression table counts a partial win (something hit but the round still lost money) as a loss; the game itself pays it correctly. Real-time estimates use about 40 s per spin for a live online dealer and about 40 spins per hour at a casino table.
Privacy
Everything runs in your browser. Settings are saved only in this browser; nothing is sent anywhere.
Please note
This is an educational simulator. No betting system can change the house edge or guarantee a profit. 18+