Roulette: one float, 37 pockets
How a Stake-scheme European Roulette spin picks a pocket from one float, and why the house edge is fixed by the wheel at 1/37 rather than by a formula.
Disclosure: VerifyRoll is sponsored by Craze, a competitor of the operators whose published RTP appears below. Figures here are computed or taken from what operators publish, dated; nothing is estimated.
How the result is derived
Under the Stake scheme every result starts from HMAC-SHA256(server seed, “clientSeed:nonce:cursor”), read four bytes at a time into floats in [0, 1). Roulette consumes one float.
- Take the first float from HMAC-SHA256(server seed, "clientSeed:nonce:0").
- Multiply by 37 and drop the fraction: a pocket from 0 to 36, each with probability exactly 1/37.
pocket = floor(float × 37)
Payout rule and where the edge comes from
Payouts follow the standard European table (35 to 1 on a single number, 1 to 1 on red/black and so on), but the table is the operator's to publish; check the rules panel of the game you are playing.
Every standard bet pays as if there were 36 pockets while there are 37. That single zero is the whole edge.
Source of the edge. Fixed by the wheel: 1/37 = 2.70% on every standard bet. No formula factor is involved, so the published RTP is 97.3% rather than 99%.
Worked example
Computed on the server by the same functions the verifier runs, from the example values the verifier's “Load example values” button uses. These are not seeds from a real round.
- server seed
- 2b4d2f1a7c9e0f3b8a6d5c4e3f2a1b0c9d8e7f6a5b4c3d2e1f0a9b8c7d6e5f4a
- client seed
- verifyroll
- nonce
- 7
- HMAC-SHA256(server seed, “verifyroll:7:0”)81727d41db6b44706ddfd681ab9cd0124cc482392adbbdda8ac8ac626566bf1a
- Float (1): 0.50565322
- float = 0.5056532176677138
- pocket = floor(float × 37) = 18
Published RTP by operator
| Stake | Shuffle | BC.Game | Craze |
|---|---|---|---|
| 97.3% | 97.3% | 97.3% | — |
Fixed by the wheel: 1/37 house edge = 2.70%. Checked 2026-09-23. “—” means not offered or not published. The figure in your game's info panel wins.
Questions
- Is red/black a 50% bet?
- No. 18 of 37 pockets are red, so the chance is 48.65%. The streak calculator has a preset for it.
- Why is the RTP lower than the other Originals?
- Because the payouts are the traditional ones and the wheel has a zero. Operators could pay more than 35 to 1 to reach 99%, but they publish the classic table.
Next
- Losing-streak odds on red/black (18/37)
- Verify a Roulette bet of your own, or by operator: Stake Roulette verifier · Shuffle Roulette verifier
- House edge for every game and operator
last reviewed 2026-09-23 · derivation as implemented in @craze/fairness