WinCrib
Log in Sign up

Check a result

Work out any spin, roll or pool draw yourself. Everything runs in your browser.

Pool draw

Spin or roll

Find your revealed server seed in Profile → Fairness after changing seeds. Client seed and nonce are shown next to every roll.

The formulas

Rolls: HMAC-SHA256 with the server seed as the key and client_seed:nonce as the message. The first 8 hex characters as a number, divided by 4,294,967,296, give a roll between 0 and 1. The roll picks the prize from the published odds table.

Pools: HMAC-SHA256 with the pool seed as the key and pool_number:total_entries as the message. The first 13 hex characters as a number, modulo the total entries, plus 1, is the winning ticket.

Seed hash: SHA-256 of the seed. It matches the hash shown before you played, so the seed couldn't have been changed.