Provably Fair Deals
The oldest complaint about online sheepshead is "the deal is rigged." At Sheepshead Club you do not have to take our word that it is not. Every shuffle is locked in with a cryptographic commitment before any cards are dealt, and the proof is revealed when the hand ends. Anyone can check it, and the game does it for you with one click.
The short version
Each hand is dealt from a secret: 256 random bits, written as 64 hexadecimal digits, picked by the server when the hand starts. The same secret always produces the exact same deal, so the secret is the whole shuffle. The trick is proving we picked it honestly, before we could see anyone's cards. We do that with a commit-and-reveal:
sha256 hash of it (mixed with the table and hand number). You can see this hash on the table the moment the hand begins, before a single card is played. A hash is a one-way fingerprint: it locks in the secret without revealing it.If the revealed secret hashes to the commitment shown before the cards came out, the deck could not have been stacked, reshuffled, or peeked at. That is what "provably fair" means: not "trust us," but "check us."
Why so long? Older hands were dealt from a seed, a number below about two billion. Our dealing code runs in your browser, so in principle somebody could have tried every seed against the cards in their own hand until one matched, and then known everyone else's cards. Two billion tries is a lot, but a computer gets through it. Nobody gets through 2256, so the cards in your hand tell you nothing about anyone else's. Hands dealt from a seed, and practice deals somebody chose on purpose (the test-a-rule links and the lessons), still verify exactly as they always did.
Verify it yourself, in one click
When a hand ends, the table shows the revealed secret (or, on an older hand, the seed) with a Verify deal button. Click it and Sheepshead Club, running entirely in your own browser:
- recomputes the
sha256commitment from what was revealed and checks it against the hash that was published before the hand, and - replays it through the same dealing code to reproduce every hand at the table, so you can see the deal was exactly what it produces.
A green result means the math checks out. None of this is sent back to us; the verification happens on your device against numbers you were shown.
Doing it by hand
For the truly skeptical, the commitment is plain sha256 of v2:tableId:handNum:secret. Take the secret and the table and hand identifiers shown on the table, hash that string with any sha256 tool, and compare it to the commitment. It will match. On an older, seed-dealt hand the string is tableId:handNum:seed.
The deal is just as checkable. The secret is stretched into a stream of numbers: block 0 is the sha256 of secret:0, block 1 of secret:1, and so on, each block read as eight 32-bit numbers. Those numbers shuffle the 32-card deck, starting from our standard deck order, from the last position down: the card at position n swaps with the card at position (number mod n) + 1, counting from 1. A number from the very top of the range, which would make some positions a hair more likely than others, is skipped and the next one used instead. Then each seat gets a full hand in turn off the top, and the blind is next. The same secret always deals the same cards, and the Verify button does all of this for you.
Your own deals, against the odds
One honest hand does not answer a cold streak. So the game also counts your deals: how many trump and queens you were dealt, hand after hand, set beside what a shuffled deck gives on average, and how the people at the tables compare with the bots. See your deals vs the odds.
Nobody can pay for better cards, and supporter badges are cosmetic. Your own numbers are counted from the same sealed deals you can verify, as each hand ends, and kept on your account as running totals: counts only, never a list of hands, so the 7-day rule below still holds.
What we keep
Every hand is recorded, because that is what makes the fairness check possible after the fact and lets us audit how the bots actually play. The record is the deal itself: the secret (or seed) it was dealt from, the cards, who took what.
If you are signed in, hands you played are linked to your account for 7 days, so you can come back and look at a hand from another device. After 7 days that link is dropped and the hand goes back to being an anonymous record. Your account does keep running totals, such as how many hands you have played and how many trump you were dealt, but never which hands they came from. Play as a guest and no link is ever made; your history lives in your browser and nowhere else. The one exception is a club’s own tables: a club keeps a season record by default, and while it is on and the club keeps playing, a club member’s link to a hand at that club’s own tables is kept, for that club’s members only. The club’s owner can turn it off, which deletes it, and a year with no hands at the club’s tables deletes it too.
We do not sell this, and it is not used to build a profile of you. It exists so you can check the deal and so we can catch our own bugs.
We also keep a handful of plain counts, so we can tell whether a feature is working. (The feature in question is the coach.) For example: how many times the coach spoke up today, and how many times somebody switched it off. A count is a day, a name and a number. It carries no account, no hand and no session, so it can tell us that the coach was switched off nine times on Tuesday and it can never tell us who did it.
Why we bother
Most card sites ask you to trust an invisible shuffle. We think a game played for bragging rights, ladder position, and the occasional tournament prize deserves better than trust. Provably fair dealing is the one thing no amount of marketing can fake, and it is the clearest promise we can make: the cards you are dealt are the luck of the draw, nothing more. Free to play, no chips, no ads, and a deck you can audit. Read the rules, then pull up a chair.