What "committed before kick-off" means

Before a match starts we publish a fingerprint of the pick. After the day settles we publish the key to it, so anyone can check that the pick was not edited once the result was known.

How it works

• At release we take the pick's details — the date, the fixture, the market, the published price, the minimum price and the kick-off time — plus a secret string, and run the lot through SHA-256.
• That output, the commit hash, is published with the pick, before kick-off.
• Once the day has settled, the secret string is published too.
• Anyone can then recompute the hash from the published pick and check it matches. Change a single character of the pick and it does not.

Why the secret is held back

Because the hash would otherwise give the pick away. There are only so many fixtures on a card and so many markets on a fixture, so with the secret in hand a non-buyer could try combinations until one produced the published hash. Holding it until settlement keeps the paid product paid, and releasing it afterwards is what makes the record checkable.

What it proves — and what it does not

• It proves the pick you are looking at in the archive is the pick that was published, unedited, and that it existed before the match.
• It does not prove the pick was a good one. A bad bet hashes exactly as well as a good one.
• It does not make anything more likely to win. It is a record-keeping device, not an edge.

Extra picks are committed the same way, each against its own kick-off. A supporting pick published after the ball is in the air would be worth as little as a main one.