How stamps work.

Every pick is stamped when it is sent and opened when its game has settled, win or lose. Anyone can check that the pick we show is the pick we sealed. Check one now.

The problem

A service that shows its picks only after the games can show you anything it likes. A service that shows its picks while the games are being played gives away what its members pay for, and moves the price its members are trying to get.

We do neither. When we send a pick to members we publish a stamp. When the game is over we publish the pick and the key that shows the stamp was made from that pick and no other.

What you see

When a pick is sent

Second Line pick #214 stamped 2026-10-04 17:42:10 UTC · 8298edd408bc
Full stamp: 8298edd408bc66192805147d21f2d98e530577d2769794319fa47f62eea65e26

No game, no side, no price. The long line is the stamp. The short code after the dot is only a label for it.

When the game has settled

Pick #214 revealed.
NFL · SEA @ ARI · SEA +3.5 at DraftKings -110
Sent 2026-10-04 17:42:07 UTC · stamped 2026-10-04 17:42:10 UTC · 8298edd408bc
Won, +0.91u flat.
Check it yourself:
stamp 8298edd408bc66192805147d21f2d98e530577d2769794319fa47f62eea65e26
salt  00112233445566778899aabbccddeeff
pick  {"book":"draftkings","game":"SEA @ ARI","line":3.5,"market":"spread","pick_id":"example-1","player":"","price":-110,"side":"away","sport":"NFL","ts":"2026-10-04T17:42:07+00:00"}

That example is invented. Its numbers do verify: try it in the checker below.

How to check one

The stamp is a fingerprint (SHA-256) of the salt, a full stop, and the pick line, exactly as printed. Paste the three lines of a reveal here:

Or do it without us. On a Mac or Linux computer, paste this with the salt and the pick line from the reveal:

printf '%s' '00112233445566778899aabbccddeeff.{"book":"draftkings","game":"SEA @ ARI","line":3.5,"market":"spread","pick_id":"example-1","player":"","price":-110,"side":"away","sport":"NFL","ts":"2026-10-04T17:42:07+00:00"}' | shasum -a 256

It prints 8298edd408bc6619… If what it prints is the stamp we posted while the game was still being played, the pick in the reveal is the pick we sealed. Change one character of the pick (the side, the number, the price) and the fingerprint is completely different.

What this proves

1. The pick existed when the stamp was posted. The time on the stamp post is the platform’s clock, not ours.
2. We could not change it afterwards. Nobody can find a different pick that gives the same stamp.
3. We could not hide it. Stamps are numbered 1, 2, 3, … and every number is opened, win, loss, push or void. A missing number would be visible to anyone counting.

What it does not prove

• That you could have bet it. The price is the price the book was posting when we sent the pick. A live number can be gone in seconds. The record is graded at the posted price and says so.
• That the pick was good. A stamp shows when a pick was made. The record shows how picks did.
• Anything about a stamp you did not see posted. If you only ever see the reveal, you are trusting that the stamp was posted when it says. Follow the stamps as they are posted, or check the post’s own timestamp.

Why the salt

Without it, a stamp could be unmasked by trying every possible pick (there are only so many games, numbers and prices) until one matched. The salt is 32 random characters, different for every pick, kept private until the reveal.

Voided picks

A pick we void (a price that turned out not to be real, for example) is opened like any other, marked VOID with the reason, and left out of the totals in both directions. If it is voided after its result was posted, a correction is posted. Voiding removes wins as well as losses. Every voided pick is listed on the public record with its reason.

The public record →

21+. For information and entertainment. Second Line is an analytics service, not a sportsbook. Past results do not guarantee future results. You can lose money betting. Gambling problem? Call 1-800-GAMBLER.