How Headspin keeps every pick fair

How it works

1. 1

   Add your names

   Type 2 to 16 names, or paste a whole list at once.

2. 2

   Choose a show

   Six games, from a UFO abduction to a knockout arena. Same fair odds in every one.

3. 3

   Press play

   The winner is drawn and sealed first, then the show reveals them.

1. The pick comes first

When a round starts, Headspin freezes the list of eligible names and draws the winner with your browser’s cryptographic random number generator (crypto.getRandomValues), using rejection sampling so there is no bias toward any position in the list. Every eligible name has exactly the same chance.

2. The show is a reveal

Each game is built so it can only end on the chosen winner. The marble race and knockout arena run real physics with identical bodies and assign the winner to the one that finishes first or survives. Plinko searches real drops for one that lands in the right slot. The Big Wheel plans its spin with real friction. The UFO and claw machine are choreographed to target the winner, with decoys picked at random from everyone else.

3. The seal proves nothing changed

At launch, Headspin shows a SHA-256 hash of the round, the winner and a random 128-bit salt. At the reveal, the Verify button shows the full sealed text, so anyone can recompute the hash (for example with shasum -a 256) and confirm the result was fixed before the show began.

The seal proves the result did not change during the show. It does not prove the draw itself was uniform; for that you are trusting Headspin’s code. Headspin is made for classrooms, teams and game nights, not regulated lotteries or prize draws.

Six ways to pick a name

• UFO AbductionA saucer drops out of the night sky over a sleepy farm, sweeps the crowd with its scanner, and beams up one lucky earthling.
• Marble Grand PrixEveryone gets a marble on a neon mega-track. Live standings, lead changes, and a photo finish decide who crosses first.
• Claw MachineA glowing prize cabinet packed with name capsules. The claw wobbles, feints, grabs — and drops one lucky capsule down the chute.
• Neon PlinkoA towering neon peg board. One chip, dozens of real physics bounces, and a slot with your name at the bottom.
• Big WheelA towering game-show wheel with chasing marquee lights and a flapper that clacks every peg — right down to the last teetering tick.
• Knockout ArenaEveryone drops into a floating arena. Hazards sweep, the floor crumbles, and bumpers fly until only one is left standing.

Questions