Useful Drawer

Is a Yes or No Wheel Actually Random?

The result is chosen before the wheel moves, and the spin just delivers it — so nothing about how you click can bend it. What pseudorandom means here, and why six slices are still even odds.

·4 min read

A spinning wheel raises a fair question: is the result decided by physics, by how hard you spun, or by nothing at all? On a well-built one the answer is none of those. The result is chosen before the wheel moves, and the spin is an animation delivering it.

Where the answer actually comes from

A browser wheel does not simulate a spin and read off where friction stopped it. It picks the outcome first — using the browser's own random number generator — and then calculates a rotation that finishes on that slice. That order matters, because it means nothing about your input can bend the result. How long you hold the button, how fast you click, whether you spun a second ago: none of it is an input to the draw.

Why the odds are still even with six slices

The Yes or No Wheel shows each answer three times, alternating around the rim, rather than splitting the circle in half. That is a legibility choice — a two-slice wheel barely reads as a wheel and spins badly — and it changes nothing about the probability. Yes holds three of six slices and no holds the other three. Adding the maybe option moves it to two of six each, still equal.

"Random" in a browser, precisely

The generator behind this is pseudorandom: a deterministic algorithm seeded from the environment, not radioactive decay. For settling whether to order the pizza, that distinction is academic — the output is uniformly distributed and unpredictable to anyone watching. It would matter if you were running a lottery or generating encryption keys, and neither is what a decision wheel is for. Being straight about that is more useful than claiming perfection.

The thing a wheel gives you that a private choice cannot

Fairness that nobody can audit is worth less than fairness everyone watched happen. The reason to spin in front of the room is not that the browser is more impartial than you are — it is that the room saw the same wheel you did, and nobody has to take your word for the outcome. That is also why the wheel goes full screen and why a name picker works the same way: the visible draw is the point.

Best of three

Every spin is independent, so a run of three yeses is neither a malfunction nor a message — with even odds it happens one time in eight. The running count exists because people genuinely want best of three, not because any single spin needs correcting.

Something out of date or wrong here? Device specs and interface details shift with every release. Tell me and I'll fix it.

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