A physical roulette wheel can be subtly unbalanced. A deck of cards can be stacked. It's a fair question to ask whether a digital spinner wheel is actually random, or just looks like it. The short answer: it comes down to two things — equal-size slices, and where a genuinely random number generator picks the stopping point.
What "fair" actually means for a wheel
A spin is fair when every entry has exactly the same probability of being chosen. On SpinPick, each line you type becomes one equal slice of the circle — if you enter 8 names, each one gets exactly 45 degrees (1/8th) of the wheel, no matter the order you typed them in or how long the names are. Equal area means equal odds; that's the entire geometric half of fairness.
Where the actual randomness comes from
The other half is how the stopping point gets chosen. SpinPick uses your browser's built-in random number generator to pick a stopping angle uniformly across the full circle, then reads off whichever slice that angle lands in. Because the angle is drawn uniformly at random and the slices are equal in size, each entry has an equal chance of being the one under the pointer when the wheel stops.
You can weight the odds on purpose
Because every line becomes its own equal slice, entering the same name twice gives it two slices instead of one — doubling its chance of winning compared to a name entered once. This isn't a bug; it's a deliberate way to weight a wheel when you want one outcome to be more likely (for example, giving a bonus entry to someone in a raffle), while everyone else still has an equal, fair share among themselves.
Common myths about randomness
- "It's due to land on X" (the gambler's fallacy): Each spin is independent. If a wheel hasn't picked a particular name in five spins, that name is not "due" — its odds on the next spin are exactly the same as they always were.
- "It landed on the same thing twice, so it's rigged": With true independence, repeats are expected sometimes, especially with a small number of entries. Two spins in a row landing on the same name out of 4 options is not unusual — it's simply a 25% event on the second spin.
- "A bigger slice near the pointer at rest is more likely": The stopping angle is chosen before the animation plays out; the visual slowdown is just for effect and doesn't bias which slice was already selected.
Why this matters beyond curiosity
If you're using a wheel to settle something people care about — a raffle, a classroom pick, a work assignment — the fairness of the tool is the whole point. Understanding that the odds come from equal slices and a uniformly random angle (not from anything that can be nudged or predicted) is what makes the result something everyone can actually trust.