Guides

The wheels on this site pick. These guides explain how the pick is made and how the tools around it work — entry lists, eliminator mode, share links, segment geometry — so nothing is taken on trust. One small, pure engine runs every wheel, and it also wrote the numbers on these pages: each probability, angle, count and encoded link in a guide is computed at build time by the same code that runs the wheels, so the documentation cannot drift from the implementation. Where a guide walks through a draw, it feeds the engine a scripted sequence of bytes so the draw can be replayed exactly; a live spin takes its bytes from crypto.getRandomValues, the browser's cryptographically secure generator.

The methodology page states the whole mechanism in one place; the guides take it apart one rule at a time and name the common misreadings. The custom wheel on the landing page loads a sample list of 6 names: each occupies 60° of the circle and wins 16.67% of spins — computed at build time, not typed.

How the wheel picks a winner

The winner is drawn the instant you press Spin, before the wheel moves; the roughly four-second rotation is calculated to stop on a segment that has already won. The guide follows the draw byte by byte: the engine takes the minimal number of bits covering the entry count, masks away the excess, discards any candidate at or beyond the count and draws again — never a remainder, so every entry stays at exactly 1/N. Fed the scripted bytes 7 then 3 on the sample list, the engine drew 2 times: the first candidate fell at or beyond 6 and was discarded; the second gave index 3, Devon, landing at 210°.

Eliminator mode, explained

Tick eliminator mode and each spin removes the entry it picks; the last one standing is the overall winner. Every elimination is a fresh uniform draw over what remains — on a 4-chore list the chances run 1/4, then 1/3, then 1/2 — and each chore survives with probability exactly 1/4, or 25%. As a worked example, a scripted run of Dishes, Laundry, Bins, Vacuum eliminates in the order Bins, Laundry, Dishes, survivor Vacuum after 3 spins; the guide replays a full run of its own, spin by spin. It also covers why editing the list mid-run restarts the elimination, and why going out last is no better than going out first.

Is the wheel rigged? How to check

This guide lists what you can check rather than what you are asked to believe: the draw precedes the animation; a reduced-motion setting skips the rotation and announces the identical draw; the browser's network tab shows no request carrying your entries; rejection sampling leaves no modulo bias, and the automated tests drive every byte value through the mapping. It is equally plain about the limits: no auditor, no seed escrow, nothing to stop re-spinning until the result pleases.

Entry lists and parsing rules

A list is one entry per line, with one exception: a single line containing commas is split on the commas, so Alice, Bob, Carol becomes 3 entries, while the 2-line list beginning "Go out, or stay in?" keeps its comma and parses to 2. Whitespace is trimmed, empty lines are ignored, and a switch collapses case-insensitive duplicates to their first spelling. Entries are capped at 100, characters per entry at 80, and hitting either cap produces an honest error; nothing is silently truncated.

Segment geometry and colours

A wheel of N entries is cut into N equal segments, each one Nth of the circle, in list order, every boundary an exact multiple: 3.6° each on a 100-entry wheel, 180° each on the 2-face coin wheel. Colours cycle through a fixed palette of 8, adjusted on a 9-entry wheel — and on every larger size one past a multiple of 8 — so the last and first segments never match. The circle is drawn for the eyes; the winner is an index, and the rotation is computed afterwards to bring that segment's midpoint under the pointer. A 3.6° sliver on a 100-entry wheel is exactly as likely as a half-circle on a 2-entry wheel of equals — probability comes from the draw, not the drawing.

Copy share link percent-encodes each entry, joins them with | and places the result after #items= in the page address; the 4-chore list above encodes to 26 characters of a 1800-character cap on the encoded value, and the full address is 59 characters. Browsers do not include fragments in web requests, so opening a link rebuilds the wheel locally without sending the list to the hosting server. The guide also covers what stays on your device: edited lists in local storage, spins and history that die with the tab, and the one exit — a link you copy yourself.

Using the wheel for groups: classrooms, meetings, households

This guide is about mechanics, not about what a group ought to decide. Paste a roster of up to 100 names; tick the duplicate switch, so a 5-line roster with repeated names parses to 5 segments as typed and 3 with the switch on; turn on eliminator mode so each spin removes the name it picks and nobody is called twice before the list is exhausted, the last name standing being announced as the survivor; copy a share link so the same list opens on another screen; press Reset list to restore the preset. Each step stops where the mechanism stops: the wheel picks fairly among the names it is given, and nothing more.

Wheel versus coin versus dice

The coin flip wheel and the dice wheel are the same engine with 2 and 6 entries: heads or tails at 50% each, drawn from cryptographic random bytes with no launch side, catch or surface to favour, and each die face at 16.67%. Each spin is an independent draw, so a run of 5 heads comes to 3.125%. The guide sets out what a wheel adds over a physical coin or die (an editable list, eliminator mode, a share link) and what it does not: a uniform draw over whatever labels you give it, no more.

Where to start

If you came to spin, the custom wheel accepts any list up to the 100-entry cap, and the presets — Yes or No, Number, Food and the rest — are starting lists you can edit freely. If you came to understand the pick, read the guides above in order, then the methodology page for the mechanism in one piece; the about page says who the wheels are for and what the site is not.

For fun and tie-breaks: the guides explain how the wheels decide fairly, but the wheels cannot know your situation — do not delegate consequential decisions to them. Everything runs locally in your browser; see the methodology page for how the draw works.