Eliminator mode, explained

The custom wheel and every preset wheel except the 2-entry pairs — coin flip, yes/no, go/stay and accept/decline — can run in eliminator mode. Tick the box under the result and the rules invert: the entry the wheel picks is removed instead of crowned, and the overall winner is whichever entry is left when every other has been eliminated. The pair wheels offer no toggle because the mode has nothing to add there: run through the real engine at build time, an elimination over Heads and Tails ends after 1 spin, with Heads removed and Tails the survivor — no more than a normal spin already reports. This guide explains what the engine does on each of those spins, why the mode is exactly as fair as a single spin, where it refuses to go, and how to read the result — with a complete elimination replayed step by step through the real engine. If you do not yet know how one pick is drawn, start with how the wheel picks a winner; the methodology page holds the full mechanism, and the guides page lists the series.

What eliminator mode changes, and what it does not

A normal spin draws one entry from the list and reports it. An eliminator spin draws one entry from the entries still remaining, in exactly the same way, and then removes it. The draw itself is unchanged: the same rejection-sampling routine reads bytes from the browser's cryptographically secure generator, maps them onto the count of remaining entries, discards any candidate at or beyond that count, and never takes a remainder. The pick is still made the instant you press Spin, before the rotation. What is new is what happens next: the picked entry leaves the list, the wheel redraws with the survivors, and the status line under the toggle reports how many remain and how many have gone.

The redraw is visible: start the 5-name list used below in eliminator mode and the wheel shows 5 segments of 72° on the first spin and 2 segments of 180° on the last. Those arcs are computed at build time by the engine's segment geometry and, as on every wheel, are for the eyes only: the width of a segment never enters the draw, the count does. Each remaining entry's chance on a given spin is one over that count, which for the list below runs 1/5, 1/4, 1/3, 1/2, read from the count of entries still on the wheel as each spin begins. When a single entry remains the engine marks the state finished, names the survivor as the winner, and the page disables Spin until you start over.

A complete elimination, replayed

Live spins read their bytes from crypto.getRandomValues, so no elimination can be reproduced on a page. The engine, however, lets its byte source be swapped for a script — the same device the automated tests use to pin exact behaviour — so the run below is a genuine elimination computed by the real engine at build time from the scripted bytes 14, 2, 3, 11, 0, 1. The list is 5 names written for this example: Priya, Marcus, Tomasz, Ines, Kofi.

The elimination order was Tomasz → Kofi → Priya → Ines; the survivor, and so the winner, is Marcus. Two details deserve a closer look. First, the engine read 6 bytes for 4 spins. The first byte read on spins 1 and 3 masked to a candidate at or beyond the number of remaining entries and was discarded; the next byte decided. A discarded byte contributes nothing: the engine's uniform pick over 5 entries returns 2 when fed the bytes 14 then 2, and 2 when fed only 2. That rejection step keeps every remaining entry exactly equally likely on every spin. Second, on the page each row appears as a result box — “Tomasz is eliminated”, with the survivors listed beneath — and as a line in the spin history; the final row reads “Winner: Marcus” and names Ines as eliminated last.

Why every entry survives with probability exactly 1/N

The methodology page states the guarantee: every entry ends up with probability exactly 1/N of being the survivor, where N is the number of entries you started with. Here is the reasoning in words. On any single spin the engine looks at one thing — how many entries remain — and draws an index uniformly over that count. It does not read labels, it does not know which entries are old and which were just added, and it gives every position the same chance. So on every spin, every remaining entry faces exactly the same risk of removal as every other. If no single step can tell the entries apart, no sequence of steps can either — and since exactly one entry survives, the equal shares of that one certain outcome are each one part in N.

A second way to see it: because each spin draws uniformly over whatever remains, every complete sequence of picks is exactly as likely as every other, so the engine can demonstrate the claim rather than assert it — replayed at build time down every possible path for the 5-name list above, counting who survives.

Each entry survives in exactly 24 of 120 equally likely paths, or 20.00% — the same figure as one over the 5 segments on the first spin. The per-spin chances rise as the list shrinks, 1/5, 1/4, 1/3, 1/2 in the walkthrough, but they rise identically for everyone still on the wheel, which is why no entry gains or loses by lasting long.

Where the engine stops

Eliminator mode needs at least 2 entries — a bound probed at build time by asking the engine, not typed. Ask it to start on a single entry and it refuses with “Eliminator mode needs at least two entries.” — with one entry the winner is decided before any spin. The cap is the same as on every wheel, 100 entries, enforced with the error “A wheel holds at most 100 entries.” rather than a silent trim.

Once a single survivor remains, the state is finished. Spinning again neither restarts it nor picks a new winner: the engine answers “This elimination is finished — reset to run it again.”, the page disables Spin, and the status line tells you to uncheck and re-check eliminator mode to run it again.

Editing restarts. Change the list while an elimination is running — add a line, delete one, switch duplicate removal on, press Reset list — and the engine begins a fresh elimination on the new list with everyone back on the wheel. The guarantee above holds for one fixed list, so half an elimination is never carried over to a changed one; the earlier spins remain only in the spin history, which keeps the most recent spins.

An elimination in progress lives on the page and nowhere else. The list you edit is saved in this browser's local storage so it survives a reload; which entries have been eliminated is not — reload and you begin again from the full list. Copy share link carries the list and only the list: the recipient's browser rebuilds the full wheel with eliminator mode off, never a half-finished run.

States are values, not a running tally

Inside the engine an elimination is a chain of immutable states: the entries remaining, in their original relative order; the entries eliminated, in elimination order; a finished flag; and the winner, set only when finished. A spin never modifies the state it was given — it returns a new one. After the 4 spins above were run at build time, the starting state still held 5 remaining entries and 0 eliminated. That is what lets the automated tests replay scripted sequences and assert every intermediate state, as the methodology page describes — and why the figures in this guide cannot drift from the wheel you use: both come from the same functions.

Three uses, mechanically

Dealing numbers without repeats. On the number wheel, eliminator mode turns the range into a deck: each spin deals one number and removes it, the survivor is the last number dealt, and the spin history shows the most recent deals. The history shows only the most recent spins and drops the oldest as new ones arrive, so on a long range the earliest deals have left it by the end — copy lines out as you go when the full order matters, as the groups guide advises. A run scripted at build time through the real engine over 1 to 4 with the bytes 1, 2, 0 took 3 spins and dealt 2, 4, 1, 3 — every number exactly once, the last needing no spin.

A week of dinners with no repeat. On the food wheel, trim the starter list to the ideas you want in play and switch eliminator mode on; each night's spin removes that night's dinner, so nothing comes up twice, and the elimination order is the week. Run at build time over the first 7 starter ideas with the scripted bytes 5, 0, 4, 3, 2, 1:

This is not a claim about food — the starter list is generic and meant to be edited — only what the mechanics do with a list of 7.

Assigning positions. On the custom wheel, put names in and read the elimination order as an order — first out speaks first, presents first or picks first, and the survivor takes the final position. From the walkthrough above that gives 1. Tomasz, 2. Kofi, 3. Priya, 4. Ines, 5. Marcus. Every ordering is exactly as likely as every other. If instead you want a single name — who gets the last slice, who takes the chore nobody volunteered for — the survivor is the answer and the order is incidental.

Reading the result, and common misreadings

“The first spin's pick won.” In eliminator mode the pick is the loser of that round. The result box says “is eliminated”, not “Winner”, until the final spin. In the walkthrough, Tomasz went out first; the winner was Marcus.

“An entry that has survived several spins is due to go.” Every spin is a fresh draw over what remains. A survivor's chance of being picked next is one over the remaining count, which is 50.00% on the final spin of the walkthrough, and it is the same for every other survivor. Nothing is owed and nothing carries over.

“Going out late is better than going out early.” There is no safe position: being removed on the first spin and being removed on spin 4 are both being removed. Only the last entry standing wins, and the tally above shows every entry is last equally often.

Frequently asked questions

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