What happens when my entrant count is not a power of two?

The bracket expands to the next power of two and the empty slots become byes. Because the slots are filled in standard seeding order, the byes always fall to the highest seeds: eleven entrants in a sixteen-slot bracket give byes to seeds one through five. The page prints which seeds received them so nobody has to work it out from the drawing.

How many matches will a double elimination event actually take?

Two matches per entrant minus two, because every entrant except the champion must lose twice. Sixteen entrants means thirty matches, or thirty-one if the losers bracket finalist wins the first grand final and forces a reset. Single elimination is always one match fewer than the number of entrants.

Can I change a result after I have recorded it?

Yes. Click the other name in that match and the winner switches. Any later result that depended on the entrant you removed is discarded rather than silently reassigned, so the bracket never shows somebody advancing from a match they are no longer in.

Does a banded draw stop the two best entrants meeting early?

It stops them meeting before the final, provided your seeding is accurate. Seeds one and two are placed in opposite halves, seeds three and four in opposite quarters, and so on. It cannot protect against a seeding that is simply wrong about who is strong.

Tournament Bracket Generator

Paste your entrants, pick a format, and get a bracket that puts the byes where a real tournament puts them. Click a name to advance them; the losers bracket keeps up.

Entrants — one per line, best first if you are seeding

Format Draw Protected seeds Third-place play-off Grand final reset

Where the byes go, and why it matters

An elimination bracket only halves cleanly from a power of two, so 11, 23 or 40 entrants have to be padded. The bracket grows to the next power of two — 16, 32, 64 — and the leftover slots become byes. The question no free tool seems willing to answer is whose byes they are.

This page fills the slots using the standard recursive seeding order, the one built by repeatedly pairing seed s against seed n+1−s: 1 v 16, 8 v 9, 4 v 13, 5 v 12, and so on. Feed 11 entrants in and the five empty slots are seeds 12 to 16, sitting opposite seeds 1 to 5. The five strongest get the free pass, which is the point of seeding — a bye is a reward, not a lottery ticket. The summary line names those seeds outright, so you can check it rather than trust the picture.

The failure mode worth knowing about is a bye pile-up. If a tool drops byes at the end of the list instead of by seed, every bye lands in the bottom half of the draw and that half plays one fewer round of real matches than the top half. Half your field arrives at the semi-finals fresh and the other half has been grinding. Seeded placement spreads the byes across the draw as evenly as the numbers allow.

Three ways to fill the slots

As listed takes your line order as the seeding, so line 1 is the top seed. Random ignores the order completely and shuffles with crypto.getRandomValues, using rejection sampling so every position is equally likely rather than slightly favouring the low indices.

Random inside seed bands is how most real draws are conducted. Seeds 1 and 2 stay put in opposite halves. Seeds 3 and 4 shuffle between themselves, so both quarters get one but nobody knows which. Seeds 5–8 shuffle among their four positions, 9–16 among theirs, and everyone outside the protected group shuffles freely.

That gives a draw with genuine uncertainty that still cannot produce a first-round tie between the two favourites; the protected seeds control sets how deep it runs. Whichever draw you pick, the resulting order is written back into the entrant box, so the draw becomes the record — nothing hidden in a shuffle you cannot see.

Double elimination without the hand-waving

Choose double elimination and the losers bracket is wired to the winners bracket properly. Round-1 losers meet each other first; after that the rounds alternate between survivors playing each other and survivors facing the entrants just dropped from the winners bracket.

Drops enter in reversed order. Without that, the player knocked out of winners round 2 would land directly on the person they beat in round 1. The reversal removes those immediate rematches; it does not promise you will never see a repeat pairing later.

The arithmetic is fixed and worth planning around. Every entrant but the champion loses twice, so double elimination is 2N−2 matches: 30 for 16 entrants against 15 for single elimination. If the losers-bracket finalist wins the first grand final, both finalists have one loss and the title is undecided, so a second grand final is played — the bracket reset, on by default and switchable off if your schedule cannot absorb the extra match.

Recording results

Click a name and they advance. Click the other name and the result flips. Byes resolve themselves, so nobody has to click through a walkover. If you change a result that a later match depended on, that later result is dropped rather than quietly reassigned to whoever now occupies the slot — an unfinished bracket is easier to fix than a wrong one.

Results are held in local storage against the current entrant list, so a refresh mid-event does not wipe the day. Editing the entrants or the format rebuilds the structure and clears results, because the old match numbers no longer mean anything.

Questions that come up mid-tournament

What if two entrants withdraw after the draw?

Delete them from the list and rebuild. The bracket may shrink a size — 17 entrants need 32 slots, 15 need only 16 — which changes every match number, so do it before play starts if you can. Once matches are under way it is usually cleaner to leave the bracket alone and treat the withdrawals as walkovers, advancing the opponent with a click.

Can I run a bracket for 3, 5 or 6 entrants?

Yes, and small odd fields are where seeded byes matter most. Three entrants give a four-slot bracket with one bye, straight to the top seed. Six entrants give an eight-slot bracket with two byes, to seeds 1 and 2. The minimum is two entrants; double elimination needs at least three, and below that the page falls back to single elimination and says so.

How do I get this onto paper?

Press Print and your browser's own dialogue opens with the controls, this text and the ad placeholder suppressed — only the title, the summary and the bracket itself are sent. Landscape is requested automatically because brackets are wider than they are tall. A 32-slot double elimination bracket is a lot of paper; if it will not fit, reduce the scale in the print dialogue or print the winners and losers halves from separate passes by shrinking the browser window first.

Is the random draw good enough to be called fair?

For a club night or an office competition, comfortably. It uses the browser's cryptographic random source rather than Math.random, and rejection sampling keeps the shuffle uniform. What it cannot give you is evidence: there is no timestamp, no log and no witness, so a draw made in private proves nothing to anyone who was not watching the screen. Draw in front of the room, or accept that the result rests on trust.

What this tool does not do

No round-robin, no group stage feeding a knockout, no Swiss pairings — this is an elimination bracket only. There is no scheduling: it will tell you a match exists but not what time it starts or which court it is on. Scores are not recorded, only winners, so a bracket cannot double as a results archive. Entrant names are capped at 64 because a 128-slot double elimination bracket is not usefully readable on a screen or a sheet of paper. Everything happens inside the page after it loads; nothing about your entrants leaves the machine, and nothing is backed up anywhere except the local storage this browser keeps.