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Single-elimination bracket — seeding, byes and how the draw is built

Updated 2026-09-05 · 3 min read

Single elimination is the format everyone recognises from a cup competition: lose once and you are out. It is the fastest way to find a winner from a large field and the format that produces the most drama, because every match is decisive.

The arithmetic of a knockout

Every match removes exactly one participant, and the tournament ends when one is left. So a single-elimination bracket with N entrants always has N − 1 matches, no matter how it is drawn. Sixteen players: fifteen matches. Sixty-four: sixty-three.

The number of rounds is log₂ of the bracket size. A bracket of 8 has three rounds (quarter-finals, semi-finals, final); a bracket of 16 has four; 32 has five; 64 has six.

Why the bracket size is a power of two

A bracket halves the field each round, so it only "fits" when the field is 2, 4, 8, 16, 32 or 64. With any other number, the draw is padded up to the next power of two with byes — empty slots that hand their opponent a free pass into round two.

Six entrants, for example, are drawn into a bracket of 8 with two byes. Two participants play their first match in round two while the other four play a round earlier. That is unavoidable in a knockout; the question is only who gets the advantage.

Seeding: who gets the byes and who meets whom

Seeding is the ranking you give participants before the draw. Seed 1 is the strongest. Two rules make a bracket fair:

1. Byes go to the top seeds. If someone has to skip a round, it should be the participants who earned it.
2. Top seeds are kept apart. Seed 1 and seed 2 are placed in opposite halves so they can only meet in the final; seeds 3 and 4 are placed so they meet the top two no earlier than the semi-finals, and so on.

The standard way to satisfy both is the 1-versus-N placement: in the first round seed 1 plays the lowest seed, seed 2 plays the second-lowest, and so on. For a bracket of 8 the slot order is 1, 8, 4, 5, 2, 7, 3, 6 — which is why, with six entrants, seeds 1 and 2 are the ones drawn against "seed 7" and "seed 8", the byes.

If you do not have a meaningful ranking, the order you enter participants is used as the seeding. Enter them in a random order if you want a random draw.

Third-place match

A pure knockout produces a winner and a runner-up, but the two semi-final losers are tied for third. When third place matters — medals, prize money, a qualification spot — add a third-place match between the two semi-final losers. It is played alongside the final and adds one match to the total.

Strengths and weaknesses

Single elimination is unbeatable on speed and simplicity, but it has two well-known weaknesses:

• One bad match ends your tournament. A strong participant eliminated in round one by a lucky draw or an off day never gets a second chance.
• It only ranks the top two reliably. Everyone eliminated in the same round is tied.

If either problem bothers you, the fixes are the double-elimination format (a second chance through a losers bracket) or groups followed by a knockout (everyone plays several matches before anyone is eliminated).

Build a bracket

In the bracket generator, choose Single elimination, type the participants in seeding order, and toggle the third-place match if you want it. Byes are placed automatically, winners advance into the next round as soon as you enter a result, and the whole bracket can be downloaded as an image for the group chat or the club noticeboard.