Build a single-elimination bracket with automatic byes

Turn an ordered list of participant names into a complete single-elimination tournament structure. The bracket builder calculates the next power-of-two field size, inserts only the byes that are necessary, and labels every match through the final. No draw is randomized, so the same participant list always produces exactly the same bracket.

Prepare the participant list in seeding order

Start with at least two participant names and arrange them in the order you want the bracket to recognize. The first entry becomes seed 1, the second becomes seed 2, and so on. Names may identify individuals, teams, clubs, schools, projects, or any other competitors, but every entry must be a non-empty string.

Leading and trailing whitespace is removed so copied registration data does not create untidy labels. Duplicate names are preserved because two different competitors can legitimately share a display name; use qualifiers such as a city, division, or team code when readers need to distinguish them. The builder does not shuffle the field, consult rankings, or introduce randomness.

That deliberate behavior makes the output reproducible: identical input produces an identical match plan on every run. If registration order should determine placement, submit registration order. If rankings should determine placement, sort the names by ranking before calling the capability.

Keeping selection policy outside bracket construction makes the result easier to audit and lets each tournament apply its own published seeding rules without hidden assumptions.

Understand bracket size, matches, and byes

A single-elimination bracket works cleanly when its field size is a power of two: 2, 4, 8, 16, and onward. When the participant count falls between those sizes, the builder expands to the smallest power of two that can contain everyone. The difference becomes the bye count.

For example, five participants require an eight-slot bracket, so three seeded participants receive first-round byes and the remaining two play the opening contested match. Byes are assigned deterministically to the earliest seeds, while the remaining participants are paired in their submitted order. Each first-round match identifies its participant records by name and seed.

A bye match also identifies the participant who advances automatically. Later rounds contain source labels such as “Winner of match 1,” allowing a user interface or tournament system to connect results without guessing. Match numbers remain unique across the entire bracket.

The response also reports participant count, bracket size, bye count, and round count, which makes basic validation and display summaries straightforward.

Use the bracket in an event workflow

The returned rounds are ready to drive a bracket view, printable schedule, match database, or event operations checklist. Read rounds in ascending order and matches in their returned order. For opening matches, display participant names directly; when a match has a bye, advance the included competitor without requesting a score.

For later matches, replace each source label with the winner produced by the referenced match. The capability builds structure only: it does not collect scores, decide winners, schedule courts, resolve withdrawals, or reseed after a round. Those responsibilities should remain in the tournament application so its rules stay explicit.

A useful integration stores the generated bracket as the event’s initial immutable plan, then records results separately against match numbers. This preserves an audit trail even when a competitor withdraws or an organizer corrects a result. Validate the final participant list before publishing because changing its order changes the bracket.