Formats

Every format takes participants in seed order, so the first one is the top seed. Ids must be unique. Each returns a new Stage with byes already resolved.

singleEliminationCopy Anchor Link

function singleElimination(participants: Participant[], options?: SingleEliminationOptions): Stage

A knockout bracket. Any number of participants works: when the field isn't a power of two, the top seeds get byes.

Throws a RangeError with fewer than two participants, and an Error when ids repeat.

singleElimination(teams, {
  thirdPlace: true,
  roundName: (index, total) => (index === total - 1 ? 'Championship' : `Round ${index + 1}`),
});

doubleEliminationCopy Anchor Link

function doubleElimination(participants: Participant[], options?: DoubleEliminationOptions): Stage

A winners bracket, a losers bracket fed by its losers, and a grand final. Produces groups {id}.wb, {id}.lb and, unless grandFinal is 'none', {id}.gf.

roundRobinCopy Anchor Link

function roundRobin(participants: Participant[], options?: RoundRobinOptions): Stage

Everyone in a group plays everyone else, once per leg. Groups are {id}.g1, {id}.g2…, of kind pool.

With groups: 2 and eight participants, snake seeding puts seeds 1, 4, 5 and 8 in group A and 2, 3, 6 and 7 in group B.

swissCopy Anchor Link

function swiss(participants: Participant[], options?: SwissOptions): Stage
function nextSwissRound(stage: Stage): Stage
function swissRoundsLeft(stage: Stage): number

swiss creates the stage with round one paired. Call nextSwissRound after every match of the current round has a result.

nextSwissRound throws when the current round has unfinished matches, or when every round has been played. Check swissRoundsLeft(stage) > 0 first.

fromRoundsCopy Anchor Link

function fromRounds(rounds: RoundInput[], options?: FromRoundsOptions): Stage

Builds a stage from data you already have. Rounds that halve in size are linked as a knockout tree and equal-sized rounds one to one. See Your own data.

RoundInputCopy Anchor Link

MatchInputCopy Anchor Link

ParticipantInputCopy Anchor Link

FromRoundsOptionsCopy Anchor Link