Direct Encounter is a TypeScript library implementing the Direct Encounter tiebreak for chess tournaments, following the FIDE Tiebreak Regulations (section 6). Zero runtime dependencies.
npm install @echecs/direct-encounterimport { directEncounter } from '@echecs/direct-encounter';
import type { Game, GameKind } from '@echecs/direct-encounter';
// Players A, B, C are tied on points
const players = [{ id: 'A' }, { id: 'B' }, { id: 'C' }];
// games[n] = round n+1; Game has no `round` field
const games: Game[][] = [
[{ black: 'B', result: 1, white: 'A' }], // round 1
[{ black: 'C', result: 0.5, white: 'A' }], // round 2
[{ black: 'C', result: 0, white: 'B' }], // round 3
];
const score = directEncounter('A', games, players);
// Returns A's score from games played against other tied players (B and C)FIDE section 6 — Direct Encounter score. Returns the total points scored by
playerId in games played only against other players in the players array
(the tied group). The caller is responsible for passing the correct subset of
players — typically those who share the same tournament score as playerId.
Byes are excluded. Round is determined by array position: games[0] = round 1,
games[1] = round 2, etc. The Game type has no round field. The optional
kind?: GameKind field identifies unplayed rounds; byes (black: '') are
excluded from Direct Encounter regardless.
directEncounter(playerId: string, games: Game[][], players?: Player[]): numberWhen all tied players have identical Direct Encounter scores (the common case in Swiss), this tiebreak is inconclusive and the next tiebreak in the ordering should be applied.
Contributions are welcome. Please open an issue at github.com/mormubis/direct-encounter/issues.