Chess Tournament Pairing Generator - Swiss System
Generate Swiss-style pairings for a chess club tournament. Pair players by current score, avoid rematches, run the right number of rounds for your field size. Tool pre-loaded for 16 players Swiss; change the player count to match your event.
Swiss Pairing Rules (Plain English)
Core Pairing Rules
- 1.Round 1 pairings: top half vs bottom half by initial rating (Player 1 vs Player 9 of 16, Player 2 vs 10, etc.) or random for casual events.
- 2.From Round 2 onwards: pair players with the same current score. Within a score group, pair top half vs bottom half.
- 3.If a score group has an odd number of players, one player floats up (paired with the lowest player in the group above) or down (paired with the highest player in the group below).
- 4.No two players who have already played meet again.
- 5.Try to balance colours (each player gets roughly equal white and black assignments across the event).
- 6.If the total number of players is odd, one player per round gets a bye worth 1 point. No player gets two byes.
Typical Field Sizes and Rounds
The minimum is ceil(log2(N)) but most chess Swiss events play one extra round for a clearer winner.
Chess Swiss Tiebreaks
When players are tied on points at the end of a Swiss event, the standard tiebreak order (from FIDE Handbook section C.02.13 Tie-break Regulations) is:
- 1. Buchholz: sum of all opponents' final scores. Players who faced strong opponents score higher.
- 2. Buchholz Cut 1: Buchholz with the lowest opponent score discarded. Reduces the impact of an unusually weak draw.
- 3. Sonneborn-Berger: sum of beaten opponents' scores plus half of drawn opponents'. Rewards beating strong players.
- 4. Direct Encounter: head-to-head result among the tied players. Only applies if all tied players faced each other.
- 5. Number of wins: more wins beats more draws on equal points.
- 6. Average rating of opponents: when nothing else separates the players.
What This Generator Does Not Do
- - Full FIDE Dutch System pairing (Handbook C.04.3) with all tie-breaks, float restrictions, and absolute colour preferences.
- - Burstein System (C.04.4) used at some European events.
- - Accelerated pairings for the first two rounds (used in large opens to spread the top of the field).
- - Rating-based pairing within score groups (we pair top-half vs bottom-half within each score group; this is the simplified Swiss rule).
- - Colour-preference balancing for rated chess.
For FIDE-rated events use a FIDE-compliant pairing engine such as SwissSys, Vega, Swiss Manager, or Swiss-Perfect. Most national chess federations publish their preferred software. For unrated club events, casual chess nights, school chess club tournaments, and corporate chess events, simplified Swiss pairing works fine.