Tournaments · Swiss system
Swiss pairing calculator.
List players best seed first, pair round 1, record results, then pair the next round. No rematches, one bye per player.
Inputs
Pairings
Pair round 1 to begin.
How do Swiss pairings work?
In a Swiss-system tournament nobody is eliminated and nobody plays everyone. Each round, players with the same or similar score are paired, and no two players meet twice. The standard suggestion is about log2 of the number of players, rounded up, so 3 rounds for up to 8 players and 4 rounds for up to 16, which is usually enough to find a clear winner.
Dutch and Monrad. In the Dutch system the players in each score group are ranked and the top half is paired against the bottom half (1 v 5, 2 v 6, 3 v 7, 4 v 8 in round 1 of an 8-player event). In the Monrad system players are sorted by score and seed and paired down the list (1 v 2, 3 v 4 …). This tool does both, always skipping rematches by backtracking.
Byes. With an odd number of players one player sits out each round. This tool gives the bye to the lowest-ranked player who has not had one and scores it as a win (1 point), which is the usual scoring; events differ on who receives it. Nobody gets a second bye.
Limits. This is a simplified pairing for clubs and casual events. It does not balance colours or home and away, or follow the full FIDE Dutch rules, so for rated chess use certified pairing software and the FIDE rules.
Frequently asked questions
How many rounds should a Swiss tournament have?
About the base-2 logarithm of the number of players, rounded up: 3 rounds for up to 8 players, 4 rounds for up to 16, 5 for up to 32. More rounds separate the players further but run out of fresh opponents.
How are Swiss pairings decided?
Players are grouped by score and paired within the group, avoiding anyone they have already played. In the Dutch system the top half of a group plays the bottom half.
Who gets the bye in a Swiss tournament?
Rules differ by event. A bye is usually scored like a win and a player should not get a second one. Here it goes to the lowest-ranked player without a bye and scores 1 point.
What if no pairing without a rematch exists?
The tool says so. This happens when you play too many rounds for the number of players; stop earlier, or allow a rematch by hand.
Is this FIDE-compliant?
No. It follows the common Dutch and Monrad ideas but is not a certified implementation of the FIDE Dutch system.
Sources
Checked
Wikipedia gives the round count (binary logarithm of players, rounded up), the rule of pairing similar scores with no rematch, the Dutch top-half v bottom-half and Monrad adjacent methods, and bye handling (usually scored as a win, not repeated). The FIDE link is the official rulebook for rated chess; this tool is a simplified pairing, not an implementation of it. Runs entirely in your browser. Nothing you type is sent or stored.
Scope
A planning aid for casual and club events. Check your own league or federation rules for official formats, seeding, tiebreakers and pairings.