The Swiss system, explained in practice

The Swiss system is by far the most widely used format in amateur tournaments, from club events to regional championships. Unlike a round-robin, it lets a large number of participants play in relatively few rounds, without ever eliminating anyone along the way.

The principle, round by round

In round 1, players are usually split by Elo rating: the top half faces the bottom half. From round 2 onward, the principle changes: each player faces, as much as possible, an opponent with the exact same score, or the closest available score.

A concrete example

Take a 32-player tournament over 5 rounds. After round 1, the players on 1 point (the winners) are paired against each other in round 2, and likewise for those on 0. After round 2, you'll have one player on 2 points, several on 1, and others on 0: each score group is paired within itself as much as possible. Pairing software generally avoids matching the same two players twice.

Tiebreaks when players are level

Several players often finish a tournament tied on points. The final ranking is then decided by mathematical tiebreak criteria, the most common being Buchholz: the sum of the final scores of every opponent faced. The idea is simple, having faced tougher opponents overall counts in case of a tie.

What to know before your first Swiss tournament

• ✓Each round's pairings are posted shortly before it starts, not in advance
• ✓A player may receive a "bye" (a point with no opponent) if the number of participants is odd
• ✓It's normal, and even likely, to never face the top or bottom player in the standings
• ✓Winning your games mechanically raises the strength of your future opponents

Key takeaways

• ✓The Swiss system pairs players with a similar score each round, without elimination
• ✓It lets a large number of participants play in relatively few rounds
• ✓Buchholz (the total score of opponents faced) breaks ties at the end of a tournament