Round-robin

In a round-robin, also called an all-play-all, each participant plays one game against every other participant. With n players, each player has n - 1 games and the tournament contains n × (n - 1) / 2 games in total.

The pairings can be fixed completely before the event starts because every required matchup is already known. Berger tables are a traditional method for distributing those pairings across rounds and assigning colors. With an odd number of participants, one player is idle in each round.

The main difference from a Swiss system is that everyone directly plays everyone else. This gives a very complete comparison inside the field, but the number of games grows quickly as more players are added. In a double round-robin, every pair meets twice instead of once.