Tie-breaking in Swiss-system tournaments

Swiss system tournaments, a type of group tournament common in chess and other board games, use various criteria to break ties between players who have the same total number of points after the last round. This is needed when prizes are indivisible, such as titles, trophies, or qualification for another tournament. Otherwise players often share the tied spots, with cash prizes being divided equally among the tied players.

Some tiebreakers used in other group tournaments are also used in Swiss-system tournaments, while others exploit the particular features of the Swiss system. If the players are still tied after one tie-break system is used, another system is used, and so on, until the tie is broken. Most of the methods are numerical methods based on the games that have already been played or other objective factors, while some methods require additional games to be played. In chess, where results are simply win/loss or draw, strength of schedule is the idea behind the methods based on the games already played: that the player that played the harder competition to achieve the same number of points should be ranked higher. In other games, results may supply more data used for breaking ties.