Run a Swiss tournament or bracket without the spreadsheet

1. Players

2. Format

Enter at least two players, choose a format and click Start.

Tournament

How it is built

Swiss pairing: players are ranked by score, then rating. Round one pairs the top half against the bottom half. Later rounds search for the whole round at once and choose the set of pairings with the lowest total cost, where a rematch is effectively forbidden, a score gap between opponents is expensive, and straying from the top-half-versus-bottom-half pattern inside a score group costs a little. An odd field gives the bye to the lowest-ranked player who has not had one.

Colours: with colour balance on, each pairing gives White to the player who is owed it, and a long run or a large imbalance adds to the cost so the search avoids it.

Tiebreaks: Buchholz, Buchholz cut 1, Sonneborn-Berger, wins and progressive score, in that order, then rating. Players level on everything share a rank and are marked as tied.

Brackets: standard seeding (1 v 8, 4 v 5, 2 v 7, 3 v 6), top seeds take the byes when the field is not a power of two. Double elimination drops each loser into the losers bracket in an order chosen to delay rematches, and the grand final can reset. Every match is derived from the results you have entered, so the bracket can never disagree with them.

Checked: the test suite plays out hundreds of random events, from 4 to 32 players: no rematches, one game per player per round, byes spread evenly, nobody out of a double elimination bracket before a second loss.

Common questions

How does Swiss pairing work?

Everyone plays every round and nobody is knocked out. Each round the players are sorted by score and paired with someone on a similar score who they have not played yet, so the leaders meet each other and the table sorts itself out in about log2 of the number of players rounds. Eight players need three rounds, sixteen need four.

How many Swiss rounds do I need?

Enough rounds that only one player can finish unbeaten: the next whole number above log2 of the player count. That is 3 rounds for 8 players, 4 for 16 and 5 for 32. One extra round makes the final ranking more reliable. The page shows the recommended number for your field.

What happens with an odd number of players?

One player gets a bye each round and is scored as a win unless you change the bye points. The bye goes to the lowest-ranked player who has not had one yet, so nobody gets a second bye before everyone has had one.

How are ties in the Swiss standings broken?

In this order: Buchholz (the sum of your opponents' scores), Buchholz cut 1 (the same with the weakest opponent dropped), Sonneborn-Berger (points scored against each opponent weighted by that opponent's score), number of wins, and progressive score. Players still level share a rank, and the page marks them as tied so you can run a playoff or apply your own rule.

Does it balance colours or home and away?

Yes, if you switch it on. The first player listed on each board is White or home. The pairing search penalises giving anyone the same colour three times in a row or a large imbalance, so over a six-round event nobody gets three in a row.

Can I run a single or double elimination bracket instead?

Yes. Choose the format and the page seeds the players by rating (or list order), gives the top seeds byes when the field is not a power of two, and lets you click the winner of each match. Double elimination has a winners bracket, a losers bracket and a grand final with an optional bracket reset. Change an earlier result and any later matches that depended on it are cleared.

Is my player list uploaded anywhere?

No. Everything is calculated in your browser, nothing is sent to a server and there are no accounts. Use Save tournament to keep a file you can load again later; nothing is kept on the page itself.