Swiss Tournament Rounds Calculator: Rounds, Records for the Top Cut and Schedule

How it works

Swiss rounds = ⌈log₂ N⌉ (+1 for a clear top 3, +2 for a top 8 ranked by Swiss alone; before a top-8 playoff: 5 rounds for 9–32 players, 6 for 33–64, 7 for 65–128, 8 for 129–226, 9 for 227–409, 10 for 410+, per the Magic Tournament Rules); expected players with w wins after R rounds = N × C(R, w) ÷ 2^R; knockout: N − 1 games over ⌈log₂ N⌉ rounds, 2^⌈log₂ N⌉ − N byes; double elimination: 2N − 2 games (+1 if the final is reset); round robin: N(N − 1) ÷ 2 games over N − 1 rounds (N if odd); time = sessions × round length + breaks, sessions per round = ⌈games ÷ boards⌉

A Swiss tournament pairs players with the same or similar scores each round and never eliminates anyone. Each round roughly halves the group still on a perfect score, so a single unbeaten leader emerges after log₂ N rounds, rounded up: 4 rounds for up to 16 players, 5 for up to 32, 6 for up to 64. Ranking the places below first by Swiss alone takes a round or two more. If the top eight go on to a knockout playoff, the Swiss part only has to find those eight, so card-game events follow the Magic Tournament Rules table instead: 5 rounds for 17–32 players, 6 for 33–64, 7 for 65–128. With an odd field one player gets a bye each round; under the FIDE rules it scores like a win and nobody gets two. The expected standings table shows how a field spreads out if every game has a winner and players are evenly matched: after R rounds the share on each record follows the binomial distribution. Card-game and esports players use this to see which record (for example 4–1) is likely enough to reach the top cut. Draws, intentional draws and uneven fields move the line, so treat it as a guide. The calculator then turns rounds into a timetable from your round length, breaks and the number of boards. When there are fewer boards than games, each round runs in several sessions. For comparison it shows a single-elimination bracket (fewest games, but half the field is out after one match), double elimination (everyone gets a second chance) and a full round robin, which is the fairest but grows with the square of the field.

Worked example

For 24 players, ⌈log₂ 24⌉ = 5 because 2⁵ = 32 ≥ 24, so 5 Swiss rounds find a winner. That is 12 games per round and 60 in total. Twelve boards cover each round in one session, so the event takes 5 × 60 + 4 × 10 = 340 minutes = 5 h 40 min and, starting at 09:00, ends about 14:40. After 5 rounds we expect 24 ÷ 32 = 0.75 undefeated players, so a single perfect-score winner is likely. A knockout would need 5 rounds and 23 games with 8 byes; a round robin 276 games over 23 rounds.

Sources: Swiss-system tournament (Wikipedia) · FIDE Handbook C.04.1: basic rules for Swiss systems

Frequently asked questions