What's the best tournament format: single elimination, double elimination or round robin?

Match the format to your number of entrants and the time you have. Knockouts decide a winner with the fewest matches. Round robins take longer but are fairer, because everyone plays the same number of matches. A group stage followed by a knockout sits between the two.

To estimate the time, divide the matches by your courts, then multiply by the match length plus changeover. Eight entrants in single elimination need 7 matches, which is four slots on two courts (two, one and one). A full round robin for eight needs 28 matches, or 14 slots.

Use these formulas, where n is the number of entrants (players, pairs or teams):

• Single elimination: n − 1 matches. Every match sends one entrant home, and all but the winner must go.
• Double elimination: 2n − 2 matches, or 2n − 1 if the final has to be replayed.
• Round robin: n(n − 1)/2 matches, or twice that if everyone plays everyone twice.
• Group stage + knockout: the matches in every group, plus one fewer than the number of qualifiers.

Round robins grow with the square of the field: double the entrants and the matches roughly quadruple. A 16-entrant round robin needs days or many courts; a 16-entrant knockout fits in an afternoon.

You are out after one loss, and the winners advance until one entrant is left. It is the quickest format. The number of rounds is log₂ n rounded up: 8 entrants play three rounds (quarter-finals, semi-finals, final) and 9 to 16 play four.

What if the number of entrants isn't a power of two?

The bracket grows to the next power of two, and the empty places become byes. An entrant with a bye skips round 1. With 11 entrants the bracket has 16 places, so 5 entrants get a bye and the other 6 play the 3 matches of round 1. That leaves 8 entrants for round 2, and the total is still 10 matches.

What is seeding?

Seeding ranks the entrants before the draw and spreads the strongest across the bracket. In a seeded bracket the top two seeds can't meet before the final, and the top four can't meet before the semi-finals. An unseeded random draw can put the two best entrants against each other in round 1. Flobit draws brackets at random and does not seed by rating, so tell your entrants the draw is blind.

Single elimination suits one-day events and big fields. Its weakness: one bad match, injury or no-show ends an entrant's whole event. If that matters to your group, choose double elimination or a group stage.

You are out after your second loss. Everyone starts in the winners bracket. Lose once and you drop into the losers bracket, where one more loss ends your event. The winners-bracket champion then meets the losers-bracket champion in the grand final.

The winners-bracket finalist has not lost yet, so some events make the other finalist win twice. That "bracket reset" is why a double elimination takes 2n − 2 matches if the undefeated finalist wins and 2n − 1 if a second final is played: 14 or 15 matches for 8 entrants, 30 or 31 for 16.

It gives a bad day a second chance, but it needs about twice as many matches as single elimination. It also works best when the field is a power of two, because byes complicate the losers bracket.

In Flobit, double elimination needs 4, 8, 16 or another power of two entrants, and the grand final is a single match, so an 8-entrant event has 14 matches.

In a round robin everyone plays everyone, and the table decides. With n entrants there are n(n − 1)/2 matches, played over n − 1 rounds if n is even and n rounds if n is odd, when one entrant sits out each round. Nobody is eliminated by a single bad match, and everyone plays the same number of matches, which makes it the fairest format.

The price is volume. Six entrants play 15 matches, eight play 28 and twelve play 66. A round robin works best with 4 to 8 entrants, or for a league played over several weeks. If everyone plays twice (a double round robin, often called home and away), the matches double.

A table needs a tie-break rule agreed in advance. The round robin schedule guide has the circle-method tables and the tie-break orders, and the round robin generator builds a schedule for you.

Entrants are split into groups. Each group plays a small round robin, and the top finishers go through to a knockout. You keep the fairness of a round robin in the first stage and the drama of a knockout at the end, and everyone gets several matches even if they lose the first.

The numbers have to fit. Groups × qualifiers per group should be a power of two (2, 4, 8, 16), so the knockout needs no byes.

Big events hit the same problem. The 2026 FIFA World Cup had 12 groups of four: two qualifiers each would make 24, not a power of two, so FIFA added the eight best third-placed teams to fill a round of 32. For a club event it is simpler to pick groups and qualifiers that multiply to a power of two.

In Flobit, group + knockout needs at least 6 entrants and at least 3 in every group. The qualifiers per group must be fewer than the smallest group, and groups × qualifiers must be a power of two. You pick both numbers when you generate the draw. With two qualifiers per group, each group's winner and runner-up go into opposite halves of the knockout, so group-mates can only meet again in the final.

Swiss

A Swiss tournament has a fixed number of rounds, and each round pairs entrants with a similar record. Nobody is eliminated and nobody plays the same opponent twice. Roughly log₂ n rounds, rounded up, are enough to find a clear winner: three rounds for up to 8 entrants, four for up to 16. Flobit does not create Swiss tournaments.

Mexicano and Americano

Both are padel social formats for individuals: points are tallied per person, and partners change. In an Americano everyone gets a new partner every round. In a Mexicano the next round is usually drawn from the standings, so matches stay close even in a mixed-level group. Flobit runs Mexicano, not Americano, and the organizer chooses whether each round is drawn from the table or every round is planned in advance. The Mexicano guide explains how, and the Americano guide covers the other.

King of the Court

Winners move up a court, losers move down, and whoever spends the most time on the top court wins. It fills a night with close games on several courts. Flobit has no King of the Court format.

Ladders

A ladder ranks players in a list. You challenge someone above you, and if you win you swap places. Ladders suit clubs that want matches all season without fixed dates, but someone has to keep the list honest. Flobit has no ladders; a league played over several weeks is the closest option.

Flobit runs five formats: single elimination, double elimination, league (a round robin played once or twice), group + knockout, and Mexicano for tennis, padel, table tennis and basketball. Tournaments run inside a community, with up to 5 at a time. You can cap entries from 2 to 512, approve each entry, keep a waitlist and invite pairs.

Know the limits before you plan:

• Random draw. Brackets, leagues and groups are drawn at random. Flobit does not seed by rating.
• Double elimination needs a power of two entrants, with a single grand final.
• Group + knockout needs at least 6 entrants, 3 or more per group, and groups × qualifiers equal to a power of two.
• Leagues are played once or twice. The table ranks by wins or league points, then by difference.
• Not available: Swiss, ladders and King of the Court can't be created. The free Americano generator makes Americano schedules on the web.

For brackets, leagues and groups the organizer flow is the same: close registration, generate the draw from the confirmed entries, then publish it. Players are notified when you publish. Tournaments in Flobit walks through the full setup.

What is the difference between single and double elimination?

Is round robin or knockout better?

How many matches are in a 16-player knockout?

What happens if the number of players isn't a power of two?

What is the fairest tournament format?

What is the best format for a one-day tournament?

Which tournament formats does Flobit support?