Round-robin
Everyone plays everyone. It is the fairest and longest format: with N teams, the matches are N × (N − 1) / 2, and the rounds required are N − 1 if N is even, N if it is odd (with one team resting each round).
| Teams | Matches | Rounds |
|---|---|---|
| 4 | 6 | 3 |
| 5 | 10 | 5 |
| 6 | 15 | 5 |
| 8 | 28 | 7 |
| 10 | 45 | 9 |
The growth is quadratic and becomes prohibitive very quickly: going from six to ten teams, the matches triple. With 45-minute slots and two courts, an eight-team round-robin takes more than ten hours. The practical conclusion: a single round-robin is fine up to five or six teams, beyond that you split.
The round-robin is also the right format when the tournament is played over several evenings: a six-team league among friends, one match each per evening, is five evenings and no one is left out.
Single elimination
You are out at the first defeat. With N teams, the matches are exactly N − 1, so it is the most economical format of all: sixteen teams fit into fifteen matches. The bracket is built on a power of 2 (4, 8, 16, 32); if the teams are not a power of 2, you need byes, i.e. rest rounds in the first round.
The number of byes is 2^k − N, where 2^k is the first power of 2 greater than or equal to N. With eleven teams: 16 − 11 = 5 byes, so five teams go straight into the round of 16. Byes are assigned to the seeded teams, otherwise they become a random gift.
The flaw is structural: half of the teams play only one match. In a tournament among friends, where people have given up their Saturday to play, this is a format to be used only for the final stage.
Double elimination
You are out after two defeats: whoever loses moves to a losers' bracket and can work their way back up. The matches are approximately 2N − 2 (one more if the final allows for a rematch). Sixteen teams: about thirty matches instead of fifteen.
It is much fairer than straight knockout and has a real advantage in amateur tournaments: no one goes home after half an hour. The disadvantage is that the schedule is not known in advance beyond the first round, so it must be managed by whoever is keeping the bracket in real time.
Groups plus final stage: the standard format
This is the one that in practice works for 90% of one-day tournaments. You divide the teams into short groups (preferably of 4), the top teams from each group qualify, and a knockout bracket is played.
A complete example with eight teams and two courts:
- two groups of 4: 6 + 6 = 12 matches;
- semi-finals between the top two of each group: 2 matches;
- final and third-place play-off: 2 matches;
- total 16 matches, each team plays at least 3.
With 45-minute slots on two courts, that is 16 × 45 / 2 = 360 minutes, which is six hours. Compare this with a single eight-team round-robin: 28 matches, over ten hours. Same perceived fairness, four hours less.
With twelve teams: three groups of 4 (18 matches), then quarter-finals with the top two from each group plus the two best third-placed teams (4 + 2 + 2 = 8 final stage matches), total 26 matches. With three courts and 45-minute slots: about six and a half hours.
Mixed formats worth knowing
- Single-set groups + best-of-three finals. Halves the duration of the group stage and keeps the matches that matter complete. The most common choice in summer tournaments.
- Single round-robin with play-offs. Everyone plays everyone, then the top four play for the title. It makes sense over several evenings, not in a single day.
- Swiss system. In each round, teams with the same number of wins face each other, for a fixed number of rounds. No one is eliminated, everyone plays the same number of matches, and the matchups balance themselves out. It requires someone to make the pairings between rounds.
- Rotating groups with timed scoring. Useful with a lot of teams and few hours: 15-minute matches, whoever is ahead at the signal wins. It is entertainment, not a competition: make this clear.
How groups are composed
If the teams have a known level, the distribution is done in a serpentine format: teams are ordered by strength and distributed in a zig-zag pattern among the groups. With four groups and sixteen teams, the order is:
| Tier | A | B | C | D |
|---|---|---|---|---|
| 1 | 1 | 2 | 3 | 4 |
| 2 | 8 | 7 | 6 | 5 |
| 3 | 9 | 10 | 11 | 12 |
| 4 | 16 | 15 | 14 | 13 |
Each group sums to 34: the groups turn out to be equivalent on paper. If the level is not known, a draw is held — and it is better to draw in front of everyone than to estimate poorly.
An arrangement that avoids half of the complaints: if two teams come from the same group of friends or the same club, put them in different groups. The match between them, if it happens, will happen in the final stage, where it does not decide who qualifies.
Choosing in three questions
- How many court hours do I have, for how many courts? From this comes the maximum number of matches.
- How many matches do I want the last-placed team to play? If the answer is "at least three", single elimination is ruled out.
- Who is keeping the bracket during the day? If no one can follow it in real time, avoid double elimination and the Swiss system: you need formats with a schedule known from the start.