Tennis round robin formats for 4 to 16 players

A round robin is the fairest format there is. Everybody plays everybody, nobody is knocked out, and everyone goes home having played the same number of games. Clubs use it for social evenings, for the groups at the start of a championship, and for the boxes in a box league.

It is also easy to get wrong on the night. The numbers do not divide, two courts finish ten minutes apart, and three people end up level with nobody sure who won. This post is the arithmetic, done in advance.

Three kinds of tennis round robin#

Kind	Who plays whom	Suits
Singles	Every player plays every other player once	A box, a championship group, a small squad
Fixed pairs	Every pair plays every other pair once	A doubles event, a mixed doubles evening
New partner each round	Players enter alone and partner everybody once	Social tennis, club nights, a welcome evening

The third kind is the one most people mean by a tennis round robin at a club night. It is also the one whose numbers are hardest, because it needs groups of four on every court and every partnership to come up exactly once.

How many rounds and courts your numbers need#

For singles, an even number of players needs one fewer round than there are players, with every court in use. An odd number needs as many rounds as players, with one player sitting out each round. Six players play five rounds on three courts. Seven play seven rounds on three courts, and each sits out once.

For fixed pairs, it is the same rule with pairs instead of players. Four pairs play three rounds on two courts.

For a new partner each round, some numbers come out perfectly and some do not:

Players	Courts	Rounds	Sitting out each round	Comes out even
4	1	3	none	yes
5	1	5	1	yes
8	2	7	none	yes
9	2	9	1	yes
12	3	11	none	yes
13	3	13	1	yes
16	4	15	none	yes
6, 7, 10 or 11			2 or 3	no

“Comes out even” means every player partners every other player exactly once, faces each of them twice, and sits out the same number of times. With six, seven, ten or eleven players it cannot be done. Play a fixed number of rounds instead, spread the sitting out evenly, and accept that a few pairs never partner.

For any other number of players or courts, the free tennis round robin generator works out the rounds, the sitting out and how long it will take, in singles, fixed pairs or with a new partner each round.

How long a round robin takes#

Count the rounds, and multiply by the game length plus two minutes to change partners and ends.

Rounds	Ten-minute games	Fifteen-minute games
3	about 35 minutes	about 50 minutes
5	about an hour	about an hour and a half
7	about an hour and a half	about two hours
9	about an hour and three quarters	about two and a half hours
11	about two and a quarter hours	about three hours
15	about three hours	over four hours

Twelve or sixteen players will not finish a full round robin in an evening on fifteen-minute games. Either shorten the games, or play as many rounds as the evening holds and stop. Finishing on time matters more than finishing the schedule, because people judge the evening by whether it ran late.

Five players on one court#

The commonest awkward number at a club: five turn up for one court. Play five rounds with one sitting out each time. Everyone partners everyone once, plays against everyone twice, and sits out once. Give each player a number and read it off:

Round	On court	Sits out
1	1 and 2 v 3 and 4	5
2	1 and 3 v 2 and 5	4
3	1 and 4 v 3 and 5	2
4	1 and 5 v 2 and 4	3
5	2 and 3 v 4 and 5	1

On fifteen-minute games, it fills an hour and a half.

Eight players on two courts#

Eight players on two courts is the commonest club night of all. It takes seven rounds, everyone partners everyone once and nobody sits out. It is the same schedule a padel americano uses, and the printable version is in how to run an americano at your padel club. Only the scoring differs: count games won instead of points.

Singles: six players on three courts#

Five rounds, three matches each round, every court in use:

Round	Court 1	Court 2	Court 3
1	1 v 6	2 v 5	3 v 4
2	1 v 5	6 v 4	2 v 3
3	1 v 4	5 v 3	6 v 2
4	1 v 3	4 v 2	5 v 6
5	1 v 2	3 v 6	4 v 5

For any even number of players, the same pattern works. Write the numbers in two rows facing each other, keep player 1 still, and move everyone else one place round after each round. For an odd number, add a “sit out” as an extra player.

Fixed pairs: four pairs on two courts#

Three rounds, and every pair plays every other:

Round	Court 1	Court 2
1	Pair A v Pair D	Pair B v Pair C
2	Pair A v Pair C	Pair D v Pair B
3	Pair A v Pair B	Pair C v Pair D

Scoring a round robin#

How you score depends on whether the evening is social or a competition.

Social, with a new partner each round: each player keeps the games their side won. A round that ends 6 games to 4 adds 6 to both winners and 4 to both losers. Everyone’s games count, even in a round they lost, and whoever has the most at the end wins.

A competition, singles or fixed pairs: count matches won, and keep the sets and games for the tie-break. If the matches are short, such as one set or a FAST4 set, many clubs count games won instead, because a close loss then still counts for something.

Whichever you pick, say it before the first round. Changing the scoring at the end, when somebody can work out who it helps, is the one thing that will spoil an evening.

Tie-break rules for a round robin#

Agree the order before anybody is tied. Most clubs use this one:

1. Matches won.
2. The result between the tied players, if two are level.
3. The percentage of sets won.
4. The percentage of games won.
5. A tiebreak on court, or a coin toss if there is no time.

If three or more are level, look only at the matches between those players for step 2. If that separates one of them, go back to step 2 for the two still level.

Use percentages rather than totals when not everyone played the same number of matches. A player who sat out once should not lose on games to one who played every round.

For a social evening scored on games won, a tie is simplest left as a tie. Share the prize, or play one tiebreak while everyone watches.

Finishing on time matters more than finishing the schedule.

Running the evening#

Before: count the players who have said they are coming, pick the schedule, and book the courts for the whole evening. Print the schedule large enough to read from the court, or post it in the group chat.

At the start: give everyone a number, read the scoring and the game length aloud, and start the first round on time even if one person is late. They can join at round two.

During: use a whistle or a phone alarm if the games are timed, so every court changes together. Somebody collects the scores after each round.

At the end: read out the top three, and post the full table in the group chat. People like to see where they finished, wherever it was.

Round robin groups for a club championship#

A round robin also makes a good first stage for a club championship. Put the entries into groups of three or four, play a round robin in each, and send the top one or two from each group into a knockout. Everyone gets at least two or three matches, and nobody goes home after one. How to make a tournament draw with byes covers the knockout half.

When you run one every week#

For a one-off, the free tennis round robin generator deals the whole evening for any number of players and courts, and keeps the table. A round robin on paper works well once. Run one every week and the paper becomes a job. Somebody works out the schedule for whoever turns up, then collects the scores and adds them up before anyone can go home. A social night in Clayside deals each round for whoever is there and spreads the sitting out. It keeps the table as the scores go in, so the evening runs from one screen.