Round robin schedules, everyone plays everyone

What is a round robin tournament?

In a round robin, every team plays every other team. Nobody is knocked out after one bad game, and the final table reflects how everyone did against the whole field. That makes it the usual format for leagues, group stages, club ladders and social events where people want to play as many games as possible.

The trade-off is time. A knockout bracket for eight teams needs seven games; a round robin for the same eight needs 28. For small groups that is perfect. For large groups, split players into pools of four to six, run a round robin in each pool, then send the pool winners into a knockout bracket.

How many games and rounds does a round robin need?

The number of games is n times (n minus 1), divided by 2, where n is the number of teams. Four teams play 6 games, six teams play 15, eight teams play 28, ten teams play 45 and sixteen teams play 120. A double round robin, home and away, doubles each figure.

With an even number of teams you need n minus 1 rounds, and every team plays once in every round. With an odd number you need n rounds, and one team sits out each round. The generator prints that as "rests this round", so a seven-team league shows seven rounds of three games, with a different team resting each time.

How does the circle method build the schedule?

The circle method is the standard way to make a round robin by hand, and it is what this generator uses. Picture the teams sitting in two rows facing each other. Team 1 stays in its seat. Everyone else moves one place clockwise after each round. Each round, whoever faces each other plays.

After n minus 1 moves every team has faced every other team exactly once, and nobody has met the same opponent twice. For an odd number of teams, an empty seat is added, and whoever faces the empty seat rests that round. The generator also swaps which side team 1 sits on every other round, so the first team on your list is not always listed as the home side.

1. Write the teams in two rows: the first half on top, the second half underneath in reverse.
2. Pair each team with the one opposite: those are round 1's games.
3. Keep the first team fixed and rotate everyone else one place.
4. Repeat until you are back where you started.

How do you use the results grid and standings table?

The results grid is a table with every team down the side and the same teams across the top, numbered to keep it compact. Each square is one game. Write the score from the point of view of the team on the left, for example 3-1. The shaded diagonal is where a team would meet itself, so it stays empty.

In a double round robin, the row is the home game and the column is the away game, so the two squares for each pair hold two different matches. In a single round robin, you can fill in both squares for the same game, one from each side, which makes it easier to read across a row.

The standings table has columns for played, won, drawn, lost, scored for, scored against and points. Many leagues give 3 points for a win and 1 for a draw, but sports and clubs vary, so agree the scoring and any tie-breaker, such as head-to-head result or score difference, before the first game.

What helps a round robin run smoothly on the day?

• Print one schedule for each team captain and one large copy for a wall or noticeboard.
• Play the rounds in order, so a late team only misses its own games and not someone else's.
• If you have fewer courts or tables than games in a round, play the round in two waves and note the time next to each game.
• Keep the results grid with the organiser and fill it in as each game finishes.
• With an odd number of teams, use the resting team to referee or keep score.