Single round robin is that all participating teams can meet once, and finally rank according to the points and gains and losses of each team in all competitions. If there are not many teams and the time and space are guaranteed, this kind of competition is usually adopted.

Single round robin means that each team has to play a game with other teams, and only one game can be played between each two teams. Suppose there are n teams playing a round robin. Each team needs to compete with other teams of n- 1. But this calculation will count every game twice (A to B and B to A are the same game). So the actual matching number should be n×(n- 1)/2. This is also the formula for calculating the number of matches in a single round robin.

The mathematical formula can be expressed as follows: the total number of competitions =n×(n- 1)/2, and 8 teams participate in the competition, which is substituted into the formula 8×(8- 1)/2=28.

Therefore, eight teams have 28 games in a cycle.