If there are many classes, you can draw lots for two teams to eliminate one team, and then divide them into two groups for intra-group circulation. Then take the first pair, the second pair, the first pair of the group, and then the two winning classes compete for the championship. Two unsuccessful classes competed for the third place. If there are only eight classes, you can also participate in the group competition directly.
A group match is a match between a class and all the other teams in the group. If the record is the same, it depends on who wins and who loses the two teams.