Final system
The first round: double round robin, in which 12 teams are randomly divided into four groups with three teams in each group, and the BO 1 match is played in their own group. The winning team will get a point, and the losing team will not get a point. After that, the two teams with the most points in each group will enter the next round, and the team with the least points in each group will be eliminated directly.
The second round: random pairing, the other eight teams are randomly paired, and the first and second place in each group draw lots respectively. In the second round, the first place in each group played against the second place in each group, and the winning team after BO5 entered the group stage for confrontation.