How to determine the ranking of 13 teams in single round robin system

If it is a round robin system, each team plays 12 games, and the ranking is determined by points, goal difference and number of goals.

Elimination system, the first round draws lots to produce 1 team, after the first round draws lots to produce the winning 6 teams and bye teams for elimination system, and bye also has 1 team. In the third round, the remaining four teams can catch the match according to the positions determined in the last round, or draw lots to determine the opponents in the semi-finals and finals.

If it is a group match plus elimination match, it can be divided into four groups, one with four teams and the other with three teams. The group draws lots to decide that the top two groups qualify and enter the quarter-finals elimination tournament.