How Many Matches Are in a Round-Robin League?

With n players, a single round robin contains n(n−1)/2 matches because every unique pair meets once. Four players create 6 matches; 8 create 28; 16 create 120. Adding players increases the workload quickly.

When every pair meets twice, the total is n(n−1). Four players create 12 matches; 8 create 56; 16 create 240. The return leg should continue the matchday numbering instead of restarting at Matchday 1.

With an even number of players, a single round robin normally has n−1 matchdays and every player can play once per matchday. With an odd number, it normally has n matchdays and one player receives a bye in each. A double round robin doubles the sequence.

Multiply matchdays by the duration of each round window, then allow time for unresolved results. A 16-player double round robin with 24-hour rounds has 30 matchdays before extensions—an ambitious month-long operation, not a weekend cup.