Fixtures for 4 teams.

Round 1

1 v 4
2 v 3

Round 2

4 v 3
1 v 2

Round 3

2 v 4
3 v 1

Second half is mirror of first half

Round 4

4 v 2
1 v 3

Round 5

3 v 4
2 v 1

Round 6

4 v 1
3 v 2