There is simply no good way to schedule this arrangement of players. Below players 5 & 7 are particularly
unbalanced in terms of their opponents.
( 7 8 13) ( 2 12 4) ( 3 11 9) ( 1 10 6 5)
( 6 3 2) (12 11 1) ( 8 7 5) (13 9 4 10)
(13 1 3) (12 9 5) (10 7 2) ( 6 11 4 8)
(12 6 13) (11 10 5) ( 4 3 7) ( 8 9 1 2)
( 6 9 7) ( 2 11 13) ( 1 4 5) (10 12 8 3)
Hope that helps.