My earlier suggestion was to rank the players1, 2, 3, .....n.
Then deside how many groups there is going to be needed.
Then place the players, let say there are 85 players and 20 groups, the 20 highest ranked players first, one in each group, then the second 20 (ranked as 21-40) and place them in the groups in the reverse order, then the players ranked 20 and 21 end up in the same group. That is the "weakest" on the paper, but at least the most competitive.
Then place the players ranked 41-60 in the groups 1-20 respectively and then the player 61-80 in the reverse order again. When there are more players left like now, place the players 81-85 in the groups 1-5.