I think I figured this out

I think pairings are made somehow based on when people entered tournaments.

For example, in a quartets tournament, I think the people who entered the tournament 45th, 46th, 47th and 48th are all put in the same group.

Originally posted by Dutch Defense
I think pairings are made somehow based on when people entered tournaments.

For example, in a quartets tournament, I think the people who entered the tournament 45th, 46th, 47th and 48th are all put in the same group.

Coincidence.

http://www.playtheimmortalgame.com/help/index.php?help=tourn

Pairing
This may either be 'Original' or 'Random'. In a 'Random' tournament players are allocated between groups randomly. In an 'Original' tournament players are distributed by rating between the groups so the best rated players do no meet until later rounds.