Players 5 through 16 in turn randomly draw for TWO groups that they can move to, and then decide which one they want to join. The 16th player simply goes to whichever spot is left.
In part two, the four seeded players have to make a choice. Before the event the seeds 2-4 nominated a non-seeded player who was written on a golden ball. Now they have the right to:
Take that player to their group, giving back a player of their choice.
Take any other player (non-seed) to their group. This time, however, the seed-holder of the other group will decide who gets traded back.
The top seed (Flash) may finally choose to swap any player in his group for any player in another group, without the above restrictions.