BIG BAD WOLF, the procedure is much simpler than that:

- Take the maximum number of players per section as designated by the tournament creator
- Take one away
- Multiply by the number of time each pair will play
- Voila, the absolute maximum number of slots needed!

Surely that maximum number of players per section is stored somewhere, the max slots needed is just (that number-1)x2, nothing computationally intensive! And this can be done before kicking players starts. If they simply do not have this necessary number of slots, EVEN if they might eventually need less, they are kicked! This way, we can be sure that people can continue playing to their maximum 20 slots all the time, not reserve extra slots that will NEVER be needed by a tournament...