crosseyed:
Great idea. In single elimination tourneys your seed number is determined by your rating. The total number of players need not be a power of 2.

The formula is: start off with 2 players. The 3rd player will play the 2nd and seed 1 will have a bye in the first round. 4th plays first. Adding a 5th will play the lowest seed, #4, and the higher 3 will get 1st round byes. Each additional seed will play the lowest seed with a bye in the 1st round until there is a power of two. the next lower seed after that will play the lowest seed and all others above will get byes for the 1st round. simple right?