We need to have Evo-style brackets.
Here's the tl;dr:
The total number of entrants is split into typically four separate pools. After appropriate seeding, a standard double elimination tourney is run for each pool. The pool is run until a top four is obtained, with two on the winners, two on losers.
Assuming the tourney had four pools, the tourney would be whittled down to eight losers and eight winners. Then, a standard DE bracket is done and we get a winner.
The good thing with this format is that you can change how many entrants get to the main bracket, and it runs faster (pot monsters only play twice, as opposed to 4-7 times with pools.)
If you have questions, ask me. I'm on aim, so blow it up. (On FB as well.)