# How to fill out a bracket with byes

It’s making my head hurt trying to work out how the IFPA set up this 32 player bracket with 1 and 2 byes for top qualifiers. What is the principle that is used to enter byes into a Challonge bracket like this one?

http://challonge.com/ifpa14

I am confused because there are 32 players and yet player names such as bye 24, bye 25 etc.

Paging @Shep … He built the bracket for IFPA and I still have no idea how

If you act like you’re filling out the correct bracket with byes and double-byes, you’re backfilling the bye spaces to handle all the empty space. If you imagine a standard 24-player bracket (with 8 byes) it is not too far away from that.

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If you’re doing a bracket with byes and double byes where a quarter of the players get double byes, a quarter get single byes, and half get no byes, it works out neatly. So assume that the number of players is 4, 8, 16, 32, 64, etc. The way you form the bracket is to start with a bracket for double the amount of people you have, e.g. with 32 players, use a bracket for 64 players. Call the number of players who get either one or two byes N, so you have 4N players in total. Then put your double-bye players in positions 1 through N of the bracket, single bye players in positions N+1 through 2N, and no-bye players in positions 2N+1 through 3N and 5N+1 through 6N.

The simplest case is if you have 4 people, i.e. N=1, for which the standard 8-player [2N] bracket is:

Round 1:
1 vs. 8; 2 vs. 7; 3 vs. 6; 4 vs. 5

Round 2:
1/8 winner vs. 4/5 winner
2/7 winner vs 3/6 winner

Round 3:
Winners of round 2 matches.

In this case, you populate positions 1,2,3 and 6 per the above formula with the players in order of bye seeding: Double-bye #1 seed goes to slot 1, single-bye #2 seed goes to slot 2, no-bye seeds 3 and 4 go to slots 3 and 6. All of the other slots just say “bye” and the player opposite it gets a bye. Here, the only game in round 1 is seeds 3 and 4 playing each other in the 3 slot vs. the 6 slot; seeds 1 and 2 do not play, since slots 7 and 8 are empty. In round 2, seed #2 plays the winner of the 3 vs. 6 slot match. In round 3, seed 1 plays the winner of round 2. Seed 1 thus got their double-bye, and seed 2 their single bye.

In the IFPA case, with 32 players [N=8], you use a 64-player bracket and populate slots 1-8 with double byes, 9-16 with single byes, and 17-24 and 41-48 with no-byes.

If you don’t have a power of 2 number of players, it gets messier but can still be done.

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Here were the instructions I got from Shepherd:

Player list:

PUT TOP 24 HERE
bye25
bye26
bye27
bye28
bye29
bye30
bye31
bye32
bye33
bye34
bye35
bye36
bye37
bye38
bye39
bye40
PUT FINAL 8 HERE
bye49
bye50
bye51
bye52
bye53
bye54
bye55
bye56
bye57
bye58
bye59
bye60
bye61
bye62
bye63
bye64

Copy the “64 players” into Challonge’s bulk add feature

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