Single elimination bracket generator.

How do byes and seeding work in a single elimination bracket?

A single elimination bracket works cleanly when the field is a power of two (2, 4, 8, 16, 32 …). For any other number of teams the bracket is rounded up to the next power of two, and the empty places are byes. The number of byes is 2^k − n, where 2^k is the smallest power of two that is at least n. A team with a bye advances without playing. This tool gives the byes to the top seeds, a common convention.

Standard seeding pairs the highest and lowest seed, the second highest and second lowest, and so on, so every first-round pairing adds up to the bracket size plus one (1 v 8, 2 v 7, 3 v 6, 4 v 5 in an 8-team bracket). The sequence is arranged so seeds 1 and 2 can only meet in the final.

Worked example. 6 teams: the bracket is 8, so there are 2 byes for seeds 1 and 2. Seeds 3 v 6 and 4 v 5 play in round 1, and the winners meet seeds 1 and 2 in the semifinals. Games = 6 − 1 = 5 because each game eliminates exactly one team.