Bracket Generator
Turn a list of players into a single-elimination bracket that respects seeding, with byes given to the top seeds and top seeds kept apart until the final.
About this tool
A single-elimination bracket has one hard constraint: the number of slots must be a power of two. Every match removes exactly one player, so a bracket with 8 slots has 4 matches in the first round, then 2, then 1, and the total is always one less than the number of slots. Six players do not fit that shape, so the bracket is built for 8 and two players sit out the first round. Those two are the byes, and who receives them is the part that decides whether the draw is fair.
Seeding is not a decoration. The standard placement is built recursively: start with seeds 1 and 2 at the top of the two halves, then split each half again so that 3 and 4 land in the two quarters furthest from the top two, and continue until every slot is filled. For 8 players the order is 1, 8, 4, 5, 2, 7, 3, 6. That ordering guarantees three things: seed 1 and seed 2 can only meet in the final, seed 1 and seed 4 can only meet in the semi-final, and every seed faces the weakest possible opponent in the first round.
Byes follow from the same logic. The spare slots are the highest seed numbers, since those are the positions no player occupies, and each one is paired against a top seed. With 6 players in an 8-slot bracket, the empty positions are 7 and 8, which are paired against 2 and 1. So the top two seeds advance without playing. That is not a courtesy: it is what keeps the bracket balanced, because giving a bye to a low seed would hand an easy path to the player who is supposed to have the hardest one.
The seeding order is built by splitting halves
Start with 1 and 2 at opposite ends. Then split each half again, placing 3 and 4 away from the top two, and repeat. The sequence for 8 players is 1, 8, 4, 5, 2, 7, 3, 6.
The rule is easier to see backwards. In the final, the two remaining players come from the top half and the bottom half. So seeds 1 and 2 are placed in different halves. In the semi-finals, four players remain, one from each quarter, so seeds 1 to 4 are placed in different quarters. In the quarter-finals, eight players remain, one from each eighth, so seeds 1 to 8 occupy different eighths. Extending this to a 16-slot bracket gives 1, 16, 8, 9, 4, 13, 5, 12, 2, 15, 7, 10, 3, 14, 6, 11.
The consequence is that the sum of the two seed numbers in every first-round match is the same: bracket size plus one. In an 8-slot bracket every pair adds to 9, and in a 16-slot bracket every pair adds to 17. That is the signature of a correctly seeded draw, and it is also the quickest way to check one. If you see 1 playing 4 in the first round, the bracket was not seeded.
The recursion also explains why the shape is not symmetric in the way people expect. Seed 1 sits at the top of the upper half and seed 2 at the top of the lower half, but seeds 3 and 4 are not next to them; they are in the middle of the draw, in the quarters that meet the top two only in the semi-finals. Drawing a bracket by hand tends to put the best four players in the four corners, which is a different and less fair arrangement.
Byes, match counts and why the numbers always agree
A bracket with S slots has exactly S − 1 matches, whatever the number of byes. That identity is a useful check on any generated schedule.
Every match eliminates one player, and a single-elimination tournament with S slots ends with one winner, so it must eliminate S − 1 players. The identity holds regardless of how the byes are distributed: an 8-slot bracket has 7 matches, whether it holds 8 players and no byes or 6 players and two byes. With 6 players, two of the seven matches are byes, so five are actually played.
The number of byes is always the bracket size minus the number of players, and it is always less than half the bracket. That follows from the size being the smallest power of two that is at least the player count: if the player count were at or below half the size, the next smaller power of two would have been enough. Because byes are fewer than half the slots, no first round can consist entirely of byes, and the round always produces at least one real match.
Round 2 is where the effect of the byes shows up. Half of the slots advance, and the players who had a bye arrive rested while those who played arrive with a match behind them. That is the intended reward: the top seeds get the easier route. Whether that is fair over a single tournament is a matter of format design, but within the standard seeded bracket it is consistent: the second round deliberately mixes players who have already played with players who have not.
A ten-player knockout needs sixteen slots and six byes
Knockout brackets have to be a power of two in size: ten players take sixteen slots, which leaves six byes. The number of byes is simply slots minus players, and they exist only in the first round.
The size is the smallest power of two at or above the player count: six players take eight slots with two byes, seven take eight with one, eight take eight with none, ten take sixteen with six. The round count is the base-two logarithm of the size, so eight slots is three rounds and sixteen is four.
Byes can only fall in the first round. Allow one later and that round has a winner who did not play, which the schedule cannot represent — so every bye is placed in round one, after which each round has a power of two players.
Another place that cannot be short-cut: apart from byes advancing automatically, every winner is left blank, pending. The known side of a match is not pushed forward just because it is known — that would be announcing a result the match has not produced.
Which is also why this page builds structure and never predicts. The seeding order is produced by splitting halves symmetrically, with seed one and the lowest seed at opposite ends and seeds two and three in different halves, so the top seeds can only meet in the final. Who wins still has to be played.
The bracket never shuffles: the order you type is the seeding
Position in the list is the seed number, and the slot layout is derived from those numbers. Nothing is randomised at any point.
Eight names placed in a list come out as 1 against 8, 4 against 5, 2 against 7 and 3 against 6 in the first round. Seeds 1 and 2 land in opposite halves of the draw, which is why they cannot meet before the final however the rest of the results go.
The consequence is that pasting names alphabetically declares alphabetical seeding. The bracket is then a correct drawing of a wrong premise, and it will look perfectly reasonable while producing a lopsided draw. A real draw settles the order first, by ranking, by qualifying time or by a public lot, and pastes it in that order.
There is also no re-seeding between rounds: a winner keeps the slot they won in, so the entire tree is fixed the moment the first match starts. That is the standard club format, and a re-seeded draw with a fresh shuffle each round is a different object that this tool does not claim to produce.
Frequently asked questions
Why do byes go to the top seeds?
Because the bracket is meant to reward the ranking. A bye is an easier path, and the top seed is supposed to have the easiest path on paper. If a bye went to a low seed, that player would skip a round while the strongest player did not, which inverts the whole point of seeding. The same rule also keeps the byes concentrated at the top of the draw, which is where the seeding says the easier paths belong.
Why does six players need an eight-slot bracket?
Because the first round has to pair players off completely. With six players you could play three matches and have three winners, which is not a power of two and cannot be halved again into a clean bracket. Rounding up to eight gives four first-round matches, two of which are byes, and then four players remain for the semi-finals. The alternative, a play-in round, is a different format and produces a different schedule.
What happens with an odd number of players?
Nothing special: the bracket is rounded up to the next power of two and the difference becomes byes. Seven players fit into eight slots with one bye, which goes to seed 1. The number of byes is always the bracket size minus the player count, and it is always smaller than half the bracket, so there is never a round where everyone sits out.
Can I change the draw after it is generated?
Change the list order. The first name is seed 1, so reordering the list reorders the seeds, and the bracket is rebuilt from scratch. There is no separate reseeding step, because reseeding mid-tournament is a different format with its own rules. If you want a random draw instead of a seeded one, shuffle the list before pasting it in.
Does the bracket predict who wins?
No. Apart from byes, which are not matches at all, every slot after the first round is left open. A bracket is a statement about who can meet and in which round; filling in winners would turn it into a forecast, and this tool does not make forecasts. It also does not handle double elimination, groups, or third-place play-offs.
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