With n players there are n − 1 matches, and empty slots become byes
In a single-elimination tournament every match knocks out exactly one player (or team), and play continues until one champion is left. With n players the number of matches is therefore always n − 1. The bracket needs a number of slots that is a power of two (2, 4, 8, 16, 32, 64) so that each round cuts the field exactly in half. With 12 players you use a 16-slot bracket, and the 4 unused slots become byes: first-round spots with no opponent. That 12-player bracket runs 4 rounds and 11 matches.
This tool builds brackets for 2 to 64 participants using a random draw, seeding or your list order. You record a score and a winner for each match and the next round fills in by itself. Wide screens show a bracket that converges from both sides into the final in the middle; narrow screens show one that flows from left to right. You can add a third-place match and share the result as text, PNG, print or a link.
When it helps to build the bracket yourself
- Office and school sports days: with 8 to 16 teams, drawing the lines on paper takes longer than the matches themselves. Paste the roster, get the bracket, and print it on US Letter landscape for the notice board.
- Club tournaments: in sports with clear skill gaps, such as table tennis, badminton or bowling, seeding keeps the strongest players from meeting in round one. List players from strongest to weakest and choose "By seed".
- Gaming and esports nights: among friends or a club, the draw has to look fair or people grumble afterwards. The random draw shuffles with the browser's cryptographic random numbers, and everyone can watch the names land in their slots.
- Running the day: on the match board, enter a score or click the winner, and the next round fills in and the next match is shown. Send the result text or a link to the group chat.
How to use it
- Type one participant (or team) per line. You can paste a spreadsheet column, or a single line separated by commas, and it is split for you. Under the list you immediately see how many slots the bracket has, plus byes and matches.
- Choose a placement. Random draw shuffles the list, By seed treats the first line as seed 1, and List order fills the slots in the order you typed. If you like, add a tournament name and switch on the third-place match.
- Press "Make bracket" and the names are placed into the first-round slots one by one. With a random draw you can press "Redraw" to shuffle again.
- When a match ends, click the winner's name on the match board or enter the two scores. With different scores the higher one wins, and the board moves on to the next match. Clicking a name in the bracket itself also records it as the winner.
- When the final is done, the champion box and the summary strip show the champion, runner-up and third place. Share the result with Copy text, Save PNG, Print / PDF or Copy link.
The dots on the right of the summary strip stand for the matches in each round. Finished matches are filled, the selected match has a highlighted outline, and small dotted dots are bye slots. Hover over a name in the bracket, or focus it with the keyboard, and the boxes and lines that player has passed through get darker so you can see the path they took. Once a champion is decided, that whole path stays as a thick line.
Matches, rounds and byes
Bracket slots = the smallest power of two that is at least n (2, 4, 8, 16, 32, 64)
Byes = slots − n
Rounds = log₂(slots)
Matches = n − 1 (n with a third-place match)
Real first-round matches = n − slots ÷ 2
Byes only occur in the first round. Even when the slot count is larger than n, n is more than half the slot count, so every first-round match has at least one player in it. From the second round on, every match has two players. The table below is copied straight from the calculation this tool uses.
| Players | Slots | Byes | Rounds | First-round matches | Total matches | With third-place match |
|---|---|---|---|---|---|---|
| 3 players | 4 | 1 | 2 | 1 | 2 | None |
| 4 players | 4 | 0 | 2 | 2 | 3 | 4 |
| 5 players | 8 | 3 | 3 | 1 | 4 | 5 |
| 6 players | 8 | 2 | 3 | 2 | 5 | 6 |
| 8 players | 8 | 0 | 3 | 4 | 7 | 8 |
| 10 players | 16 | 6 | 4 | 2 | 9 | 10 |
| 12 players | 16 | 4 | 4 | 4 | 11 | 12 |
| 16 players | 16 | 0 | 4 | 8 | 15 | 16 |
| 20 players | 32 | 12 | 5 | 4 | 19 | 20 |
| 24 players | 32 | 8 | 5 | 8 | 23 | 24 |
| 32 players | 32 | 0 | 5 | 16 | 31 | 32 |
| 48 players | 64 | 16 | 6 | 16 | 47 | 48 |
| 64 players | 64 | 0 | 6 | 32 | 63 | 64 |
One more player than the slot count makes the bracket double in size and adds a round. 16 players finish in 4 rounds, but 17 players need a 32-slot bracket, 5 rounds and 15 byes. When planning the day, the number of rounds can matter more than the number of matches: matches in the same round can run at the same time if you have several courts, but a round cannot start until the previous one is finished.
Seeding: seeds 1 and 2 only meet in the final
A seed is a ranking number used to place stronger players so that they do not meet early. For a bracket with S slots, this tool's "By seed" spreads each seed s into the pair (s, S + 1 − s). So the first round is always something like "seed 1 against the lowest seed", and if there are no upsets the semifinals are seed 1 against seed 4 and seed 2 against seed 3, followed by seed 1 against seed 2 in the final.
| Bracket slots | First-round pairs |
|---|---|
| 4 slots | 1 vs 4 · 2 vs 3 |
| 8 slots | 1 vs 8 · 4 vs 5 · 2 vs 7 · 3 vs 6 |
| 16 slots | 1 vs 16 · 8 vs 9 · 4 vs 13 · 5 vs 12 · 2 vs 15 · 7 vs 10 · 3 vs 14 · 6 vs 11 |
When there are fewer players than slots, the empty slots are the ones whose seed number is greater than the number of players. That is why with seeding the byes go to the top seeds first. With 6 players, slots 7 and 8 are empty, so seeds 1 and 2 skip the first match and go straight to the semifinals. The 2025 rules of the men's professional tennis tour (ATP) likewise place seed 1 on the first line of the draw and seed 2 on the last, and in a 28-player main draw they give byes to the top 4 seeds.
How this differs from tennis rules The ATP rules fix only seeds 1 and 2; seeds 3 and 4 and the rest are drawn into set groups of positions. This tool skips the draw and fixes every seed to the position in the table above, so the same roster always gives the same bracket. It does not replace the draw rules of an official competition.
Random draw, By seed and List order compared
| Placement | How slots are assigned | Who gets the byes | First round with 6 players |
|---|---|---|---|
| Random draw | The list is shuffled, then placed into the seed positions | Decided by the draw | Different every time |
| By seed | First line is seed 1, positions as in the table above | Top seeds first | A bye · D vs E · B bye · C vs F |
| List order | Slots without a bye are filled from the top in list order | The lines that land in bye slots | A bye · B vs C · D bye · E vs F |
Use List order when you want to carry over a bracket you have already decided. If the number of players equals the slot count, entries 1 and 2 meet, then 3 and 4, and so on. When there are byes, the bye slots are spread evenly across the top and bottom of the bracket, so the pairs shift by a line, as in the example above. If you want particular pairs, make the bracket, look at the first round, change the list order and make it again.
Adding a third-place match
A third-place match is a game between the two teams that lost their semifinals, to decide third place. The regulations of the 2026 FIFA World Cup also provide for a match for third place between the two semifinal losers. Switching it on raises the number of matches from n − 1 to n, and its match number comes right before the final, so that the final is the last match of the tournament.
With the third-place match off, the two semifinal losers are shown as joint 3rd. If you have one prize for third place or need exactly one person for the group photo, leave it on. With 3 players one semifinal is a bye, so there is only one loser and the third-place match cannot be switched on.
Rules for recording results
- With different scores, the higher score wins. Fill in both score boxes, then leave the box or press Enter to record it. Scores are whole numbers from 0 to 999.
- With a tie, click the name of whoever won by a shootout, extra time, a draw of lots or another rule you set. The score stays as a tie and only the winner mark is added.
- You can also click the lower-scoring side as the winner, for example when the opponent withdrew or was disqualified. The board marks this separately as a win with the lower score.
- If you change an earlier result, the player who moved on changes, so the results of later matches that player was in are cleared. You are told how many were cleared, and "Undo" brings them straight back. If you only correct a score and the winner stays the same, the later results are kept.
- For a typo in a name, keep the line order, fix only that line and press "Apply name edits". Positions and results stay, and only the name changes. If you move lines or change the number of players, you need to make a new bracket.
How fair is the random draw?
The random draw shuffles the list with random numbers from the browser's crypto.getRandomValues(). MDN describes this function as providing cryptographically strong random values. The shuffle is the random-permutation algorithm Durstenfeld published in 1964 (the Fisher–Yates shuffle). To avoid the bias that appears when you take a remainder by the number of slots left at each step, out-of-range random values are discarded and drawn again. As a result every arrangement is equally likely.
There are more possible brackets than you might expect. Placing 8 players in 8 slots can be done in 40,320 ways, but swapping the two players in a match or flipping a top and bottom half gives the same bracket, so there are only 315 different brackets. With 16 players there are 638,512,875. Once the bracket is set, each match can go two ways, so the number of possible outcomes is 2 to the power n − 1. The NCAA puts the odds of picking every result of a 64-team, 63-match tournament at about 1 in 9,223,372,036,854,775,808 (roughly 9.2 quintillion).
| Players | Different brackets (n! ÷ 2n−1) | Possible outcomes (2n−1) |
|---|---|---|
| 4 players | 3 | 8 |
| 8 players | 315 | 128 |
| 16 players | 638,512,875 | 32,768 |
| 64 players | about 1.4 × 1070 | 9,223,372,036,854,775,808 |
A fair draw is worthless if the way it is run is not fair. If you keep pressing "Redraw" until you get a bracket you like, you have in effect chosen it. Press it once in front of the participants, and save the screen as a PNG or send the link right away, so nobody can suspect you changed it later.
Sharing, printing and saving
- Copy text: copies each round's match numbers, pairings, scores and winners, the list of byes and the champion as plain text, ready to paste into a group chat.
- Save PNG: saves the whole bracket as an image together with the tournament name. It always uses the poster layout that converges from both sides, whatever your screen width.
- Print / PDF: prints the same image to fit one US Letter landscape page. The site menu and ads are not printed. Choose "Save as PDF" in the print dialog to get a PDF.
- Copy link: makes a link that carries the roster, positions, scores and winners after the # in the address. Whoever opens it sees the same bracket and results. What comes after the # is read only inside the browser and is never sent to the site's server.
- Continue in this browser: when you make a bracket or change a result, it is saved automatically in this browser and comes back the next time you open the page. To continue on another device, send the link and open it there.
Common mistakes
- Counting bye slots as matches: a 5-player bracket has 8 slots, but only 4 real matches. The 3 empty slots are not matches, so leave them out of match times and referee assignments.
- Assuming entries 1 and 2 always meet in List order: when there are byes, the bye slots come in between and the pairs shift. Check the first round, as in the 6-player example in the comparison table.
- Entering the same name twice: with duplicate names you could not tell who won, so no bracket is made. Add a group or number, such as "Sam (Team B)". Names that differ only in upper and lower case are treated as the same name.
- Splitting a doubles pair into two lines: for 6 doubles teams, enter one team per line, such as "Ana & Ben", for 6 lines. Entering 12 lines makes a 12-player singles bracket.
- Changing the roster during the event: adding or removing players changes the bracket size and positions, so results are not kept. If someone withdraws, do not delete them from the list; record their opponent as the winner.
Limits
- It only makes single-elimination brackets, where one loss knocks you out. Double elimination, round-robin leagues where everyone plays everyone once (n(n − 1) ÷ 2 matches for n players), Swiss systems and group stages followed by knockouts are not supported.
- One bracket holds up to 64 players (teams), and names can be up to 30 characters.
- Seeding uses a single ranking number. There is no option to keep players from the same club apart in the first round, so if you need that, place them yourself with List order.
- The link and this browser's saved results are not live shared editing. If several people record results separately, each link ends up with different results. Let one person keep the record and send a new link or text whenever it changes.
- Results saved in this browser disappear if you clear site data or close a private window. Keep a PNG or a link of any bracket you want to keep.
Sources
As of The ATP rules, FIFA regulations, NCAA odds and MDN description were checked against the originals on 24 October 2026. The tables of matches, seed positions and counts were recounted with this tool's calculation on the same day.
- 01ATP — 2025 Official Rulebook, Chapter 7 The Competition7.16 main draw seeding (seed 1 on the first line, seed 2 on the last, seeds 3 and 4 drawn), 7.18 byes (top 4 seeds in a 28-player draw, all seeds in 48 and 96-player draws)
- 02FIFA — Regulations FIFA World Cup 2612.1 stages of the competition (semi-finals, match for third place, final), 12.10 match for third place between the two semi-final losers
- 03NCAA.com — The absurd odds of a perfect NCAA bracketOdds of a perfect bracket: about 1 in 9,223,372,036,854,775,808
- 04Richard Durstenfeld — Algorithm 235: Random permutationCommunications of the ACM 7(7), 1964, p. 420. The shuffle this tool uses
- 05MDN — Crypto: getRandomValues() methodThe browser feature that provides cryptographically strong random values
Frequently asked questions
How is the bracket built when the number of players is not a power of two?
It uses the smallest power-of-two bracket that fits all players (4, 8, 16, 32 or 64 slots) and leaves the extra slots as byes. For example, 12 players get a 16-slot bracket with 4 byes, and anyone with a bye moves to the next round without playing a first-round match.
Who gets the byes?
With seeding, the top seeds get them starting from seed 1. With a random draw, who gets a bye is drawn too. With list order, the lines that land in the bye slots, spread evenly across the top and bottom of the bracket, get them. Byes only occur in the first round.
How many matches are played in total?
In single elimination every match knocks out one player, so n players mean n − 1 matches. Byes are not counted as matches. Turning on the third-place match adds one, making it n matches.
Is the random draw fair?
It shuffles with the browser's cryptographic random numbers (crypto.getRandomValues) using a Fisher–Yates shuffle, so every arrangement is equally likely. Redrawing until you get the bracket you want is not fair, though, so press it once in front of the participants and save or share the result right away.
How do I record the winner when the scores are tied?
Enter the tied scores, then click the name of the side that won by a shootout, extra time, a draw of lots or similar. The scores stay as they are and only the winner mark is added. You can also click the name when the lower-scoring side wins, for example after a withdrawal or disqualification.
What happens if I change a result I already recorded?
If the winner changes, the results of the later matches that winner had reached are cleared, and you are told how many. Pressing Undo takes you straight back. If you only correct a score and the winner stays the same, the later results are kept.
How do I send the bracket to someone else?
Copy link makes a link that carries the roster, positions, scores and winners after the # in the address, so the recipient sees the same bracket and results. Use Save PNG for an image, Copy text for plain text, or print it ad-free on US Letter landscape for paper.
Can it make round-robin leagues or double elimination?
No. This tool only makes single-elimination brackets, where one loss knocks you out. A round-robin league where everyone plays everyone once takes n(n − 1) ÷ 2 matches; with 6 teams that is 15 matches, three times the 5 matches of a single-elimination bracket.