How the bracket is built
A knockout bracket needs a power of two: 2, 4, 8, 16, 32 and so on. With 12 entrants the bracket is 16 wide, so there are 4 byes in the first round. The byes go to the top seeds, which is the usual reward for being seeded high, and each seed's place follows the standard order so the strongest meet as late as possible.
| Bracket size | Round one |
|---|---|
| 4 | 1 v 4, 2 v 3 |
| 8 | 1 v 8, 4 v 5, 2 v 7, 3 v 6 |
| 16 | 1 v 16, 8 v 9, 4 v 13, 5 v 12, 2 v 15, 7 v 10, 3 v 14, 6 v 11 |
Read down the list and each pair of matches feeds one match in the next round. In an 8 bracket, the winners of 1 v 8 and 4 v 5 meet in one semifinal, and the winners of 2 v 7 and 3 v 6 in the other.
Single or double elimination
- Single elimination: lose once and you're out. n entrants play n − 1 matches (15 for 16), over ⌈log₂ n⌉ rounds. It's the quickest way to a winner.
- Double elimination: your first loss drops you into the losers' bracket, and a second loss puts you out. The winner of the losers' bracket meets the winners' champion in a grand final. If the losers' side wins it, both have lost once, so a reset match decides it. With a reset that can be up to 2n − 1 matches (31 for 16), about twice as long as single elimination.
Double elimination is fairer to someone who has one bad game, and it gives everyone at least two matches. Plan the time for it: the losers' bracket has nearly twice as many rounds as the winners' side.
Seeding: by order or at random
Seed by your own order when you know who's strongest, from a ranking, a rating or last year's results. Draw at random when you don't, or when it's a social event and a fair draw matters more than keeping favourites apart. The random draw here uses your browser's cryptographic random numbers, so nobody can predict it.
Printing it
Use the Print button. The page prints the bracket only, landscape is best for 16 or more, and empty slots show where the next winner goes so you can fill them in by hand on the day.
Running it live on Programmable Talk
A printed bracket works for a small room. For anything bigger, Talk's tournament template runs the same bracket from registration to the final: people or teams enter by registering, you can open check-in before the start, then seed at random, by a rating question on the sign-up form, or in your own order. Results move winners on by themselves, a corrected result updates everything after it, players can report their own scores, and the live bracket is on your event's site. It also runs round robins, Swiss rounds and judged competitions.