Tournament bracket maker for knockouts and leagues

Pick the format first

Common tournament formats and what they need
Format	How it works	Good for	What the app must handle
Single elimination	Lose once and you're out	Many entrants, little time	Seeding, byes, third-place match
Double elimination	Out after two losses, with a losers' bracket	Games where one bad round shouldn't end the day	Two brackets that feed each other, a possible reset final
Round robin	Everyone plays everyone	Small groups, leagues, fairness	Fixture list, league table, tie-breaks
Groups then knockouts	Round-robin groups, top finishers into a bracket	Sports days, esports nights	Both of the above, and who goes through

Byes and seeding, done properly

A knockout bracket works cleanly with 4, 8, 16 or 32 entrants. With any other number, some entrants get a bye into the second round. For 11 entrants in a 16-slot bracket, 16 minus 11 gives 5 byes: 6 entrants play three first-round matches and 5 go straight through. The byes should go to the top seeds, and seeds should be placed so the top two can only meet in the final.

Ask the model for standard seeding (1 plays the lowest seed, 2 is placed in the opposite half), a choice between seeded and random draws, and a check that no first-round match has two byes. Then test it with 5, 11 and 13 entrants, where bracket generators most often go wrong.

Round robins and league tables

A round-robin generator should produce a balanced schedule: with an even number of teams, everyone plays once per round; with an odd number, one team sits out each round in turn. The usual method (the circle method) rotates everyone around one fixed team.

The league table needs the points rule (for example 3 for a win, 1 for a draw) and, crucially, an agreed tie-break order: points, then head-to-head, then goal or point difference, then points scored. Put the order on screen, so the argument happens before the final game rather than after it.

Running it on the day

Result entry. Tap a match, enter the score, and the winner advances or the table updates. Allow corrections; someone always enters a score backwards.
Display view. A large, read-only bracket for a projector or TV, with the current and next matches highlighted.
Print view. A clean, black-on-white bracket for the wall. Ask for it and test with your browser's print command, landscape.
Saved as you go. Results are kept in that browser, so a closed tab or flat battery doesn't lose the afternoon.

Describing your tournament

"A tournament bracket maker for our office table tennis day. 14 players, seeded from a list I paste in. Single elimination with byes to the top seeds and a third-place match. Tap a match to enter the score, winners advance. A projector view with the next three matches, and a print view. Bold, sporty, readable from the back of the room." For a league: "Round robin for seven teams, home and away, 3 points for a win, 1 for a draw, tie-break on head-to-head then point difference."

Limits

One device is the scorer. Results entered on the organiser's laptop don't appear on players' phones. Show the display view on a screen everyone can see.
No live public bracket. People following from home can't load live results; there's no shared data or network in the sandbox.
No registration or entry fees inside the app. Collect entries beforehand with a form; in an app, a contact or enquiry form sends each entry to you by email. Fees go through a payment link from your own provider.
Esports integrations. It can't pull results from a game or a platform.

For a single game's score, the scoreboard app is simpler, and a whole event with a schedule and sign-ups belongs on a tournament website.

Questions people ask

Can the tournament bracket maker handle an odd number of teams?

Yes. Knockouts use byes for the top seeds, and round robins give one team a rest each round.

Can players see the bracket on their own phones?

Not live. Results stay on the device used to enter them, so share a screen or a printed sheet.

Can I keep a season's league?

Results are saved in that browser across visits. Ask for an export file as a backup.