How to create a free Go tournament (McMahon system)

Want to run a Go (Baduk / Weiqi) tournament without wrestling with spreadsheets? This tool lets you create a Go tournament for free, with automatic McMahon pairing, live standings and player management by rank. Nothing to install.

Why the McMahon system is ideal for Go

The classic Swiss system makes strong and weak players wait several rounds before they meet opponents at their level. The McMahon system fixes this: every player starts with an initial score based on their rank (kyu/dan), so from round one they face players of similar strength. It is the standard format at nearly every Go tournament in the world.

• Initial score by rank: dan players start higher and kyu players lower, split into bands.
• Balanced games from round 1: fewer walkovers and fewer blowouts.
• Works with many players and few rounds: ideal for one-day tournaments.

How to create a Go tournament step by step

1. Create a free account. Sign up in under a minute; no card required.
2. Create a competition and choose the McMahon format. Give it a name, dates and number of rounds.
3. Add players with their rank. Enter the level (for example 5k, 1d, 3d) to compute the initial score.
4. Set up the bands and seeding. Order the list; the system places each player in their McMahon band.
5. Generate pairings and share the standings. Publish results round by round with standings that update on their own.

A worked example: a club tournament with very different levels

Picture a club tournament with 40 players ranging from 15 kyu to 3 dan. Under the McMahon system, players are split into bands: for instance, everyone rated 1 dan or higher joins the top band with a 20-point initial bonus, players between 5 kyu and 1 kyu get 10 points, and players from 15 kyu to 6 kyu start at 0. This way, a 3 dan and a 1 dan can already meet in round 1 without a nonsensical result, while a 15 kyu takes a few rounds to climb toward the mid-level players. With this initial bonus, a 5- or 6-round tournament is usually enough for a reliable final ranking — under a pure Swiss system starting everyone at 0, it would take considerably more rounds for the pairings to "discover" on their own who is strong and who isn't.

Tips for pairing well with McMahon

• Define the bands before the tournament starts: decide how many bonus points separate each rank bracket (for example, one point per rank difference) and publish it so players understand the scoring.
• Set a floor (the "McMahon bar"): weak players shouldn't be dragged into a negative score; set a minimum so they keep competing with real chances.
• Record each player's actual rank, not one they recall from memory: use their federation rank or the one from their last event if available, so the initial bonus is fair.
• Decide the game-scoring rules in advance: Japanese rules (territory + prisoners) or Chinese rules (area); it doesn't change the pairing, but it avoids arguments on tournament day.

Common mistakes when running a McMahon tournament

• Mixing very different ranks without a handicap adjustment: pitting an 18 kyu against a 4 dan with no handicap stones leaves a completely lopsided game, even if the McMahon pairing is correct on paper.
• Running too few rounds for a very wide range of levels: when the gap between the weakest and the strongest player is large, three rounds fall short: the initial bonus never gets fully balanced against actual playing strength.
• Not setting a score floor: without a minimum (the McMahon bar), a player on a losing streak ends up with a negative score that removes them from any competitive game for the rest of the tournament.
• Forgetting to update rank before the tournament: a player who has climbed several levels since their last event can end up misplaced in a lower band, distorting the pairings of their opponents too.

McMahon vs. the classic Swiss system

The key difference is the starting point. The pure Swiss system (the one used in chess) starts every player at 0 points and only takes into account what happens inside the tournament itself; it needs quite a few rounds before the pairings truly reflect each player's level. The McMahon system starts from a fact that is already known beforehand — each player's kyu/dan rank — and turns it into an initial bonus. This makes it ideal for Go clubs, where there is usually a wide, well-known gap in level among participants: within a few rounds, the standings already separate strong players from weaker ones, something a pure Swiss system would need far more rounds than a one-day tournament allows.

Frequently asked questions

Is it really free to create a Go tournament?

Yes. You can create and manage your Go tournament for free, including McMahon pairing, rank bands and live standings.

What is the McMahon system and how does it differ from pure Swiss?

It is a variant of the Swiss system where each player starts with an initial score (the "McMahon number") based on their rank, instead of everyone starting at 0. This keeps pairings balanced from round one, which matters when the field mixes very different levels.

How is each player's initial score calculated?

Ranks are grouped into bands (for example, dan players at the top, mid kyu in the middle, low kyu at the bottom), and each band gets a different bonus. The higher the rank, the bigger the initial bonus relative to the band below it.

What is the difference between kyu and dan for the tournament?

Kyu is the beginner-to-intermediate level and counts downward (20 kyu is weaker than 5 kyu); dan is the advanced level and counts upward from 1 dan. Both ranks are used to set each player's band and initial bonus.

Do I need handicap stones in the tournament games?

It is common in clubs with large rank gaps: handicap stones compensate for the level difference between opponents so the game stays competitive, independently of the score adjustment the McMahon system already makes in the standings.

How many rounds are needed for a reliable ranking?

Thanks to the initial rank bonus, a McMahon tournament usually needs quite a few fewer rounds than a pure Swiss to reach a reliable ranking; 5-6 rounds are usually enough for a medium-sized field.

Does the tool score each game (territory or area)?

No; game scoring (by territory and prisoners under Japanese rules, or by area under Chinese rules) is decided by the club and played out on the board. The tool handles McMahon pairing, bands and the tournament standings, not the score of each individual game.

Can I use this same system for a game other than Go?

The McMahon format is specific to Go, but the tool also offers league, cup, knockout, Swiss and americano formats, which do work for chess, padel or other sports and games.

Can I upload the results to the EGD (European Go Database)?

Yes. The tool exports the wallist in the official EGD format: fill in each player's rank, country and club and download a file ready to upload to EGD Admin.

What happens if there's an odd number of players, or someone withdraws mid-tournament?

With an odd number of players, the tool automatically assigns the bye with its corresponding win — no action needed. And if a player withdraws, you mark them as withdrawn from an organizer page: they stop being paired in future rounds, but keep their points and already-played games in the standings.

Does the tool assign who plays black and who plays white?

Yes. In McMahon and Swiss pairings, color is assigned automatically, aiming for each player to end the tournament with a similar number of games with each color and avoiding repeating it too many times in a row. It's our own balancing heuristic, not any federation's official color-assignment rules — for tournaments that require very strict color control, review it before publishing the pairing.

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