bracket-creator

A CLI to create kendo tournament brackets

Web UI

Start the web server and open your browser at http://localhost:8080:

bracket-creator serve

With Docker:

docker run -p 8080:8080 ghcr.io/gitrgoliveira/bracket-creator/bracket-creator:latest

or with docker-compose:

docker-compose up -d

Quickstart Demo

The images below show the full workflow: entering participants, seeding past winners, and generating the bracket file.

Using the Form

About Dojo: In pool tournaments, the Dojo field is used to ensure participants from the same dojo are not placed in the same pool.

Seeding Participants (Web UI)

Click the ☆ Seed Participants button to open the seeding modal. This lets you lock past tournament winners into advantageous bracket positions before the draw.

In the modal:

• Each participant is listed with their dojo and a Seed Rank input field.
• Enter a positive integer to seed a participant (e.g., 1 = top seed, 2 = second seed).
• Leave a field empty to place the participant in the unseeded pool.
• Seed ranks must be unique — duplicate ranks will be rejected with an error.
• Seeded participants are strictly validated: every seeded name must exactly match a name in the participant list (case-sensitive). If a name does not match, the bracket generation will fail with a clear error.

After saving, the button label changes to ★ N Seeds Assigned (highlighted in amber) and the seeds are submitted with the form.

There's also a CLI. To learn how to use the CLI run:

bracket-creator --help
bracket-creator create-pools --help
bracket-creator create-playoffs --help

Example to build the tool from source:

make go/build

Input file format

The input file can be a simple list of names or a CSV formatted file. For example:

First_Name Last_Name, Dojo

For teams, it should be just one team per line.

When using the CSV formatted style, Dojo is only used to try to ensure players/teams don't meet someone of the same dojo when doing pools.

Customizing the web server

To set the listen address and port run:

bracket-creator serve --listen-address 0.0.0.0 --listen-port 8080

You can also use the environment variables:

export BIND_ADDRESS=0.0.0.0
export PORT=8080

CLI Parameters to create Pools

Example command line to create pools with 5 players and 3 winners per pool:

bracket-creator create-pools -z -p 5 -w 3 -f ./mock_data_medium.csv -o ./pools-example.xlsx

• -d / -determined - Do not shuffle the names read from the input file
• -f / -file - Path to the CSV file containing the players/teams in Name, Dojo format. Dojo is a field to ensure players/teams don't endup fighting someone of the same dojo
• -h / -help - Show help
• -o / -output - Path to write the output excel file
• -p / -players - Minimum number of players/teams per pool. Extra players are added to existing pools if there are more than expected. The default is 3. Mutually exclusive with --max-players.
• -m / -max-players - Maximum number of players/teams per pool. Extra pools are created so no pool exceeds this size. Mutually exclusive with --players.
• -w / -pool-winners - Number of players/teams that can qualify from each pool. The default is 2
• -r / -round-robin - Round robin, to ensure that in a pool of 4 or more, everyone would fight everyone. Otherwise, everyone fights only twice in their pool. The default is False
• -z / -with-zekken-name - Use the second column of the input CSV as the participant's display name on the zekken. If empty, falls back to a sanitized name.
• -t / -team-matches - Create team matches with x players per team. Default is 0, which means these are not team matches
• -c / --courts - Number of Shiaijo (courts) to distribute pools across. Must be between 1 and 26. Pools are split evenly and the Pool Matches sheet gains one labelled column per court ("Shiaijo A", "Shiaijo B", …). Each tree sheet is labelled with the matching Shiaijo name. Default is 2.
• --mirror - Mirror match sides (White on left, Red on right). Default is true. To disable, use --mirror=false.
• -n / --number-prefix - Assign consecutive numbers with this letter prefix (e.g. K produces K1, K2, …)
• --title-prefix - Title prefix for the tournament (default "")
• --single-tree - Create a single tree instead of dividing into multiple sheets

CLI Parameters to create Playoffs

Example command line to create team playoffs with 5 players per team:

bracket-creator create-playoffs -t 5 -f ./mock_data_small.csv -o ./playoffs-example.xlsx

• -d / -determined - Do not shuffle the names read from the input file
• -f / -file - Path to the CSV file containing the players/teams in Name, Dojo format. Dojo is a field to ensure players/teams don't endup fighting someone of the same dojo
• -h / -help - Show help
• -o / -output - Path to write the output excel file
• -z / -with-zekken-name - Use the second column of the input CSV as the participant's display name on the zekken. If empty, falls back to a sanitized name.
• -t / -team-matches - Create team matches with x players per team. Default is 0, which means these are not team matches
• -c / --courts - Number of Shiaijo (courts). Must be between 1 and 26. Each tree sheet is labelled with the matching Shiaijo name ("Shiaijo A", "Shiaijo B", …). Default is 2.
• --mirror - Mirror match sides (White on left, Red on right). Default is true. To disable, use --mirror=false.
• -n / --number-prefix - Assign consecutive numbers with this letter prefix (e.g. K produces K1, K2, …)
• --seeds - Path to a CSV file mapping exact participant names to their initial seed rank (see Seeding via CLI)
• --title-prefix - Title prefix for the tournament (default "")
• --single-tree - Create a single tree instead of dividing into multiple sheets

Seeding via CLI

Seeding assigns past tournament winners to favourable positions in the bracket so they don't meet each other in the early rounds.

Prepare a seeds CSV file with the following format (header required):

Rank,Name
1,Alice Dupont
2,Bob Martinez
3,Charlie Chen

Then pass it to the command with --seeds:

bracket-creator create-playoffs -f ./players.csv -o ./playoffs.xlsx --seeds ./winners.csv

Important rules:

• Names must match exactly (case-sensitive) to a name in the main participant list.
• A name that cannot be matched will cause the command to fail with a descriptive error.
• Seed ranks must be unique — duplicate ranks are rejected.
• Seeded participants are placed first in the bracket, following standard bracket distribution (e.g., seeds 1 and 2 placed on opposite halves). Unseeded participants fill the remaining slots.

Examples

See also the example files created by the Makefile:

• playoffs-example-small.xlsx
• playoffs-example-medium.xlsx
• playoffs-example-medium-seeded.xlsx
• playoffs-example-large.xlsx
• playoffs-example-large-seeded.xlsx
• pools-example-small.xlsx
• pools-example-medium.xlsx
• pools-example-medium-seeded.xlsx
• pools-example-large-teams.xlsx
• pools-example-large-teams-max-size.xlsx
• pools-example-large-max-size.xlsx
• pools-example-large-seeded.xlsx

Individual pool player tournament

With 4 players and 2 winners per pool with sanitized names:

./bin/bracket-creator create-pools -z -p 4 -f mock_data.csv -o output.xlsx

Team pool tournament

With 5 players per team:

./bin/bracket-creator create-pools -t 5 -f mock_data.csv -o output.xlsx 

Individual playoffs player tournament

Straight knockout with sanitized names:

./bin/bracket-creator create-playoffs -z -f mock_data.csv -o output.xlsx

Team pool tournament

Straight knockout team competition with teams of 3:

./bin/bracket-creator create-playoffs -t 3 -f mock_data.csv -o output.xlsx

How to Use the output files

Generated workbooks are built from code (see internal/excel/template.go). To customise styling, edit the final output file directly.

To be able to print the tree, you will need to reset the width and height in the Page Layout tab.

On the day of the tournament

These files are generated to be uploaded to Google Drive (or similar), so all shiai-jo tables are in sync during the tournament, working from the same file.

Install - WIP

Please use the pre-compiled binaries from the release page or build from sratch with make go/build The instructions below do not work yet.

You can install the pre-compiled binary (in several ways), use Docker or compile from source (when on OSS).

Below you can find the steps for each of them.

brew install gitrgoliveira/tap/bracket-creator

echo 'deb [trusted=yes] https://apt.fury.io/gitrgoliveira/ /' | sudo tee /etc/apt/sources.list.d/gitrgoliveira.list
sudo apt update
sudo apt install bracket-creator

echo '[gitrgoliveira]
name=Gemfury gitrgoliveira repository
baseurl=https://yum.fury.io/gitrgoliveira/
enabled=1
gpgcheck=0' | sudo tee /etc/yum.repos.d/gitrgoliveira.repo
sudo yum install goreleaser

go install github.com/gitrgoliveira/bracket-creator@latest

$ VERSION=v1.0.0
$ OS=Linux
$ ARCH=x86_64
$ TAR_FILE=bracket-creator_${OS}_${ARCH}.tar.gz
$ wget https://github.com/gitrgoliveira/bracket-creator/releases/download/${VERSION}/${TAR_FILE}
$ sudo tar xvf ${TAR_FILE} bracket-creator -C /usr/local/bin
$ rm -f ${TAR_FILE}

$ git clone github.com/gitrgoliveira/bracket-creator
$ cd bracket-creator
$ go generate ./...
$ go install

Contribute to this repository

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