# StartGGElo

StartGGElo is a tool for using [start.gg](https://www.start.gg/)'s video game tournament data to
generate and maintain [Elo ratings](https://wikipedia.org/wiki/Elo_rating_system) for each competitive player.

Once Elo ratings are generated, StartGGElo can be used to generate ranking lists, predict the
probability of a player winning a match, generate seedings for future tournaments, and more.

> **Warning**<br>
> StartGGElo is still under development; currently, it only supports generating player ratings.

## Installation

*For more information, see the [installation page](INSTALL.md).*

Build and install StartGGElo using `cargo`:

``` sh
cargo install --git https://github.com/kiana-S/StartGGElo
```

Alternatively, if you use Nix:

``` sh
nix profile install github:kiana-S/StartGGElo
```

## Configuration

StartGGElo stores its rating databases in its config directory, which is located at:

- Windows: `%APPDATA%\Roaming\ggelo`
- MacOS: `~/Library/Application Support/ggelo`
- Linux: `~/.config/ggelo`

This directory also contains StartGGElo's config file, which defines how it calculates its ratings.
There are few reasons to access this directory directly, but you can if you want to transfer your
data between computers.

## Elo system basics

*For more information on StartGGElo's rating system, see the [details page](DETAILS.md).*

As the name implies, StartGGElo uses the Elo system for its ratings. In the Elo system, all newcomers to the
game are assigned an **initial rating**, and this rating is adjusted whenever a player loses or wins matches.
The initial rating for StartGGElo is 1500, but this is configurable.

Whenever a player enters a tournament, StartGGElo will use start.gg's API to determine how many sets
that player won within that tournament. This number is the player's **score** for that tournament. If the score
the player earned is larger than their Elo rating would predict, then their rating is increased.