Bradley-Terry Model Ranking Script
A small script to compute Bradley–Terry model that:
- Pulls down pairwise match data from a Google spreadsheet.
- Computes the Bradley-Terry model with a simple regularization scheme (dummy games).
- Uploads the scaled scores back to the same Google spreadsheet in a new tab.
I quickly wrote this up in an afternoon so that we could track our relative rankings in ping ping at the office. I put it on a cron job and give everyone access to the sheet at work.
- You will need to setup an API key for gspread to access your Google sheet: http://gspread.readthedocs.io/en/latest/oauth2.html
- Make sure you share the target Google sheet with the email address associated with your credentials (usually a randomly generated one).
- The "Game Data" sheet should have 5 columns:
- The "Ranking" sheet show the score for each player scaled between 0 and 1000. It can be interpreted as probability of Player A beating Player B is (Score_A) / (Score_A + Score_B).