No description, website, or topics provided.
Switch branches/tags
Nothing to show
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Failed to load latest commit information.


During the 2017 NCAA football season, David Burge proposed a simple, easy-to-comprehend system for determining which NCAA football teams would be invited to the four-team playoff - the "marble game." The rules of the game are simple:

  • Each team starts with a pre-determined amount of marbles.
  • If a team wins a home game, they take 20% of the loser's marbles.
  • If a team wins a road game, they take 25% of the loser's marbles.
  • Neutral site games are treated as home wins for the victor (20% marble transfer).

The motivation behind the #marblegame is simple:

The point of the #MarbleGame is that CFB playoff selection could be simple, open, & transparent, not backroom committees lobbying for the outcome of a beauty contest.

— David Burge (@iowahawkblog) December 3, 2017

Package features

The marblr package allows R users to simulate the marble game for NCAA football seasons from 1995 to 2017 (data scraped from Massey Ratings). The marble_game function takes four inputs:

  • ncaa_games: A dataframe that comes with the marblr package with game result data scraped from Massey Ratings.
  • yr: A four-digit year from 1995 to 2017, indicating the desired football season.
  • wk: A integer to determine the maximum week of the season to include. By default, it will pull all available weeks. If you want to limit to the first 6 weeks of the season, you would set this parameter to 6.
  • p5_value: An integer to determine the initial marble count given to teams from the 2017 Power 5 conferences (ACC, Big 10, Big 12, Pac 12, SEC, and Notre Dame) at the start of a season. This defaults to 120 for teams from the Power 5 and 100 for all other schools.