Directed graphs, PageRank, and College Football

Google’s famous PageRank algorithm works by visualizing the World Wide Web as a directed graph and then solving an associated eigenvalue problem. The same technique can be used to rank teams in a competitive sports league. I did so for this past season’s Big Ten college football season here:

Here are a couple of nice things about this:

  • The directed graph representation is a bit of a mess but you can focus on parts of the graph by hovering over nodes or edges.
  • Numerical analysis is not traditionally a strong suit for Javascript but it’s pretty easy to solve this particular eigenvalue problem using the power method.