Introduction Every year I play in several fantasy football (American) leagues. For those who are unaware, it’s a game that occurs every year in sync with the National Football League (NFL) where participants play in weekly head-to-head games as general managers of virtual football teams. (Yes, it’s very silly.) The winner at the end of the season is often not the player with the team that scores the most points; often a fortunate sequence of matchups dictates who comes out on top.
While reading up on modern soccer analytics (I’ve had an itch for soccer and tracking data recently, I stumbled upon an excellent set of tutorials written by Devin Pleuler. In particular, his notebook on non-negative matrix factorization (NNMF) caught my eye. I hadn’t really heard of the concept before, but it turned out to be much less daunting once I realized that it is just another type of matrix decomposition.