An Empirical Study of Least Squares Ratings for USA Ultimate Frisbee

Ultimate frisbee is one of the fastest-growing sports in the world. In the United States, the governing body USA Ultimate uses a custom power rating system to determine bid allocations for various competitive tournaments. However, this rating system has significant flaws and leaves room for improvement. In this paper, we apply the least squares rating system and demonstrate its improvement over the current system both qualitatively and relative to a number of quantitative metrics.