How is the RPI different from the Sagarin ratings?
There are two main differences between the RPI and Sagarin’s ratings: • The RPI only cares whether or not a team wins, whereas Sagarin takes into account other things like the margin of victory, etc. • Sagarin’s ratings also have a starting point, based on the previous few years. That starting point is no longer included by the end of the year, however, so that each year can stand on its own. The RPI starts everyone from scratch. That’s why it’s not terribly informative until around midseason. Also, Sagarin doesn’t really release any information about his formula, since he invented it and sells the results, while the basic formula for the RPI is available to anyone who has a computer and too much time on their hands.
