For the 2016-17 school year, CHASAA has moved to a new ranking formula called the Rating Percentage Index (RPI). This is the formula being used to rank varsity team sports for playoffs. It is used by NCAA and considers not only a team’s record, but the strength of the teams played.
This formula will be used for all team sports across Colorado including Baseball, Basketball, Football, Hockey, Lacrosse, Soccer, Softball, and Volleyball. It does not apply to sports dominated by individual performance such as Gymnastics, Tennis, Track & Field, etc.
Here is an article found on the CHSAANow website that explains the system.