Board of Directors votes to change RPI percentage for all sports

CHSAA seal plaque

(Ryan Casey/

DENVER — The CHSAA Board of Directors voted to tweak the percentage used in the RPI formula for all sports on Wednesday.

It means that the formula will be weighted as follows:

  • 30 percent on a team's own winning percentage
  • 40 percent on the winning percentage of a team's opponents
  • 30 percent on the winning percentage on the opponents of a team's opponents.

This marks a change from the standard 25/50/25 formula, and will be in place for the 2018-19 season. It creates a standard formula across all sports, something that had started to change in recent seasons. Football and baseball currently use formulas that differ from other sports.

Football will continue to use a classification modifier — a 15 percent difference from class-to-class, with one exemption — but no other sport will have a modifier.

The vote came after a recommendation from the Technology Committee, which spent months researching the RPI and gathering feedback from the member schools.

The Technology Committee met several times since last August, including an in-person meeting, and several video conferences, in exploring the future of the RPI.

The Committee also commissioned a survey of CHSAA member schools asking for their input on the RPI. More than 220 schools responded. That survey showed that:

  • Accuracy is the most important factor in a formula.
  • Schools want more weight on their own winning percentage.
  • Schools believe that RPI should be used to set postseason fields, but not to seed them.

Using this feedback as a guide, the Technology Committee then examined all the RPI data CHSAA has ever captured — including from seasons prior to its implementation in 2016.

Based upon everything it explored and feedback it received, the Technology Committee made the recommendation to move to 30/40/30 because it put more weight on a team's winning percentage, was more accurate than other weights considered, and worked across the spectrum of sports CHSAA offers.