Washington’s Rating Percentage Index (RPI)
Frequently Asked Questions
Go To RPI Rankings page
What is RPI?
RPI, Rating Percentage Index is a statistical system used to comparatively rank teams.
What is the purpose of the RPI?
The purpose of the RPI is to seed teams into the regional and state basketball brackets using this statistical system.
What is the formula of the RPI?
The formula used is as follows: RPI = (25% x WP) + (50% x OWP) + (25% x OOWP)
- WP (Winning Percentage): Divide the number of wins by the number of total games played for your team.
- OWP (Opponents Winning Percentage): Average of the winning percentage of a team’s opponents (Note: this is not calculated via the combined record of the opponents, but rather by averaging the winning percentage of the opponents).
- OOWP (Opponents’ Opponents Winning Percentage: Same process as OWP except the calculation is with the opponents of the team’s opponent. Note: there is an exception for out-of-state opponents – see below.
How will out-of-state opponents be calculated?
Out of state opponents winning percentage will be calculated at .500.
Why use the RPI vs what has been used previously?
The RPI system will be an accurate reflection of all regular season games. Teams will be seeded into the regional bracket based on their RPI ranking versus previous criteria that was based on how teams finished in the District qualifying tournaments.
Will postseason games be taken into consideration?
No, since there is such a variety in the number of games played during the league and/or District tournaments, those games will not be included in the RPI.
Will teams be re-ranked after the regional round?
Teams will be seeded using the RPI for the regional round only. Teams that qualify for the state bracket will assume the RPI from the regional round. Re-seeding will not be done following the regional round.
What is important to make RPI successful?
Score reporting is essential for an accurate RPI. Scores will be collected in MaxPreps. The WIAA will publish the RPI on its website. Any other publication sites may not be accurate.
Where should scores be reported?
Scores must be reported on MaxPreps. The official RPI will be based on the scores reported.
Should scores from the jamboree be reported?
No, only scores from full games should be reported.
How will the RPI be published?
The RPI will be published on the WIAA website.
How will a team know its ranking?
The rankings will be published beginning the first week in January, 2017. Rankings will be updated daily and published on the WIAA website.
Will it be used for other WIAA sports?
The RPI will be used for basketball only this year. RPI could expand into other sports as soon as next year.
Is the RPI for all classifications?
The RPI will be used for all classifications in basketball this year.
What is the impact of cross-classification games?
The formula does not take into account classifications. A team will not be penalized for playing a team in a lower classification nor rewarded for playing against a team in a higher classification (see how the formula is calculated above).
Does the score differential matter in the RPI?
The RPI is based on a win loss formula (see above). Score differential will have no bearing on the RPI.
What if teams have a different amount of games?
The RPI formula works off the averages of three components: winning percentage, opponent winning percentage and opponents’ opponents winning percentage, so an imbalance of one or two games between teams will have virtually no impact on the ranking system.
Is a team’s RPI based on the opponent’s record at the time the game is played or is the RPI based on the final regular season record of their opponents?
The final RPI calculations used for seeding purposes will be based on the final regular season records of all teams.
How will ties be broken?
A five-step tie-breaking criteria will be utilized to break any ties:
- 1st – RPI score/ranking, taking the value out to as many places as needed (versus only three places)
- 2nd – results of head to head competition (regular season only)
- 3rd – winning percentage (WP)
- 4th – strength of schedule
- 5th – coin flip
With so many unknowns, why didn't the WIAA pilot the RPI for 1 year to see how accurate it is?
Three reasons. One, the results of a survey conducted showed that the majority of the Superintendents, Principals, AD's and Coaches that responded favored an RPI and preferred that it be implemented this year. Second, experience shows that if the RPI was only considered a pilot, getting all results posted and thus accurate results would be a problem. Finally, with the help of a statistician, the basketball committee tested the RPI with last year's 3A boys regular season results and found the RPI fairly accurate.
Why do postseason games not count toward our RPI?
There is a vast difference in postseason qualifying tournaments around the state. In looking at teams that made the round of 16 in 2016, teams played as few as two postseason games while others played as many as ten. The RPI committee felt this wide discrepancy may not make it a level playing field for all. The committee will be closely examining this issue and may make changes for next year.
My team is scheduled to play in a 3rd/4th place consolation game at our district tournament. Both teams are advancing to the Regionals and RPI will seed us no matter who wins the consolation game. Why should we play this game and risk injury?
A concern the RPI committee has this year will be the effect RPI has on district qualifying tournaments. The committee understands the importance of postseason tournaments to the leagues. Understanding that coaches may wish to rest key players or not want to play consolation games, the hope is that teams will find value in playing in a competitive tournament game with a tournament atmosphere to help prepare for Regionals. As always, the committee will study the effect RPI has on postseason tournaments and evaluate possible improvements.
We play several successful out-of-state opponents to fill out our schedule. Treating these opponents as .500 teams will hurt our RPI. Why can't we count their true records?
The success of any RPI/ranking system depends on accurate results being posted. The feedback from other states is that getting accurate results from the in-state teams is a challenge, let alone trying to track down the records of all out-of-state opponents. In order to remove this dynamic in year one, the RPI committee decided to count out-of-state teams as .500. Developing a method to accurately track out-of-state opponents records will be a task the committee will be studying for year two.
How is the strength of schedule (SOS) determined?
SOS is .5*OWP+.25*OOWP
When I try to calculate teams OWP, I get different results than what is shown on th RPI page? How is OWP calculated?
OWP is the average winning percentages of a team's opponents. (Note: This is not calculated via the combined record of the opponents, but rather averaging each winning percentage of the opponents.) It is also important to remember that when calculating OWP (and OOWP), the head-to-head matchup between teams is taken out of the equation. That game already is figured in both teams' WP. The RPI rationale for omitting that is so there isn't a double bonus or a double hit for that specific game to the teams, and you get an accurate reading of how teams rate when they are not playing each other.
Our district gets 4 teams to Regionals. My team earned 4th place in our district tournament, but finished with an RPI at #17 in the final rankings. Does that mean my team is out of the tournament?
Your team is in. District tournaments and allocations still determine the 16 teams that qualify for the Regional games. The RPI is only used to seed those 16 teams into the Regional bracket. There will be instances when a top 16 team according to RPI does not qualify for Regionals. The next highest ranked team according to RPI will move and take over their seed. For instance, if the #1 - 5 qualifies but #6 does not qualify, the #7 team would move up to become the #6 seed in the Regional bracket. This would be done until all 16 teams are seeded.