The acronym RPI usually is reserved for March when college basketball talking heads project which bubble teams are in or out of the NCAA tournament.
Well, the RPI has trickled down to high school football in Iowa.
The Iowa High School Athletic Association has released Ratings Percentage Index football rankings every Monday for the past month.
I refused to open the link for the first couple of weeks because the sample size was too small. I received a couple of emails from individuals complaining about the validity of the rankings.
My response was get back to me in mid-October.
So as we embark upon the final two weeks of the regular season, it is time to give these rankings serious attention.
The RPI, endorsed by the Iowa Football Coaches Association last winter, will be used for the first time this year to determine at-large playoff qualifiers in Iowa for all six classes.
The Colorado High School Activities Association debuted a similar system two years ago and the reviews have been mostly favorable.
According to the postseason manual the IHSAA released this week, the RPI also will be used to determine brackets for first-round and quarterfinal contests and which schools host postseason games.
So, yeah, the RPI has significant importance in deciding which schools get to the UNI-Dome and vie for a state championship next month.
How is each school's RPI computed? Simply, it is based 37.5 percent on a team's winning percentage, 37.5 on its opponents' winning percentage and 25 percent on its opponents' opponents' winning percentage.
Unlike the past where the 17-point differential was applied, margin of victory means zilch. A win by one carries the same weight as a continuous-clock triumph.
A home win is worth the same as a road victory.
There also is no reward for a school beating a team in a higher classification. Class 3A North Scott gets equal credit for defeating Central DeWitt (4-3) as it did for blitzing 4A Davenport Central (4-3).
The playoff field in each class consists of 16 teams. All district champions are automatic qualifiers. If there are multiple teams tied for the top spot in a district, they all advance.
In 4A, there are seven districts. If there is just one champion in each district, that would leave nine at-large berths. Those nine spots will be filled using the RPI, which takes all nine games into account.
Heading into this week's games, there are 11 teams in 4A leading a district — Dowling Catholic, Ankeny Centennial, Cedar Falls, Cedar Rapids Prairie, Iowa City West, Bettendorf, Davenport Central, Johnston, Waukee, West Des Moines Valley and Ames.
The list will thin out the next two weeks as several of these teams square off.
But looking at current projections, those 11 schools would be in the postseason along with five at-large qualifiers. Indianola, Fort Dodge, Davenport North, Pleasant Valley and Muscatine are the top five in this week's RPI not at the top of a district.
If PV, which started the season 0-3, can win its next two games against Davenport North and Linn-Mar to finish 5-4, the Spartans have a legitimate shot at being in the playoffs.
In 3A, there are 12 teams leading or co-leading a district. North Scott is among them.
Assumption is 31st in the RPI, but there is still a path to the playoffs. If the Knights win out and North Scott beats Clear Creek-Amana this Friday, Assumption would be at least a co-district champion.
West Liberty, in 2A, is 21st in the RPI and stands a minimal chance of getting an at-large bid. The Comets (4-3), however, are in sole possession of the district lead and are virtually in if they win one of their last two games.
District leaders Bellevue (7-0) and Wilton (6-1) are third and 10th, respectively, in the 1A rankings.
Durant, tied for the district lead with BGM (Brooklyn), is sixth in A — the best of any two-loss team.
For the opening round of the postseason in 4A, the seven district champs have an opportunity to host along with the at-large team with the highest RPI.
In 3A, 2A and 1A where there are nine districts, the lowest RPI team of the nine champions will travel. There will be two district champions to travel in A, which is comprised of 10 districts.
Geography will be a factor, so it won't be a true 1 vs. 16, 8 vs. 9 bracket. You won't have an at-large qualifier from central Iowa visiting Bettendorf's TouVelle Stadium in the first round.
I have no qualms about the RPI determining playoff qualifiers. The biggest flaw is using it to decide home playoff games rather than factoring in head-to-head results.
For instance in this week's RPI, the top four teams in the eastern half of 4A are Cedar Falls (No. 2), Iowa City West (No. 4), Bettendorf (No. 6) and Cedar Rapids Prairie (No. 7).
It would be logical for the state to have a preset bracket where Cedar Falls could play Prairie in one quarterfinal and Iowa City West vs. Bettendorf in another.
Even though Bettendorf owns a 10-7 win over West in Week 2 and both programs likely capture district titles and have identical records, the game would be in Iowa City (as of now) based on RPI.
I'm not certain the RPI accurately reflects the best teams. Dowling beat Johnston 27-0 in Week 3. Currently, Johnston is fifth and Dowling ninth in the rankings.
Dowling does have two losses, but they were to top-ranked West Des Moines Valley and third-ranked Ankeny Centennial in the non-district. Johnston's three non-district wins are against teams a collective 11-10.
The other new wrinkle comes in the semifinal round.
In the past, the top two teams from central Iowa often match up in one 4A semifinal and the two best from the eastern half meet in the other.
Now, the IHSAA will seed the four remaining teams using its RPI after Week 9 games. The top RPI team plays No. 4 and No. 2 squares off with No. 3.
So a Valley vs. Dowling or Bettendorf vs. Cedar Falls rematch is viable in the championship game.
There is a lot to digest.
The IHSAA admitted there could be some tweaks to the system in future years. This is a starting point.
Let's see how it pans out this season before we rush to judgment. I applaud the IHSAA and Iowa Football Coaches Association for ditching the point-differential rule and being open to something new.
Regardless, the next few weeks should provide plenty of intrigue.