(1-2-25) Below is a lot of background on the MaxPreps Basketball RPI formula. Included is several portions from Ohio High School Basketball Coaches Association (OHSBCA) Newsletters and from the Ohio High School Athletic Association (OHSAA) web site.

The very legitimate question left unanswered is why was it was decided that all out-of-state opponents given a D IV value of 1.55 points?

Also what is the arrangement between MaxPreps, OHSAA and OHSBCA to use the current RPI system, that puts the burden of work on reporting stats an scores on each OHSAA member?

OHSAA Basketball using MaxPreps for RPI Data Collection and Seedings
The Ohio High School Athletic Association has decided that Ratings Percentage Index is a more accurate way to seed teams for the OHSAA Tournament and it will be employed in basketball this winter. MaxPreps can calculate RPI based on strength of schedules and has offered to provide this service for the sport of basketball for the 2023-24 season. The intent of this new data collection is to employ a more equitable way to determine a team’s postseason seed. Below is the basic formula that will be used. 

The RPI formula is = (0.40 × WP) + (0.35 × OWP) + (0.25 × OOWP). 

• Winning percentage (WP): Divide the number of wins by the number of total games played. A tie is worth half a win. If a win in an individual contest gives that contest a winning percentage of 1.00, a tie would give that individual contest a winning percentage of .500 for both teams.

• Opponents’ winning percentage (OWP): Average the winning percentages of a team’s opponents. (Note: This is not calculated via the combined record of the opponents, instead by averaging each
winning percentage of the opponents.) All games involving the team whose RPI is being calculated are ignored in this process.

• Opponents’ opponents winning percentage (OOWP): The same process as described above, except calculated for the opponents of a team’s opponents. Note that there is an exception for out-of-state
teams, which is addressed below.

This is the RPI at its purest form which is based on wins, losses and strength of schedule with no filters (i.e. class size, etc.). Each game will count as 1 point (ties are worth 0.5 to each team for win and loss.). Out-of-state teams are weighted the same as in-state teams. Non-varsity and non-member schools (i.e. prep schools, Canadian schools, etc.) are not included in the RPI calculation. Further review of these parameters may be considered, but simplicity is the focus for this initial season.

The official OHSAA RPI standings will be published on OHSAA.org. It is worth noting that any RPI data published elsewhere is unofficial and should be viewed with skepticism as it may not be correct. The OHSAA RPI data should not be confused with the MaxPreps rankings. MaxPreps rankings are updated twice a week and posted on http://www.maxpreps.com.

The RPI standings will not be published for the first time until mid-January. This is to allow teams to have at least competed in a few games to have RPI data. Once they are posted, feeds are updated daily during the remaining regular season.

A major advantage to the RPI is the transparency that comes along with its accuracy. The components of the formula are known, and its results can be easily replicated.

Essentially, only one school needs to report the score into MaxPreps, but we recommend each school check scores daily to see which games are missing results. MaxPreps also can monitor accounts so school participation can be tracked for those not entering results. If this becomes required, it will be easy to identify schools not participating and the OHSAA may administer fines.

The above is from the OHSBCA (October, 2023) Newsletter – https://oh.nhsbca.org/news/author/pat-carroll

RPI Rating System
The Ohio High School Basketball Coaches Association has worked with Max Preps on the RPI Formula that will be used for the 2024-2025 basketball season. Through feedback from coaches and district directors, this year the formula will be composed of three components – Percentages for RPI, Points of Classifications, and Out of State Points.

First component is the Percentages for the RPI. The Percentages for RPI is based on WP (Winning Percentage), OWP (Opponents Winning Percentage), and OOWP (Opponents Opponents Winning Percentage). The formula will be 40%WP x 40%OWP x 20% OOWP.

The second component will be Points of Classification.  Division 1 – 2 points, Division 2 – 1.85 points, Division 3 – 1.70, Division 4 – 1.55, Division 5 – 1.40, Division 6, 1.25, and Division 7 – 1.10.

The third component is based on out-(of)-state opponents. The point value of 1.55 points will be awarded.

The OHSBCA and coaches will be monitoring the effects of these changes to the rating system and will re-evaluate at the end of the season.

The above is from the OHSBCA (October, 2024) Newsletter – https://oh.nhsbca.org/news/coaches-association-newsletter-2024-october

We will again be using the Max Preps RPI for the seeding of our tournaments this year. The OHSBCA District Directors made some adjustments by changing the percentages to 40% WP (Winning Percentage) – 40% OWP (Opponents Winning Percentage) – 20% OOWP (Opponent’s Opponent Winning Percentage). A second component of points of classification was added for each division, and a third component for out-of-state opponents was also added. You are reminded that the RPI will only be used for
seeding purposes it will not determine teams’ placement on the tournament bracket. You are also reminded to report all your scores to Max Preps. The initial Max Preps RPI will be released the week of January 6th.

The above is from the OHSBCA (December, 2024) Newsletter – https://oh.nhsbca.org/news/coaches-association-newsletter-2024-december

Above located on the OHSAA web site —- https://ohsaaweb.blob.core.windows.net/files/Sports/BasketballManual.pdf

Above located on the OHSAA web site —- https://ohsaaweb.blob.core.windows.net/files/Sports/Basketball-Boys/2024-25/OHSAA-BasketballRPI-2025.pdf

The concept of using RPI to determine seeding was proposed by the Ohio Basketball Coaches Association (OHSBCA) and approved by the OHSAA Board of Directors last fall (2023). 

The RPI formula was recommended by the OHSBCA, adopted by the OHSAA and is calculated using scores entered into MaxPreps. The formula is comprised of 40 percent winning percentage, 35 percent opponent’s winning percentage, and 25 percent opponent’s opponent’s winning percentage. The winning team is required to enter the score into MaxPreps, or for out-of-state opponents, the Ohio school must enter the score if it is not entered by the out-of-state school.

Above located on the OHSAA web site (January, 2024) —- https://www.ohsaa.org/news-media/ohsaa-releases-updated-basketball-rpi-rankings