RPI Question

[AvidSportsJunkie856]

I was looking at the RPI system (yes I know it is kind of terrible) and had a question as I was looking at some different team's current RPI ratings.

If a team from a lower class (we will use 5A) were to play against the worst 6A team and beat them - would that give them more RPI points than playing and beating one of the best 5A teams in their own class? 

[TimeWillTell]

3 minutes ago, AvidSportsJunkie856 said:

I was looking at the RPI system (yes I know it is kind of terrible) and had a question as I was looking at some different team's current RPI ratings.

If a team from a lower class (we will use 5A) were to play against the worst 6A team and beat them - would that give them more RPI points than playing and beating one of the best 5A teams in their own class? 

Yes. 

[AvidSportsJunkie856]

2 hours ago, TimeWillTell said:

Yes. 

Thank you. I don't know if this needed its own thread as it was a simple question with a simple answer!- seems like that is one of many flaws in the RPI system. 
 

[Voice of Reason]

This may be too much info, but for anyone who is interested, here is how RPI weights game value for football. Before I get into the details, here is the issue. How do you factor in class size to RPI? Below is KHSAA's formula. The WP part of the formula does not care how good or how bad the teams are. It only cares about school size. Beating Trinity has the same game value as beating Eastern. I will leave that there for now. Here is how RPI factors in school size to game value and winning percentage:

chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://khsaa.org/common_documents/RPI/rpiexample2018fbapb.pdf

The game value factors are:

1A = 1.323

2A = 1.521

3A = 1.749

4A = 2.011

5A = 2.313

6A = 2.660 

Kentucky has six football classes, 1A through 6A, which generally reflects the enrollment of the school. The WP calculations are adjusted to give more weight to a game when a school "Plays Up" by playing a higher class and give less weight to games when a school "Plays Down" by playing a lower class.

This weight is used to adjust the value of a win depending on the team's class and the opponent's class. If the game is a win for the team, the Winning Percentage of the game is the class weight (the Winning Value in the example) for the opponent divided by the class weight of the team (the Game Value in the example). This gives the Winning Percentage for that game. 

Example:

A 4A school (2.011) beats a 4A school (2.011). The WP for that game is 2.011/2.011 x 1 = 1

A 4A school (2.011) loses to a 4A school (2.011). The WP for that game is 2.011/2.011 x 0 = 0

A 4A school (2.011) beats a 1A school (1.323). The WP for that game is 1.323/2.011 x 1 = 0.65788

A 4A school (2.011) beats a 6A school (2.660). The WP for that game is 2.660/2.011 x 1 = 1.32272

Let me summarize.

If a team loses a game, that is a zero to the team's winning percentage (WP). Class size or quality of opponent doesn't matter. Losing to Trinity by 1 point is the same as losing to Eastern by 35.

If a team wins a game, the value of that win is determined by what class the team is in and what class the opponent is in. Quality of opponent is not a factor in WP, only the class size.

 

 

 

 

[Tigerpride94]

Also have this exemption:

 

Beginning with the 2023 season, the first two contests of the year played against a team in a smaller class will not have the opponent’s class factor applied within the OWP and thus, OOWP calculation but will instead be treated as both teams being in the same class.

[Footballfan24]

I have a limited knowledge of how RPI works but I do have some knowledge. The above post clears it up a little more. What I do not understand is how a team with two losses but wins over two teams with 3 losses ends behind them in RPI going into week 9.  T beats FD and X and lands behind them in the current ranking.  

Another questions I have; If lower levels get multipliers for playing higher level teams Shouldn't they be around the same RPI numbers as the teams they play? For example South Warren would be in 6th place in RPI this morning in 4A.  If we are really trying to rank the teams on performance and every team gets scored the same way, how does 6A #1 SW land in sixth place if they were in the 4A bracket? 

[Tigerpride94]

1 hour ago, Footballfan24 said:

I have a limited knowledge of how RPI works but I do have some knowledge. The above post clears it up a little more. What I do not understand is how a team with two losses but wins over two teams with 3 losses ends behind them in RPI going into week 9.  T beats FD and X and lands behind them in the current ranking.  

Another questions I have; If lower levels get multipliers for playing higher level teams Shouldn't they be around the same RPI numbers as the teams they play? For example South Warren would be in 6th place in RPI this morning in 4A.  If we are really trying to rank the teams on performance and every team gets scored the same way, how does 6A #1 SW land in sixth place if they were in the 4A bracket? 

Trinity is getting hurt by schedule strength because of the out of state teams and PRP being 1-7 and also Eastern being bad. The lower class teams that have higher RPI than 6A is because of the class multiplier so when Boyle County beat St. X they got extra points instead of the 4A level points, but many more examples of lower class team beating higher class and getting extra points. 

[theguru]

From the KHSAA:

RPI Background (all sports)

RPI stands for Ratings Percentage Index.
RPI is used for district tiebreaking and football third, fourth and fifth-round bracketing, as well as a means to increase publicity, interest and promotion of interscholastic athletics.
RPI is also used as a tiebreaking/contest-result mechanism to decide seeded district games that are not played by the deadline.
The KHSAA is uniquely positioned to be the sole and authenticated source of RPI data due to the maintenance of required score reporting and scoreboard data for baseball, basketball, field hockey, football, soccer, softball and volleyball for more than two decades.
RPI rankings are updated on an hourly basis but are not calculated for teams with missing scores from previous or multiple contests.
The RPI formula is modeled after, but not identical to, similar measurement tools (e.g., NCAA, NAIA, etc.).
RPI measures a team’s strength relative to other teams, based largely on the strength of its schedule (margin of victory is not a factor).
RPI is calculated from the team’s winning percentage (WP), the opponents’ winning percentage (OWP) and the opponents’ opponents’ winning percentage (OOWP).
RPI is calculated from the team’s winning percentage (WP), the opponents’ winning percentage (OWP) and the opponents’ opponents’ winning percentage (OOWP).
These three components are combined to produce the RPI using the following formula: RPI = (WP * WPVAL) + (OWP * OWPVAL) + (OOWP * OOWPVAL).
WPVAL shall be .35 (35%).
OWPVAL shall be .35 (35%).
OOWPVAL shall be .30 (30%).
An RPI of 0 is likely not possible in any scenario. From a mathematical perspective, a team would have to be winless, each of their opponents winless, and each of their opponents’ opponents winless.

 

Basic RPI Calculations (Football)

In football, the following values are assigned to game results when calculating WP throughout the compilation:
A win is assigned a value of 1.0 as a basis for comparison.
A tie is assigned a value of 0.5.
A loss is assigned a 0.0 value.
In addition, football has a class factor added to the formula and special situations for when that is and it not applied.
Non_KHSAA Factor (football)
For football only, the non-KHSAA value is set to a fixed value based on pre-COVID competition results.
That value is .51060 and is reviewed following each season.
Due to the limited number of contests for football compared to the other sports and the fact that football is divided into classes, and as the KHSAA office maintains the official district standings, there are additional clarifications and operations in football that are not necessary for other sports, as follows:
A team is eligible to play 10 contests during the 11-week season;
All games played, including forfeits, count as normal with RPI;
A seeded district or contracted game unable to be played without forfeit attribution will be decided by comparative RPI following the last regular-season game;
A class factor is applied to the football RPI calculations through the WP calculation;
Beginning with the 2023 season, the first two contests of the year played against a team in a smaller class will not have the opponent’s class factor applied within the OWP and thus, OOWP calculation but will instead be treated as both teams being in the same class.
However, all contests played against opponents in a higher class will have the class factor applied to the more highly classified opponent.
With this new provision for two play-downs, when calculating OWP and OOWP in football, there are no “Playing Down” exemptions.
Winning Percentage Calculation for Football
Football is a special case, and enhancements are made to the winning percentages.
These percentages are adjusted by multiplying by a game value based on the class of the opponent in football, primarily due to the limited number of opportunities to play contests and to compensate for schools playing in a different class than they might otherwise be placed by enrollment.
It should also be noted that by using class weights, as is done in football, it is possible to get WP greater than 1.000 but less likely in the higher class listings due to less opportunities for playing up.
It is possible to get OWP, OOWP, and even RPI that is greater than 1.000 due to class weights.
Kentucky has six football classes, Classes 1-6A, which generally reflects the enrollment of the school.
The WP calculations are adjusted to give more weight to a game when a school “Plays Up” by playing a higher class and give less weight to games when a school “Plays Down” by playing a lower class (after exhausting two allowed “Playing Down” exemptions beginning in 2023-24).
This weight is used to adjust the value of a win depending on the team’s class and the opponent’s class.
If the game is a win for the team, the Winning Percentage of the game is the class weight (the Winning Value in the example) for the opponent divided by the class weight of the team (the Game Value in the example). This gives the Winning Percentage for that game.
Consider the game between Ashland Blazer and Harlan County in the published example. Ashland Blazer (a Class 4A team) won against Harlan County (a Class 5A team). So, the Winning Percentage for this game is 2.313/2.011 = 1.15017. On the other hand, consider the game between Ashland Blazer and Russell (a Class 3A team). Ashland won this game, too. So, the Winning Percentage of this game is 1.749/2.011 = 0.86972 (assuming this game occurred after Ashland Blazer had exhausted its two allowed “Playing Down” exemptions).
This produces the desired outcome as Ashland Blazer “played up” in class when it played Harlan County, so the Winning Percentage of that game is greater than the win against Russell because Ashland Blazer “played down” in class.

https://khsaa.org/rpi-calculation-steps/

[16thBBall Fan]

Hey @AvidSportsJunkie856I am a big Frederick Douglass guy since their inception but here is all you need to know about RPI and how flawed it is. Currently after last night's game in 6A Douglass is #4 at .61277 and Trinity is at #5 .60762 and they beat Douglass with a running clock 37-0.

[Footballfan24]

I'm not sure that there is enough weight put on head to head wins. Give a multiplier to district champs? I am just spit balling here to figure out a way to better reflect the competition amongst the top 5 or 6 teams in each class.  X will win the district but have to go to Manual in the playoffs. That does not sit well with the purist in me. RPI would still play factor and the multiplier

may not make a difference but it may offset some of the penalty of having play less than par teams in your district. 

[Tigerpride94]

30 minutes ago, Footballfan24 said:

I'm not sure that there is enough weight put on head to head wins. Give a multiplier to district champs? I am just spit balling here to figure out a way to better reflect the competition amongst the top 5 or 6 teams in each class.  X will win the district but have to go to Manual in the playoffs. That does not sit well with the purist in me. RPI would still play factor and the multiplier

may not make a difference but it may offset some of the penalty of having play less than par teams in your district. 

Maybe could use RPI for matchups but use head to head matchup to determine who is home team. If no head to head matchup to use then just use RPI.

[Rebel]

1 hour ago, 16thBBall Fan said:

Hey @AvidSportsJunkie856I am a big Frederick Douglass guy since their inception but here is all you need to know about RPI and how flawed it is. Currently after last night's game in 6A Douglass is #4 at .61277 and Trinity is at #5 .60762 and they beat Douglass with a running clock 37-0.

Another example would be that no ONE would have Covington Catholic at #11th. in any 4A poll.  RPI does.  I do like the concept of the RPI over if it was just your regions time to host a playoff game.   It just needs some adjustments IMO.  Couple of years ago Lex Cath beat Boyle in the regular season but come week 3 in the playoffs Boyle had a higher RPI and got to host the rematch game.  

[theguru]

3 minutes ago, Rebel said:

Another example would be that no ONE would have Covington Catholic at #11th. in any 4A poll.  RPI does.  I do like the concept of the RPI over if it was just your regions time to host a playoff game.   It just needs some adjustments IMO.  Couple of years ago Lex Cath beat Boyle in the regular season but come week 3 in the playoffs Boyle had a higher RPI and got to host the rematch game.  

Agree 100% and I think it would be tough to make a case for CCH to be any lower than they are in our rankings:

Class 4A
1. Boyle County
2. Highlands
3. Covington Catholic
4. Johnson Central
5. Franklin County
6. Paducah Tilghman
7. Corbin
8. North Oldham
9. Logan County 
10. Ashland

[Breds82]

Outside of challenging your team, if I’m a 1A team, why not just schedule 4-6A schools you k so you can beat?

[Rebel]

4 minutes ago, theguru said:

Agree 100% and I think it would be tough to make a case for CCH to be any lower than they are in our rankings:

Class 4A
1. Boyle County
2. Highlands
3. Covington Catholic
4. Johnson Central
5. Franklin County
6. Paducah Tilghman
7. Corbin
8. North Oldham
9. Logan County 
10. Ashland

Just me but I think Covington Catholic is the best team in 4A and has the hardest road ahead of them in the playoffs.  Host a opening round playoff game and will have to go on the road for week 2,3, & 4 just to make the Championship game.