2018 Simulation: Ratings, Ranks, and NCAA Tournament Bracket

Discussion in 'Women's College' started by cpthomas, Aug 17, 2018.

  1. cpthomas

    cpthomas BigSoccer Supporter

    Portland Thorns
    United States
    Jan 10, 2008
    Portland, Oregon
    Nat'l Team:
    United States
    Carrying forward from last year, over the course of the season I'll be running a simulation of the full season. I'll be posting weekly simulated Adjusted RPI ratings and rankings, simulated standings of teams within their conferences and conference tournament results, and a simulated NCAA Tournament bracket. I'll be posting these at the RPI and Bracketology for D1 Women's Soccer Blogspace.

    I've just finished up the four opening posts at the Blogspace:

    If you are interested in following the simulation results, I suggest you read the first post (How I Do It) first, as it describes the process and assumptions that underlie the simulations.

    Early in the season, you have to take the simulation with a very big grain of salt. As the season progresses, each week I substitute actual game results for simulated results. This means that from week to week, the simulation will come progressively closer to how the season will end up.



     
  2. cpthomas

    cpthomas BigSoccer Supporter

    Portland Thorns
    United States
    Jan 10, 2008
    Portland, Oregon
    Nat'l Team:
    United States
    I just have posted my weekly simulation updates at the Blogspace:

    2018 SIMULATED RPI RANKS 8.20.2018

    2018 SIMULATED CONFERENCE STANDINGS AND CONFERENCE TOURNAMENTS 8.20.2018

    2018 SIMULATED NCAA TOURNAMENT BRACKET 8.20.2018

    In addition, at the RPI for Division I Women's Soccer website, on the


    NCAA Tournament: Predicting the Bracket, Track Your Team

    page, I've put an attachment at the bottom of the page that will help you see the details of how each team fares in terms of the NCAA Tournament, within the simulation. If you're a coach or a fan, you can use this to see how your team's simulated record matches up with a whole series of the Women's Soccer Committee's seeding and at large selection decision-making patterns over the last 11 years. The webpage itself includes an explanation of the attachment.

    If you're new to the RPI for Division I Women's Soccer website, you can use the navigation panel on the left to check it out and get lots of information on the NCAA's RPI rating system and process for making NCAA Tournament decisions.

    If you have questions or comments about any of these materials, feel free to post them here or at the Blogspace.


     
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  3. Angry Leprechaun

    Feb 22, 2015
    Club:
    FC Barcelona
    Ok, as a luddite to these simulations...How does one account for the loss of seniors, the incoming freshmen contributors, etc.? Or do you just keep revising as wins and losses roll in and that accounts for it?

    I'm not even getting into an injury to a key player or a key player returning from injury, or teams that develop chemistry vs. those who don't... There seems to be a lot of variables that are hard to plug in.
     
  4. cpthomas

    cpthomas BigSoccer Supporter

    Portland Thorns
    United States
    Jan 10, 2008
    Portland, Oregon
    Nat'l Team:
    United States
    You've got it right. Since the simulation strictly is based on teams' RPI history, it can't take the loss of seniors and the arrival of freshmen into account. It also can't take injuries to key players or key player returns, development of team chemistry, or anything else like that into account.

    You're also right that each week, as I substitute actual game results for simulated results, those kinds of things indirectly will begin to influence the simulated end-of-season results.

    Also, when I have the week 6 games in the system, I stop using teams' RPI history for simulating the results of future games and start using teams' actual RPI ratings for simulating those results. I do this at that time, because that is the time at which using actual RPI ratings produces better correlations with game results than using historic ratings. Those actual RPI ratings presumably are affected by the kinds of things you've mentioned.

    When the season is over, I'll do a comparison of how well the pre-season simulation correlates with the season's actual game results, and will compare that correlation rate to correlation rates for All White Kit's Chris Henderson's predictions and the NCAA soccer coaches' predictions, for those teams for which they've made final ranking predictions (the top 40 or so). I'll also do similar comparisons for teams' standings within their conferences and for AWK's and the simulation's NCAA Tournament bracket predictions. It will be interesting to see how the comparisons come out.
     
  5. Angry Leprechaun

    Feb 22, 2015
    Club:
    FC Barcelona
    Thanks for the insight. Would be also interesting to highlight what teams are overperforming, or underperforming according to their simulation.
     
  6. cpthomas

    cpthomas BigSoccer Supporter

    Portland Thorns
    United States
    Jan 10, 2008
    Portland, Oregon
    Nat'l Team:
    United States
    I just have posted my weekly simulation updates at the Blogspace:

    2018 SIMULATED RPI RANKS 8.27.2018

    2018 SIMULATED CONFERENCE STANDINGS AND CONFERENCE TOURNAMENTS 8.27.2018

    2018 SIMULATED NCAA TOURNAMENT BRACKET 8.27.2018

    In addition, at the RPI for Division I Women's Soccer website, on the

    NCAA Tournament: Predicting the Bracket, Track Your Team

    page, I've put an attachment at the bottom of the page that will help you see the details of how each team fares in terms of the NCAA Tournament, within the simulation. The title of the attachment for this week is 2018 Website Factor Workbook 8.27.2018. If you're a coach or a fan, you can use this to see how your team's simulated record matches up with a whole series of the Women's Soccer Committee's seeding and at large selection decision-making patterns over the last 11 years. The webpage itself includes an explanation of the attachment.
     
  7. cpthomas

    cpthomas BigSoccer Supporter

    Portland Thorns
    United States
    Jan 10, 2008
    Portland, Oregon
    Nat'l Team:
    United States
    I just have posted my weekly simulation updates at the Blogspace:

    2018 SIMULATED RPI RANKS 9.3.2018

    2018 SIMULATED CONFERENCE STANDINGS AND CONFERENCE TOURNAMENTS 9.3.2018

    2018 SIMULATED NCAA TOURNAMENT BRACKET 9.3.2018

    In addition, at the RPI for Division I Women's Soccer website, on the

    NCAA Tournament: Predicting the Bracket, Track Your Team

    page, I've put an attachment at the bottom of the page that will help you see the details of how each team fares in terms of the NCAA Tournament, within the simulation. The title of the attachment for this week is 2018 Website Factor Workbook 9.3.2018. If you're a coach or a fan, you can use this to see how your team's simulated record matches up with a whole series of the Women's Soccer Committee's seeding and at large selection decision-making patterns over the last 11 years. The webpage itself includes an explanation of the attachment.
     
  8. Enzo the Prince

    Sep 9, 2007
    Club:
    CA River Plate
    I'm surprised Notre Dame is projected that highly.
     
  9. cpthomas

    cpthomas BigSoccer Supporter

    Portland Thorns
    United States
    Jan 10, 2008
    Portland, Oregon
    Nat'l Team:
    United States
    It's probably due to two things:

    1. The simulation assumes that the most closely rated ~20% of games will be ties (it shows Notre Dame finishing with 6 ties, which almost certainly is more than they actually will have); and

    2. The simulation shows Notre Dame as having one of the best strengths of schedule.
    For ties, for the most closely rated 20% of games, the higher rated team wins barely more games than the poorer rated team and, figuring in ties, predicting a win for the higher rated team is going to be wrong (the game will be a tie or loss) more often than it will be right. Because of this, I've concluded that assuming those games will be ties, on average, will produce the best match with game results.

    Because of issues like this, as I've stated in this year's initial post at the Blog, you have to take the simulations with a big grain of salt, especially early in the season.
     
  10. Carolina92

    Carolina92 Member

    Sep 26, 2008
  11. cpthomas

    cpthomas BigSoccer Supporter

    Portland Thorns
    United States
    Jan 10, 2008
    Portland, Oregon
    Nat'l Team:
    United States
    I just have posted my weekly simulation updates at the Blogspace:

    2018 SIMULATED RPI RANKS 9.10.2018

    2018 SIMULATED CONFERENCE STANDINGS AND CONFERENCE TOURNAMENTS 9.10.2018

    2018 SIMULATED NCAA TOURNAMENT BRACKET 9.10.2018

    In addition, at the RPI for Division I Women's Soccer website, on the

    NCAA Tournament: Predicting the Bracket, Track Your Team

    page, I've put an attachment at the bottom of the page that will help you see the details of how each team fares in terms of the NCAA Tournament, within the simulation. The title of the attachment for this week is 2018 Website Factor Workbook 9.10.2018. If you're a coach or a fan, you can use this to see how your team's simulated record matches up with a whole series of the Women's Soccer Committee's seeding and at large selection decision-making patterns over the last 11 years. The webpage itself includes an explanation of the attachment.
     
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  12. cpthomas

    cpthomas BigSoccer Supporter

    Portland Thorns
    United States
    Jan 10, 2008
    Portland, Oregon
    Nat'l Team:
    United States
    In case anyone notices that the NCAA has released three RPI reports at its RPI Archive:

    The reports indicate that they cover games through September 16. A close look, however, shows that they are missing a good number of games played this last weekend. They apparently ran the reports before all schools had gotten their data entered into the system. These include some major players in the rankings. Because of this, what you're seeing in the reports does not correctly represent where things are based on all games played through September 16. Hopefully the NCAA will fix this and issue new reports.
     
  13. cpthomas

    cpthomas BigSoccer Supporter

    Portland Thorns
    United States
    Jan 10, 2008
    Portland, Oregon
    Nat'l Team:
    United States
    UPDATE: The NCAA staff is aware of this problem and are working on it, hoping to post updated reports at the RPI Archive later today.

    PS - the NCAA staff is great on stuff like this.
     
  14. Collegewhispers

    Oct 27, 2011
    Club:
    Columbus Crew
    Do you have a link to this rpi page?
     
  15. Kurt Kline

    Kurt Kline Member

    Ajax
    United States
    Jun 26, 2012
    Yorba Linda, CA
    Club:
    FC Barcelona
    Nat'l Team:
    United States
  16. cpthomas

    cpthomas BigSoccer Supporter

    Portland Thorns
    United States
    Jan 10, 2008
    Portland, Oregon
    Nat'l Team:
    United States
    Here is the link to the RPI Archive, which is different than the weekly RPI ranks that the NCAA publishes at NCAA.com. The RPI Archive is where you go for detailed RPI-related data. If you really want to delve into the data, you go to the Team Sheets reports posted at the Archive.

    RPI Archive

    Once there, you may have to fill in the query boxes to get to the D1 women's soccer reports although as of right now they're at the top of the list if you just use the above link.
     
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  17. cpthomas

    cpthomas BigSoccer Supporter

    Portland Thorns
    United States
    Jan 10, 2008
    Portland, Oregon
    Nat'l Team:
    United States
    I'll post my weekly reports tomorrow. I go distracted today by the NCAA's problems getting this weekend's full data into their system and haven't had time to get all my reports together.

    Let me say, the NCAA staff work really hard. I'm sure they'll figure this out. They are very dedicated and do a really good job.
     
  18. cpthomas

    cpthomas BigSoccer Supporter

    Portland Thorns
    United States
    Jan 10, 2008
    Portland, Oregon
    Nat'l Team:
    United States
    On just checking, the NCAA has not yet published updated and corrected RPI reports at the RPI Archive, covering games played through September 16. If you want to see RPI information covering teams through those games, I've published my first weekly RPI report on the RPI website's RPI: This Year's Reports page. The report is an Excel workbook attachment at the bottom of that page titled 2018 RPI Report 9.17.18. It includes the details of teams RPI ratings and also of their Non-Conference RPI ratings. It also shows the conferences' average RPIs and NCRPIs. And finally, it shows regional playing pool average RPIs and NCRPIs (based on actual playing pools, not on the NCAA's regional framework).

    Ordinarily, I prefer not to publish that report until I've had a chance to compare my ratings to the NCAA's and to be sure the two match. With the NCAA's currently published reports for this week being well off the mark, I've gone ahead now with my publication.

    You also can get RPI ratings updated daily, and lots of other good current information, at All White Kit's 2018 College Women's Soccer Schedule website. As of games through September 16, my numbers and theirs match exactly (except for some completely minor 0.0001 differences due to differences in computer programs' rounding conventions).
     
  19. cpthomas

    cpthomas BigSoccer Supporter

    Portland Thorns
    United States
    Jan 10, 2008
    Portland, Oregon
    Nat'l Team:
    United States
    I just have posted my weekly simulation updates at the Blogspace, including an actual ARPI rankings table since it's the stage of the season where ARPI rankings begin to have some meaning:

    2018 RPI REPORT 9.17.2018

    2018 SIMULATED RPI RANKS 9.17.2018

    2018 SIMULATED CONFERENCE STANDINGS AND CONFERENCE TOURNAMENTS 9.17.2018

    2018 SIMULATED NCAA TOURNAMENT BRACKET 9.17.2018

    In addition, at the RPI for Division I Women's Soccer website, on the

    NCAA Tournament: Predicting the Bracket, Track Your Team

    page, I've put an attachment at the bottom of the page that will help you see the details of how each team fares in terms of the NCAA Tournament, within the simulation. The title of the attachment for this week is 2018 Website Factor Workbook 9.17.2018. If you're a coach or a fan, you can use this to see how your team's simulated record matches up with a whole series of the Women's Soccer Committee's seeding and at large selection decision-making patterns over the last 11 years. The webpage itself includes an explanation of the attachment.
     
  20. Kurt Kline

    Kurt Kline Member

    Ajax
    United States
    Jun 26, 2012
    Yorba Linda, CA
    Club:
    FC Barcelona
    Nat'l Team:
    United States
    Which source of information is used to determine NCAA tournament invites?
     
  21. cpthomas

    cpthomas BigSoccer Supporter

    Portland Thorns
    United States
    Jan 10, 2008
    Portland, Oregon
    Nat'l Team:
    United States
    The RPI Archive reports are what the Committee uses for NCAA Tournament at large selections and seeding. Right now, there are three reports up at the Archive (whose details aren't correct because of a problem their system is having), but there are other related reports the Committee also gets. Ultimately, all these reports should be available at the Archive.

    I believe the Archive's Team Sheets is the report that gets the most use by the Committee.

    If you're interested in the detail of how the NCAA Tournament process works, I suggest you go to the RPI for Division I Women's Soccer website and work your way through the NCAA Tournament pages, starting with this one: NCAA Tournament: Selection, Seeding, and Bracketing Criteria
     
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  22. Kurt Kline

    Kurt Kline Member

    Ajax
    United States
    Jun 26, 2012
    Yorba Linda, CA
    Club:
    FC Barcelona
    Nat'l Team:
    United States
    Thank you very much!
     
  23. cpthomas

    cpthomas BigSoccer Supporter

    Portland Thorns
    United States
    Jan 10, 2008
    Portland, Oregon
    Nat'l Team:
    United States
    I just have posted my weekly simulation updates at the Blogspace, including an actual ARPI rankings table since it's the stage of the season where ARPI rankings begin to have some meaning:

    2018 RPI REPORT 9.24.2018

    2018 SIMULATED RPI RANKS 9.24.2018

    2018 SIMULATED CONFERENCE STANDINGS AND CONFERENCE TOURNAMENTS 9.24.2018

    2018 SIMULATED NCAA TOURNAMENT BRACKET 9.24.2018

    In addition, at the RPI for Division I Women's Soccer website, on the

    NCAA Tournament: Predicting the Bracket, Track Your Team

    page, I've put an attachment at the bottom of the page that will help you see the details of how each team fares in terms of the NCAA Tournament, within the simulation. The title of the attachment for this week is 2018 Website Factor Workbook 9.24.2018. If you're a coach or a fan, you can use this to see how your team's simulated record matches up with a whole series of the Women's Soccer Committee's seeding and at large selection decision-making patterns over the last 11 years. The webpage itself includes an explanation of the attachment.
     
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  24. Carolina92

    Carolina92 Member

    Sep 26, 2008
    Which RPI element is SOS again? Would be interesting to see that ranking now that we're halfway through the season and getting into the meat of conference play.
     
  25. sokarcrazy

    sokarcrazy Member

    Dec 19, 2005
    Since non conference play is almost done do you have a conference strength ranking?
     

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