Unofficial MIAA Girls Basketball Power Rankings – January 1, 2023
The Massachusetts Interscholastic Athletic Association (MIAA) moved to a Statewide tournament across all sports starting in the 2021-2022 season. That meant having a scoring formula for each sport to create an RPI like rating to rank teams by division for each sport for the statewide tournament.
As a fan of spreadsheets and data and a girls basketball coach at Saugus, I was interested to see if I could recreate the ranking system for the 2022-2023 tournament and provide directionally accurate power rankings during the year (I did this last year with good directional accuracy but was impacted by some game disqualifications and endowment games!)
This post is the result of this work. I will explain the rankings formula, what the hardest part of getting the rankings accurate and the release of my first power rankings for this year.
Note: All the below is my understanding of the ranking formula, how it’s calculated and what the power rankings look like. These rankings are obviously not official 🙂
What is the Rankings Formula?
The formula is simple in practice but complicated in nature (here is the Power Ranking Formula for Massachusetts). The formula for Girls Basketball is below:
OWN VALUE + OPPONENT VALUE = TEAM’S OVERALL RATING
“Own Value” is based on Margin of Victory (MOV), which is the net score across all your games during that season. For Basketball, the maximum positive and negative value for any game is +10 or -10.
For example, if Team A plays 3 teams.
- Game 1 they win by 2.
- Game 2 they lose by 5.
- Game 3 they win by 15 (would be a +10 to the formula).
They would have a MOV of (2-5+10) = 7 and their “Own Value” rating would be the total net points in their games divided by total number of games. In this case it would be +7 divided by 3 games = 2.333 Own Value.
“Opponent Value” is the tough part. “Opponent Value” is the “Total Overall Rating” across all the teams played during that season. As you might have surmised, this part of the formula changes daily with every new game added into the formula.
This value is impacted by MOV during your opponents games as well strength of schedule of their opponents, all of which is updated daily as games are played. So how do you calculate an ever-changing number that is impacted by each game?
This is done by iterative calculations. Once the scores are put in, the algorithm will continue to calculate “Opponent Value” for each team against the other until a confidence interval is met. Basically, it finds the most correct answer across all teams it can over multiple calculations.
Please note that all updates and overviews for the Power Rankings can be found on the MIAA tournament website.
What Are The Hardest Part of the Rankings?
There are a few things that will always be difficult with the rankings systems including:
- Submitted Games
- The rankings system only works if all teams submit their games and scores. This will always be a challenge to having accurate rankings. All scores should be available in Arbiter Live for MA schools but that’s not always the case.
- One Off Opponents
- For teams that play only one MA school opponent, they are not provided an opponent ranking but the MOV is counted. This adds a secondary calculation that needs to be added. For example, Team 1 plays a tournament in Florida and that Florida team never plays another MA opponent. Team 1 wins by 5 and gets +5 added to their “Own Rating” but the “Opponent Value” is not added because they don’t play another MA team. So this game doesn’t count in their “Opponent Value” calculations.
- Teams with No Games
- Some teams only have a few or no games on their schedules and finding the final schedules for every team can be a bit tough. For these, I’ve added dummy scores that seemed to make sense for games they’ve had but will update as they are submitted.
Finding scores is the hardest part for my rankings but Arbiter should be a good way for the tournament committee to get all the scores in one place. Special thanks to all the local newspapers and school twitter channels for making it easy to locate scores.
If you are interested in following MA athletics profiles on Twitter, I created a Girls HS MA Basketball and a MA HS Athletics Twitter list.
MIAA 2022-2023 Girls Basketball Power Rankings – January 2023
So here we go. Below you’ll find the rankings that I’ve been able to put together for the season so far. A few things of note on the rankings:
- All Scores
- I’ve included a spreadsheet of all the scheduled games and scores that I’ve collected and sources where I captured them. If you notice something wrong or a score I missed, please just add to the comments with a link to where that score is confirmed.
- Our Value and Opponent Value
- I’ve included the information for each team. One thing to note is that for games where they played an Out of State team that only plays one MA opponent I’ve manually updated the MOV while “games” represents the games that count with regards to Opponent Rating.
- Tourney Brackets
- I’ve included all the Rankings by Divisions and also have it set up a bracket for each Division. I used last year’s divisions and teams while removing teams like Austin Prep (who moved to NEPSAC) but if there are errors here feel free to let me know that in the comments as well.
Here is the folder with all the documents. The rankings should become more accurate with more scores from more teams:
Schedule of All Games and Scores
Power Rankings By Team with Current Division Rankings and Brackets
- Note that there are tabs for Rankings and Brackets for each Division
This is a fun project for me. I love data, basketball and analysis and it’s been fun to create these elaborate spreadsheets to see if I can do it. Also, because I’m doing the work already, I wanted to share all the scores I’ve seen and potentially help coaches as they look toward the postseason and see where their teams are.
While these rankings probably aren’t completely accurate to what they will look like at the end of the season, I think they will be directionally correct to have information beforehand. Use it as a fun resource while we await the first true power rankings from the MIAA tournament committee.
I’ll try to update these rankings once or twice a week during the season but assume it will less useful as MIAA releases their version. Enjoy!
Will you do Boys Power rankings?
Unfortunately, the answer is no. It’s a lot of work to follow the scores with the current system. I coach on the girls side so that’s where I’ve focused my attention.
Looks like the rankings will start coming next week though.