What is the NCAA Evaluation Tool (NET) for women’s basketball?
The NCAA Evaluation Tool (NET) for women’s basketball is the contemporary sorting tool used to measure a team’s quality and help evaluate team resumes for selection and seeding in the NCAA tournament. NET ranking is determined by who you played, where you played, how efficiently you played and the result of the game. The 2023-24 season will be the fourth year that the Division I Women’s Basketball Committee will utilize the NET to assess and rank teams.
What components does the Women’s Basketball NET include?
The women’s basketball NET includes Adjusted Net Efficiency and Team Value Index. The NET rankings DO NOT include any preseason data.
Notes for first NET ranking – early December.
The NET rankings will be provided daily starting in early December, continuing throughout the 2023-24 season. Rankings will be posted here:
The NET is most optimal with a full season worth of data, not in early December. It is released early because of the demand and interest from membership, media and fans. There are certainly outliers involving teams that have played fewer games, but as more data becomes available, with the addition of more games, the more optimal the NET becomes.
During selection weekend, the committee members independently evaluate a vast pool of information. It is these subjective opinions, developed after watching hundreds of games, investing many hours of personal team (or game) observations, review and comparison of objective data, plus discussions with coaches and campus/conference representatives, that dictate how each committee member ultimately votes on the selection of the 36 at-large teams, seeding and bracketing of the teams that make up the 68-team championship bracket each year.
How are the women’s and men’s basketball NET different?
While the systems share high-level goals and individual components, the NET algorithm used in each is different. The machine learning model developed for each sport utilizes only that sport’s data. The women’s model uses only women’s game data, while the men’s model only uses men’s game data. The weights for each are trained using the historical data from the respective sports.
Why doesn’t the NCAA release the formula/algorithm being used for the NET?
The NET ranking is derived from a more complex algorithm rather than a simple formula with relatively straightforward components like RPI (which is 0.25 * [Win Pct] + 0.5 * [Opp Win Pct] + 0.25 * [Opp Opp Win Pct]). Adjusted Net Efficiency and Team Value Index are calculated using machine learning models implemented over many of lines of code, with the calculations adjusting with new results each day in such a way that there is no static “formula” for them.
Will the committee ever adjust the current algorithm?
As they have historically done, the Division I Women’s Basketball Committee each summer before the season starts, conducts an annual assessment of the women’s basketball NET and determines if the NET needs to be adjusted based on new data points in the game.
Will there be a change to the organization of the individual team sheets that are referenced by the Division I Women’s Basketball Committee during selections?
The Division I Women’s Basketball Committee will not be changing the overall look of the team sheets for the 2023-24 season. Team sheets are provided visually as a “category” or “categories” not “quadrants” or “quads.” If there are ever changes to the team sheet organization, information will be communicated publicly once those decisions are reached.
Where should one go for more information on NET?
A variety of Division I Women’s Basketball Championship and NET resources are available at https://www.ncaa.org/sports/2015/9/21/division-i-women-s-basketball.aspx. Members of the Division I Women’s Basketball Committee and/or NCAA staff are always available to answer questions or to provide advice on scheduling and other areas related to the NET. Those interested are invited to reach out to the NCAA women’s basketball staff for more information.
In can be argued that the vast majority of game possessions, even when the score difference is larger, these goals are entirely in line with how coaches are coaching their players. The efficiency component of NET is measuring how well the team is achieving those fundamental goals of basketball, with further adjustments for the opponent and site of each game. While it’s unlikely that teams will employ something unnatural/different from fundamental basketball to "run up the score,” the impact of that possibility is mitigated by calculating things on a per-possession basis throughout the entire course of a season.
What is meant by Team Value Index?
Team Value Index is the results-oriented component of the NET, ranking more highly those teams that played and beat other good teams, factoring in opponent, location of the game and winner.
What does location of the game mean to a team’s NET ranking?
In both Adjusted Net Efficiency and Team Value Index, the same performance against the same opponent will be valued more on the road than at a neutral site, and more at a neutral site than at home. The amount of this location adjustment is based on the data itself, as teams tend to generally perform worse on the road than neutral than at home, so adjusting for that allows for fairer comparisons than just using raw values. With teams playing home games with limited or no fans, the committee and staff is studying the impact that’s having on homecourt advantage compared to a typical year.
What are the differences between NET and the formerly utilized Ratings Percentage Index (RPI)?
The women’s basketball NET is a contemporary sorting tool that more accurately measures the quality of a team determined by who you played, where you played, how efficiently you played and the result of the game.
The RPI was created in 1981 to provide supplemental data for the Division I Men’s Basketball Committee in its evaluation of teams for at-large selection and seeding of the championship bracket. The Division I Women's Basketball Committee began using the RPI in 1984. Simply stated, the RPI provided a ranking of each institution based on their Division I winning percentage and strength of schedule.
RPI consisted of three factors weighted as follows:
- Division I winning percentage -- 25 percent of the RPI
- Opponents’ winning percentage -- 50 percent of the RPI
- Opponents’ opponent winning percentage -- 25 percent of the RPI
How was the current women’s basketball NET algorithm determined?
The Division I Women’s Basketball Committee decided to move from the RPI to the NET for the 2020-21 season after a lengthy evaluation process.
Included was a comprehensive assessment of the strengths and weaknesses of the men’s basketball NET that has been used by the Division I Men’s Basketball Committee as a sorting tool since the 2018-19 season.
Following an analysis of women’s basketball statistical data over a 10-year period by external consultants, the Division I Women’s Basketball Committee concluded that this algorithm was an optimal sorting tool and should be used beginning with the 2020-21 season.
How does the NCAA Division I Women’s Basketball Committee use NET during the selection process, and will the NET ranking be weighed more heavily than the other criteria in the selection process?
The NET is one of many criteria used by the Division I Women’s Basketball Committee in the selection of the 36 at-large teams and seeding of the 68 teams which make up the bracket for the Division I Women’s Basketball Championship.
Criteria used by the Division I Women’s Basketball Committee to evaluate a team includes (alphabetically):
Bad losses Common opponents Competitive in losses Conference record Early performance versus late performance Head-to-head
NET ranking Non-conference record Observable component Overall record Regional rankings Significant wins Strength of schedule
What is meant by Adjusted Net Efficiency?
Adjusted Net Efficiency is a measure of a team’s overall performance during the regular season, determined by the difference between offensive efficiency (points per possession) and defensive efficiency (opponents points per possession). It also accounts for strength of opponents (as measured by their adjusted net efficiency) and location (home/away/neutral) of the games (against Division I opponents only). With teams playing home games with limited or no fans, the committee and staff is studying the impact that’s having on homecourt advantage compared to a typical year.
Does running up the score improve a teams’ NET ranking?
The efficiency component of NET is based on net points per possession, which you can think of maximizing in this way:
Every time down the court on offense, you want to score...the more points the better. Every time down the court on defense, you want to stop the opponent from scoring...the fewer points the better
