How do NET rankings work in NCAA tournament selection?

Breaking down the NCAA's key ranking system and how it shapes March Madness selections

Posted on 3/3/25 12:00 PM

March Madness is one of the most exhilarating times of the year for sports fans. As Selection Sunday approaches, teams, analysts and fans closely monitor the NCAA Evaluation Tool — aka the NET —rankings to determine which teams are likely to receive an invitation to the NCAA Division I Men's and Women's Basketball Championships.

But how exactly do the NET rankings influence the NCAA tournament selection process? Let's break it down.

What are NET rankings?

Introduced in the2018-19 season for men's basketballand the2020-21 season for women's basketball, NET rankings replaced the Rating Percentage Index — known as the RPI — as theNCAA Division I Men's and Women's Basketball Committees' primary sorting tool for evaluating teams.

The NET is designed to be optimal in March, not in early December. It is first released in December each year due to demand from the NCAA membership, media and fans. There are going to be more outliers early in the season because of the limited data available, more so than what you might see in other metrics that use preseason data as a starting point for those rankings. The NET does not use any data from prior seasons or any preseason rankings or inputs.

Two key components of NET rankings

  1. Team Value Index—A results-based measure that rewards teams for beating quality opponents, with extra weight given to road and neutral-site wins.
  2. Adjusted Net Efficiency—The difference between a team'soffensive efficiency (points per possession)anddefensive efficiency (opponents' points per possession), adjusted for opponent strength and game location.

Differences between men's and women's NET rankings

While both Division I men's and women's basketball use NET rankings, there are some key differences in how they are calculated and applied:

1. Distinct algorithms

Each sport has a unique machine-learning model trained exclusively on its own historical data. Themen's NET ranking uses only men's game data, and thewomen's NET ranking uses only women's game datato ensure accuracy.

2. Quadrant differences

The definitions of Quadrant 1, 2, 3 and 4 wins vary between men's and women's basketball. The home-away-neutral quadrant NET rank ranges are unique to each respective sport and were determined using historical home/away/neutral site game results. Quadrant ranges for both men's and women's basketball reflect expected winning percentage versus a given opponent rank (in NET) with respect to game location, across all games. Expected winning percentage comes from regression models on past game results, predicting a team's chance of winning based on its NET, the opponent's NET and the location of the game. Expected winning percentage for each game is calculated from a "top team" perspective to reflect how hard each game is to win for NCAA tournament-worthy teams.

Does running up the score improve a team's NET ranking?

A common misconception is that teams can boost their NET rankings by running up the score. However,NET does not factor in margin of victoryin a way that encourages this.

How efficiency affects NET

NET rankings focus onper-possession efficiency, meaning that teams benefit most from:

Since these arefundamental goals of basketball, most coaches and teams naturally play in a way that aligns with NET's efficiency model.

How location impacts NET rankings

Wins and losses are weighted differently depending onwhere the game is played:

Since teams tend to perform worse away from their home gym, the NET ranking adjusts forlocation-based difficultyto create fairer comparisons. The quality of the opponent matters significantly, as well. Winning on the road against the 25th-ranked team in the NET is valued more than winning on the road versus the 75th-ranked team.

What data is not included in NET rankings?

Certain traditional metrics arenot factored into NET rankings, including:

How are NET rankings used in NCAA tournament selections?

NET rankings play a role in helping the Men's and Women's Basketball Committees evaluate teams, but they arenot the sole factorin determining who makes the tournament. Instead, the committees use the NET as a guide to sort teams into four quadrants, which categorize wins and losses based on quality:

Men's basketball quadrant system (vs. team rankings in NET)

Women's basketball quadrant system (vs. team rankings in NET)

A team's record in Quadrant 1 games is one of the strongest indicators of tournament worthiness. The committee looks favorably on teams that secure multiple Quadrant 1 wins while mostly avoiding Quadrant 3 and 4 losses.

Does the NET ranking alone determine a team's fate?

No. While NET rankings provide a data-driven framework, the basketball committees also consider additional metrics and evaluation tools.

Committee members have a wide range of observation, consultation and data resources available to them throughout the season and during selection week.These resources provide the foundation for a thorough and educated process that is reinforced by the committee members' discussion and deliberation.Among the resources available to the committee are an extensive season-long evaluation of teams through watching games, conference monitoring calls, National Association of Basketball Coaches/Women's Basketball Coaches Association regional advisory rankings, complete box scores and results, head-to-head results, results versus common opponents,imbalanced conference schedules and results, overall and nonconference strength of schedule, the quality of wins and losses, road record, player and coach availability, and various computer metrics. The 12 committee members use these various resources to form their own opinions, resulting in the committee's consensus position on teams' selection and seeding.

Men's basketball additional considerations:

Women's basketball selection criteria (in alphabetical order):

Why did the NCAA move from RPI to NET?

TheRating Percentage Indexwas the primary ranking system from 1981 until 2018 but was replaced by the NET to provide a more comprehensive and contemporary approach toward evaluating teams. The RPI included three components:

To create the NET rankings, the NCAA partnered with basketball analytics experts and Google Cloud.

Final thoughts

NET rankings have improved how teams are evaluated for the NCAA tournament, providing the committeesa more comprehensive tool. However,tournament selection is still a nuanced processin which the committee considers multiple factors beyond NET rankings.

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