The short version: The 68-team NCAA men's basketball tournament field is determined through a combination of automatic bids and at-large selections, guided by the NET ranking system and bracketing rules.
Key takeaways
- The 2026 tournament field consists of 31 automatic qualifiers and 37 at-large teams selected by a 12-member committee.
- The NET ranking system, which replaced the RPI in 2019, uses Adjusted Net Efficiency to evaluate team performance.
- The committee establishes a true seed order but retains flexibility to adjust seed lines to meet bracketing principles.
- Conflict-of-interest safeguards prevent committee members from participating when 24 or fewer teams remain in the seeding pool if they represent or have family ties to a team in the pool.
How Does a Team Qualify for the Tournament?
For the 2026 NCAA men's basketball tournament, a total of 68 teams will compete in the national championship field. Among these, 31 teams will qualify automatically by winning their respective postseason conference tournaments, earning an automatic bid. The remaining 37 spots in March Madness are filled by at-large selections, which are chosen directly by the selection committee to complete the 68-team field. Tracking 31 NCAA men's basketball conference tournaments, auto bids for 2026 March Madness | NCAA.com
Earning an at-large bid requires an evaluation of a team's performance throughout the season. The selection committee evaluates each team's complete body of work, meaning that having a winning record in conference play does not automatically guarantee a tournament bid. Furthermore, the committee focuses on the current season's performance; past tournament success and program history are not factored into a team's selection. Debunking NCAA tournament myths - NCAA.org - The Official Website of the NCAA
What is the Role of the Selection Committee?
The responsibility of selecting, seeding, and bracketing the tournament field belongs to the NCAA Men's Division I Basketball Committee. This committee consists of 12 members, who are school and conference administrators nominated by their respective conferences. Each member serves a five-year term. What is an at-large bid in March Madness? | NCAA.com
The committee utilizes specific voting procedures. A team can be removed from the field by all but three votes and returned to the under-consideration board. After three tied secret voting rounds, the committee chair breaks the tie. NCAA Division I Men's Basketball Championship Selections - NCAA.org - The Official Website of the NCAA
The final at-large teams fluctuate until the last moment before Selection Sunday. This fluctuation occurs due to conference tournament results and potential "bid stealers"—teams that unexpectedly win their league tournaments and secure an automatic bid, thereby taking away an at-large spot from another bubble team.
How Does the NET Ranking System Work?
To assist in sorting and evaluating teams, the committee relies on the NCAA Evaluation Tool, commonly known as the NET ranking system. The NET ranking system replaced the Rating Percentage Index (RPI) as the primary sorting tool for the selection committee in 2019. Prior to this transition, the Rating Percentage Index served as the primary ranking system from 1981 until 2018, after which the NCAA adopted the NET to provide a more contemporary approach to team evaluation. How do NET rankings work in NCAA tournament selection? - NCAA.org - The Official Website of the NCAA
According to the article "How do NET rankings work in NCAA tournament selection?" on NCAA.org, the NCAA partnered with basketball analytics experts and Google Cloud to create the NET rankings.
The NET ranking system is built on advanced efficiency metrics rather than simple win-loss records. A key component is Adjusted Net Efficiency, which is calculated as the difference between a team's offensive efficiency (points per possession) and defensive efficiency (opponents' points per possession), adjusted for opponent strength and game location. To maintain accuracy, the men's NET ranking uses only men's game data. Crucially, the NET ranking system does not consider raw winning percentage, adjusted winning percentage, or scoring margin. advanced efficiency metrics
The committee uses the NET rankings to categorize games into a quadrant system. The men's basketball quadrant system defines Quadrant 1 games based on the opponent's NET ranking and the game location: home games against teams ranked 1-30, neutral-site games against teams ranked 1-50, and away games against teams ranked 1-75.
How Are Teams Seeded and Placed in the Bracket?
Once the field is selected, the committee establishes a true seed order for all teams. To satisfy all bracketing principles, the committee may move a team up or down one seed line, and in rare cases two seed lines, from its true seed. The overall No. 1 seed is granted the privilege to choose its preferred region and first- and second-round site. Following this, No. 2 seeds are assigned in true-seed order, with the committee retaining the flexibility to move teams slightly to avoid placing the No. 5 seed in the same region as the overall No. 1 seed.
To maintain competitive balance across the bracket, the committee compares the total seed values within each region. The goal of this comparison is to avoid significant imbalance, preferably ensuring that no more than six points separate the lowest and highest total seed values among the four regions.
The committee also follows guidelines to avoid early-round rematches. If possible, the committee avoids nonconference rematches in the First Four and the first round, and tries to avoid them in the second round. However, teams will not be moved off their true-seed line solely to prevent a nonconference rematch. Additionally, first-round and First Four rematches from the previous year's tournament should be avoided when possible.
Specific scheduling constraints also apply to the top seeds in the tournament. If all four No. 1 seeds would normally play at Thursday/Saturday sites, the fourth No. 1 seed is moved to the closest Friday/Sunday site to accommodate First Four winners who must play on Friday.
What Safeguards Protect the Integrity of the Process?
To prevent a conflict of interest, the committee enforces participation rules. When 24 or fewer teams remain in the seeding pool, committee members cannot participate if they represent or have family ties to a team in the pool.
The television networks that broadcast March Madness have no involvement in selecting or bracketing the field; the bracket is built independently by the committee, and the networks simply react to the results once the field is announced.
