The NCAA basketball tournament bracket organizes the teams in the NCAA's postseason tournament so that the match-ups for each round are determined based on which teams win the previous round. Selection committees select 68 men's teams and 64 best women's teams each year to participate each year.
The men's and women's selection committees follow similar procedures, with the main difference being that the men's tournament includes four extra teams. The committee begins by selecting the teams that will be included in the tournament. Each conference's champion makes the tournament automatically, filling 32 spots. The committee then selects the best remaining teams to fill the remaining spots.
Once the field is decided, the committee then ranks all the teams from 1 to 68. Teams are given seeds, with the top four teams receiving a #1 seed, the next four receiving a #2 seed, and so on. The teams are split into four regions of approximately equal strength. The #1 seeds open the tournament by playing the #16 seeds, #2 plays #15, and so on. This rewards the best teams by giving them the easiest match-ups. In a recent addition to the men's tournament, eight of the lowest-seeded teams have to play an opening round game against teams of similar ability to advance into the field of 64. These teams thus would need to win seven times to win the tournament, whereas the other teams need six wins to win the tournament.
The loser of each game is eliminated and the winner goes on to the next round. The seeds before the tournament determine who will play in the next round. For example, the winner of the #1 vs. #16 game will play the winner of the #8 vs. #9 game in that same region. The tournament continues over three weekends and culminates with the Final Four, which consists of the semifinals and the final game of the tournament to determine the national champion.