 Though each conference receives only one automatic bid, the selection committee may select any number of at-large teams from each conference.The at-large teams generally come from college basketball's top conferences, including the ACC, The American, A-10, Big 12, Big East, Big Ten, Mountain West, Pac-12, and SEC.Many of these at-large teams, however, are "on the bubble", meaning that their chances of gaining a tournament berth are borderline, and they will not know if they have gained entry until the Selection Sunday bracket announcements.