The single-elimination tournament is held in the Spring every year in the United States and features 68 of the best college basketball teams in the country. The teams are comprised of conference champions and at-large selections. The tournament is hosted by the NCAA and serves as the National semi-final and final for basketball.
The tournament, organized by the National Collegiate Athletic Association (NCAA), was first developed by the National Association of Basketball Coaches in 1939 and was the brainchild of Kansas coach Phog Allen. The NCAA would take over the tournament the following season.
Known as March Madness or the Big Dance, the tournament takes place over three weeks at sites across the USA, with the semifinals (aka The Final Four) being one of the nation's most important sporting events.
The phrase "March Madness" was coined by Henry V. Porter in 1939 to describe an Illinois high school basketball tourney. Brent Musburger first used it during NCAA coverage in 1982 causing a legal battle almost as insane as the playoffs. But everyone finally worked things out and the madness was official. There isn't a good record of who first called the playoffs "The Big Dance", but it does describe the action.
The tournament bracket has included conference tournament champions from each Division I conference (31), which receive automatic bids; the Ivy League Champions also gets an automatic bid but is chosen. The remaining slots are at-large berths, with teams chosen by an NCAA selection committee. The selection process and tournament seedings are based on several factors, including team rankings, win-loss records and RPI data. The lowest-seeded teams compete in the "opening round games" to determine which will join the other 60 teams in the first round of the tournament.