<Tr> <Th> TV partner (s) </Th> <Td> NCAA March Madness (CBS / TBS / TNT / TruTV) CBS Sports Network (re-airs) Galavision (Spanish - coverage) </Td> </Tr> <Tr> <Th> Official website </Th> <Td> NCAA.com </Td> </Tr> <P> The NCAA Division I Men's Basketball Tournament, also informally known and branded as NCAA March Madness, is a single - elimination tournament played each spring in the United States, currently featuring 68 college basketball teams from the Division I level of the National Collegiate Athletic Association (NCAA), to determine the national championship . The tournament was created in 1939 by the National Association of Basketball Coaches, and was the idea of The Ohio State University coach Harold Olsen . Played mostly during March, it has become one of the most famous annual sporting events in the United States . </P> <P> The tournament teams include champions from 32 Division I conferences (which receive automatic bids), and 36 teams which are awarded at - large berths . These "at - large" teams are chosen by an NCAA selection committee, then announced in a nationally televised event on the Sunday preceding the "First Four" play - in games, currently held in Dayton, Ohio, and dubbed Selection Sunday . The 68 teams are divided into four regions and organized into a single - elimination "bracket", which pre-determines, when a team wins a game, which team it will face next . Each team is "seeded", or ranked, within its region from 1 to 16 . After the First Four, the tournament occurs during the course of three weekends, at pre-selected neutral sites across the United States . Teams, seeded by rank, proceed through a single - game elimination bracket beginning with a "first four" consisting of 8 low - seeded teams playing in 4 games for a position in the first round the Tuesday and Wednesday before the first round begins, a first round consisting of 64 teams playing in 32 games over the course of a week, the "Sweet Sixteen" and "Elite Eight" rounds the next week and weekend, respectively, and--for the last weekend of the tournament--the "Final Four" round . The Final Four is usually played during the first weekend of April . These four teams, one from each region (East, South, Midwest, and West), compete in a preselected location for the national championship . </P>

How many teams compete in the ncaa tournament