Since the NCAA Men’s Basketball Tournament began in 1939, there have been 81 national champions crowned. Actually, the official count would be 80 seeing as how Louisville had its 2013 title stripped after committing a series of rules violations, which ultimately cost Rick Pitino his job. Nevertheless, 80 teams have won an NCAA title. But there are a select few that stand out.

Let’s face it, it’s hard to win a national championship and even harder to remain undefeated for an entire season. Teams have off nights. It just happens. So when a team enters the NCAA Tournament with a flawless record, it’s quite impressive. But a bad draw or an off night in the tourney can erase a phenomenal regular season in an instant. Take Larry Bird‘s Indiana State Sycamores in 1979. They rolled through the regular season and had a 33-0 record when they faced Magic Johnson and Michigan State in the national title game. And they missed out on history when the Spartans emerged victorious, 75-64.

The same can be said for UNLV in 1991. The defending national champions came to the Final Four with a 34-0 record but lost to Duke in the national semis. Undefeated Wichita State lost to Kentucky in the second round of the NCAA Tournament in 2014. The following year, the tables turned on Kentucky when the 38-0 Wildcats lost a Final Four matchup to Wisconsin.

In total, just seven teams have gone undefeated and won an NCAA title and four of those came from one school as part of the most dominant run in history.

San Francisco (1956)

Before Bill Russell led the Boston Celtics to 11 NBA titles, he was the most dominant player in college basketball at the University of San Francisco. In the 1954-1955 season, Russell led the Dons to the NCAA championship with a near-perfect season of 28-1. The following year, San Francisco achieved the first tournament-era undefeated season, defeating Iowa in the national title game to complete a 29-0 season. Russell averaged 20.6 points and 21 rebounds per game that season and finished his collegiate career with a 46-game winning streak.

North Carolina (1957)

With Russell gone to the NBA, the North Carolina Tar Heels took over as the best team in college basketball in 1956-1957. Led by co-ACC Players of the Year Lennie Rosenbluth and Pete Brennan, UNC won their first NCAA title with a thrilling triple-overtime victory over Wilt Chamberlain and the Kansas Jayhawks, 54-53. The Tar Heels finished the 1956-1957 season with a 32-0 record.

UCLA (1964, 1967, 1972, 1973)

In 1963-1964, UCLA began the most dominant era in college basketball history, winning the first of 10 NCAA national titles in 12 years under legendary coach John Wooden. Gail Goodrich led the way in ’64, averaging 21.5 points as the Bruins beat Duke in the championship game to complete a 30-0 season.

In 1966-1967, a young man named Lew Alcindor, who would later become Kareem Abdul-Jabbar, joined the Bruins and had one of the most dominating seasons in college basketball history, averaging 29 points and 15.5 rebounds per game. 1967 marked the first of seven consecutive titles for UCLA but was amazingly Alcindor’s only undefeated season. The Bruins beat Dayton in the title game to cap a 30-0 campaign.

From 1971-1973, UCLA went on a crazy run. With Bill Walton leading the way, the Bruins didn’t lose a single game, winning both the 1972 and 1973 national titles. UCLA’s 88-game winning streak is still the longest in men’s college basketball history.

Indiana (1976)

The last undefeated team to win a national championship was Bob Knight’s 1975-1976 Indiana Hoosiers. Behind the combination of AP Player of the Year Scott May and Kent Benson, the Hoosiers went wire-to-wire as the No. 1 team in the country. After beating UCLA in the national semis, Indiana knocked off fellow Big 10 member Michigan, 86-68, to win the school’s third national title, completing a 32-0 season.