Only nine Division I men's basketball teams have finished their season with a perfect record since the start of the NCAA tournament in 1939 - seven of which won the NCAA title. Here a breakdown.

1955-56 San Francisco 29-0

San Francisco was the powerhouse of the period with Bill Russell and Hal Perry leading the way. The NCAA final 83-71 victory over Iowa clinched the Dons' second straight crown and ran their unbeaten streak to 55 games. All-American guard K.C. Jones was ineligible for the NCAA tournament but San Francisco continued its run - which started in the regular season where it had not won by less than seven points.

1956-57 North Carolina 32-0

The North Carolina Tar Heels crowned off their undefeated campaign by holding Kansas' Wilt Chamberlain to just 13 points in a 54-53 triple-overtime thriller. Joe Quigg made two free throws with six seconds left in the third extra session to give UNC the title. Head coach Frank McGuire's Tar Heels had beaten Michigan State a night earlier in triple-overtime as well. All-American Lennie Rosenbluth, North Carolina's leading scorer during the season at 28 ppg, fouled out with 1:45 left in regulation.