Six, since the field expanded to 64 in 1984-85. The last school to accomplish this was North Carolina in 2008-09.
Just under 50% of the 35 preseason No. 1 teams since 1984-85 have advanced to the Final Four. (Note that Gonzaga was the 2020-21 preseason No. 1 team).
Here’s the full breakdown of how the preseason No. 1 teams have performed in the NCAA Tournament:
6 won the national championship (16.6 percent)
8 lost in the national championship (22 percent)
18 reached the Final Four (50 percent)
23 reached at least the Elite Eight (63.9 percent)
28 made it to the Sweet 16 (77.8 percent)
1 lost in the first round