President Obama’s chalk-heavy bracket aside, there are likely to be a number of upsets in this year’s NCAA tournament. But will those improbable victories rise to the level of the greatest NCAA upsets of all-time? Time will tell, but in the meantime, here are some of the greatest giant-killing performances in March Madness history.

[NCAA tournament cheat sheet]

Villanova over Georgetown in the 1985 title game

The Wildcats never got higher than 14th in the Associated Press poll during the 1984-85 season, went 5-6 to close the regular season and lost by 15 points to St. John’s in the Big East tournament semifinals. But then eighth-seeded Villanova caught fire in the NCAA tournament, toppling top-seeded Michigan in the round of 32 and North Carolina and Memphis, both seeded second, in the Elite Eight and Final Four, respectively, to set up a title-game matchup with Georgetown, which had defeated the Wildcats twice in the regular season. Villanova needed to play a perfect game to have any chance against the mighty Hoyas and it nearly did, shooting an absurd 78.6 percent from the field despite relying heavily on just five players (the Wildcats’ reserves played just nine of 200 minutes in the game). In the end, Villanova pulled off a thoroughly improbable 66-64 win.

[Fancy Stats: Most likely first-round upsets in 2015]

N.C. State over Houston in 1983 title game

Two years before Villanova’s upset of Georgetown, the Wolfpack followed a similar path. N.C. State dropped out of the national rankings in early January after rising only to 15th. But the Wolfpack caught fire a little earlier than Villanova, winning the ACC title and earning a No. 6 seed in the NCAA tournament. Five wins later, including one in which it trailed Pepperdine by eight with a minute left and another over top-seeded Virginia in the Elite Eight, N.C. State found itself matched up with Akeem Olajuwon, Clyde Drexler and 31-2 Houston, the nation’s No. 1 team when the tournament began. The Wolfpack held the Cougars to just 38.2 percent shooting and limited Drexler to just four points. And in the end, after Lorenzo Charles dropped Dereck Whittenburg’s miss into the bucket as time expired, Coach Jim Valvano was looking for someone to hug.

[Four low seeds that could make deep NCAA tournament runs in 2015]

Texas Western over Kentucky in the 1966 national title game

The Miners became the first college team to win the national title with an all-black starting lineup, beating Adoph Rupp’s mighty Kentucky team, 72-65, a victory so important that they made a movie out of it.

[Why this year’s South Region is ripe for upsets.]

Duke over UNLV in the 1991 Final Four

In 1990, UNLV delivered one of the most dominant performances in national title game history, throttling Duke in a 30-point victory. But one year later in the Final Four, the Blue Devils got their revenge, ending the Runnin’ Rebels 45-game winning streak with a 79-77 victory.

Richmond over Syracuse in 1991 first round

No. 15 seeds have defeated No. 2 seeds in the first round seven times now, but the Spiders were first with a 73-69 win over an Orangemen squad that spent nearly the entire season in the top 10. The win probably should not have been a surprise: Under Coach Dick Tarrant, Richmond made the Sweet 16 as a No. 13 seed in 1988 and upset Charles Barkley and Auburn as a No. 12 seed in 1984.

Florida Gulf Coast over Georgetown in 2013 first round

The Hoyas make their second appearance on this list — it would have been three times had Princeton pulled off the 16-1 upset in 1989 — with a loss to a school that most people did not know even existed until the night of March 22, 2013. Of all the 15-2 upsets in NCAA tournament history, this one was the most surprising if only because of the way the Eagles completely dominated the Hoyas, dunking on them with undeniable flair all night long in a 78-68 win that wasn’t nearly that close.

Santa Clara over Arizona in the 1993 first round

Led by a skinny Canadian kid named Steve Nash, the 15th-seeded Broncos stunned the second-seeded Wildcats, 64-61. Arizona was a 19.5-point favorite but ended up losing in the biggest point-spread upset in NCAA tournament history.

LSU over Kentucky in 1986 Elite Eight

Only three double-digit seeds have advanced to the Final Four, and none had a stranger season than the 11th-seeded Tigers in 1986. LSU lost three centers during the season — one, the then-heralded Tito Horford, more or less vanished — and battled a chicken pox outbreak. But after finishing on an 8-11 skid, the Tigers beat No. 3 Memphis in the second round, No. 2 Georgia Tech in the Sweet 16 and the top-seeded Wildcats in the region final thanks in part to a confounding defense called “The Freak.” It would be 20 years before another double-digit seed — George Mason — replicated the Final Four feat.

Princeton over UCLA in 1996 first round

Seven years after the Tigers almost pulled off the impossible against Georgetown, they got the job done as a No. 15 seed against the defending national champion Bruins, backdooring their way to a 43-41 victory. And oh yeah, it was one of the first time Gus Johnson went nuts on the mic for CBS.