What are the most likely upsets in the first round of March Madness?

Throughout the first round of March Madness, everyone is always looking to see which high-seeded team will fall first. In history, there have been 333 instances of a higher seed upsetting a lower seed, which by definition is an upset.

Some upsets occur more often than not, with the 8/9 matchup being the most common upset, with 83 occasions. Obviously, the 1/16 upset is the least likely upset, with just two instances in history.

With upsets happening annually in the first round, we’re taking a look at how many upsets have happened for each first-round matchup and the matchups for each scenario in the 2026 bracket.

March Madness Upset History

1 vs. 16

With just two upsets in history for no. 16 seeds, it’s hard to imagine any of the top seeds in this year's bracket falling. Especially with all four of them being the top ranked teams in the KenPom rankings as well. This year’s matchups consist of Duke vs. Siena, Arizona vs. Long Island, Michigan vs. Howard, and Florida vs. Lehigh/Prairie View A&M.

In 2018, UMBC became the first-ever 16-seed to beat a 1-seed in Virginia. Five years later, in 2023, Fairleigh Dickinson took down Purdue.

2 vs. 15

In another lopsided historical matchup, a No. 2-seeded team has only lost to a No. 15-seeded team 11 times. It has happened three times since 2021, however, it hasn’t happened in the previous two tournaments.

Of UConn, Purdue, Houston, and Iowa State, who make the 2-seeded teams, Purdue has the most losses this season of the bunch, with eight, while UConn is the lowest-ranked 2-seed on KenPom.

3 vs. 14

A 3-seed has fallen to a 14-seed 23 times all-time in March Madness. Looking at this year’s 3-seeds in Illinois, Virginia, Michigan State, and Gonzaga, this could be the most prone bunch to upset yet.

Michigan State and Illinois have each been upset as a 3-seed in the past. Also, Virginia has been upset three times since 2018 as a top-4 seed in the tournament.

2024 was the last time a 3-seed went down in the first round when Jack Gohlke and the Oakland Golden Grizzlies took down Kentucky.

4 vs. 13

This is a more frequent March Madness upset than some might think, with a 13-seed toppling a 4-seed 33 times, with seven of them coming in the last seven tournaments.

This year’s No. 4 seeds are made up of Kansas, Nebraska, Arkansas, and Alabama. Of the bunch, Nebraska has never won a March Madness game in the history of its program.

5 vs. 12

Getting into the bread and butter of March Madness upsets, a 12-seed has 57 all-time wins over a 5-seed. Across every NCAA Tournament in history, only six times has there been a tournament in which at least one 12-seed has not advanced (1988, 2000, 2007, 2015, 2018, 2023).

The 5/12 matchups this season are St. John’s vs. Northern Iowa, Wisconsin vs. High Point, Texas Tech vs. Akron, and Vanderbilt vs. McNeese.

There are two potential upsets brewing amongst these four matchups in Akron over Texas Tech, given the Red Raiders' injuries and Akron's momentum as they ride a 10-game win streak. Also, High Point is a matchup nightmare for Wisconsin with their ability to shoot from deep and Wisconsin’s lack of defense against three-point shots.

6 vs. 11

Tied for the most upsets in March Madness history, an 11-seed has taken down a 6-seed 62 times. That gap has narrowed significantly since 2014, with No. 6 seeds holding a slight 52.3% (23-21) advantage over 11-seeds.

BYU, Louisville, Tennessee, and North Carolina are this year's No. 6 seeds. Louisville and North Carolina are the most vulnerable of the four, being that each of their top scorers are ruled out for their games.

BYU could be considered a liability with their inconsistent play to finish the year, having lost five of their last nine games. As for Tennessee, they haven’t lost in the first round in their last five tournament appearances.

More: Dangerous 12-seed features 6th-year senior that could be 2026's March Madness hero

7 vs. 10

Another more common upset as 10-seeds have won 39% of matchups against a 7-seeded team all time, accounting for 62 wins.

The matchups between the two seeds in this year’s tournament are Kentucky vs. Santa Clara, Saint Mary’s vs. Texas A&M, Miami vs. Missouri, and UCLA vs. UCF.

8 vs. 9

Of every upset scenario here, the 8/9 game is the only one all-time where the higher seed has the advantage, with 9-seeds winning 51.9% of the time with an 83-77 edge.

Ohio State vs. TCU, Villanova vs. Utah State, Clemson vs. Iowa, and Georgia vs. Saint Louis are this year’s matchups.

More college basketball news:

• Darryn Peterson situation not alarming to NBA teams, ESPN insider says
• Will Wade expresses displeasure about NC State in the First Four
• Why Mikel Brown Jr. isn't playing for Louisville vs. USF with injury news
• March Madness upset predictions for 2026 NCAA men’s basketball bracket
• Where Arkansas Darius Acuff Jr. ranks among John Calipari's best NBA guards