Brackets have closed, we’ve analyzed the millions of picks, and Butler is the world's most popular upset selection from NCAA.com’s Bracket Challenge. Here are the most popular, in descending order:

Region Seed School Opponent % to upset in R64
East 10 Butler Arkansas 49.02%
Midwest 10 Oklahoma Rhode Island 47.39%
West 10 Providence Texas A&M 40.69%
South 10 Texas Nevada 36.03%
South 11 Loyola (IL) Miami 25.30%
West 11 San Diego State Houston 25.18%
Midwest 11 Syracuse TCU 23.66%
Midwest 12 New Mexico State Clemson 20.27%
East 11 St. Bonaventure Florida 17.68%
West 12 South Dakota State Ohio State 16.41%

No surprise here: the top three selections are all four 10 vs. 7 matchups, followed by three 11 vs. 6 matchups... and then a 12 vs. 5 matchup!

While 12 vs. 5 matchups are the most talked-about upsets in tournament conversations, the teams are still (theoretically) separated by a larger gulf than the 11 vs. 6 matchup, iwhich goes to show how widespread narratives shape decision-making: fans have decided they like 12-seed New Mexico State’s chances against a 5-seed Clemson team, one that endured a brutal ACC schedule, better than 11-seed St. Bonaventure’s against 6-seed Florida. 

The top choice here is Butler, a team whose back-to-back deep tournament runs — and one near-historic title game win — likely remain fresh in the minds of college basketball fans. Less than one percent away from a 50-50 split is pretty impressive for a 10 vs. 7 matchup, even if the 10 vs. 7 matchup is statistically the most even of any double digit-vs.-single digit matchup in the tournament. 

Oklahoma follows in second, close behind the Bulldogs thanks in large part to sensational freshman Trae Young. 

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The Sooners stumbled down the stretch and weren’t even considered a lock to make the tournament, but it seems fans trust Young’s ability to make plays and lift his team in their first-round matchup with No. 7-seed Rhode Island, a team that might be suffering from a lack of instant name recognition despite possessing firepower and pedigree in droves.

Only time will tell whether these pan out, but for now, it looks fans are embracing the upsets as always.

NCAA Digital’s Dan Jepperson and Mike Szahaj contributed to the reporting of this article.

Adam Hermann has written for the Philadelphia Inquirer, the Philadelphia Daily News, Philadelphia magazine, SB Nation, and NBC Sports Philadelphia.

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