What are the Odds of Filling out a Perfect NCAA Tournament Bracket?

What are the Odds of Filling out a Perfect NCAA Tournament Bracket? article feature image

Brian Spurlock-USA TODAY Sports

It’s bracket season, baby! For many fans, a perfect bracket is the crown jewel of March Madness. But perfection is hard. There has never been a bracket filled out electronically on one of the major sites (ESPN, Yahoo, CBS, etc.) that made it through the title game clean.

According to the NCAA, the longest a bracket has remained perfect is 39 games. This streak occurred last season with a bracket remaining unblemished until the final matchup (Purdue vs. Iowa State) on the third full night of action.


What are the odds of perfection? If you pretend every game is a coin flip (50/50 probability), the chance of a perfect bracket is 1 in 9.2 quintillion. However, the chances are better than that if you consider a 16-seed has never beaten a 1-seed. By adjusting probability based on seeding, Jonathan Mattingly, a professor at Duke, calculated the odds to be 1 in 128 billion. Better, but still next to impossible.

How likely is a perfect bracket using the Bracket Simulator? We simulated each game by round 10,000 times assuming our projected favorite won every matchup. For example, Virginia defeats the University of Maryland, Baltimore County, then Creighton, Kentucky and on until the Cavaliers win the championship over Villanova in the title game.


Here are the approximate odds that the The Action Network’s simulated bracket is perfect after each round:

After the first round, not including the play-in games, there is approximately a 1 in 20,000 chance that we get all 32 games correct. After the first weekend of the tournament we are approaching 20,000,000-1 against, and the odds escalate quickly after that.

If the team at The Action Network could fill out 49,855,667,842 brackets, there is a chance we would get one perfect. While we get started on those brackets, here is a prop bet for a perfect bracket to be submitted on ESPN.

Will there be a perfect bracket on ESPN

  • Yes +5000
  • No -12500

The odds suggest the probability that there won’t be a perfect bracket is 99.2%. Since the actual odds are basically 100%, anyone with an extra $12,500 burning a hole in their pocket should place this bet to win $100.

Photo via Brian Spurlock-USA TODAY Sports