While it is technically possible to make a perfect March Madness bracket, the odds are overwhelmingly against it–no one in the history of the NCAA tournament has ever made a verifiably perfect bracket to date.
The big dance has had 68 teams competing in its field since 2011. Eight of those teams compete in the “First Four," or play-in games that take place before the first round of the tournament. Most bracket pools disregard these games and only count games starting with the official first round of March Madness, when 64 teams tip off.
Beginning with the first round through the championship, there are 63 games in a standard NCAA tournament bracket.
Assuming that the odds of picking each game correctly are an even 50-50–like a coin flip–the number of possible bracket outcomes is 9,223,372,036,854,775,808, per most mathematicians, which make the odds of picking a perfect bracket and getting all 63 games correct are a staggering one in 9.2 quintillion. One quintillion is one billion billions.
Back in 2015, Duke math professor Jonathan Mattingly tried to calculate the odds of picking a perfect bracket for the average basketball fan. His strategy attempted to take things like prior knowledge of teams and the preceding regular season, tournament history, and an understanding of the sport itself into account. It also considered odds like the fact that a 16-seed has only beaten a one-seed one time in history (135 out of 136 one-seeds have won their first round game).
According to Mattingly, an averagely-aware fan has a far better chance of achieving bracket perfection than the 1 in 9.2 quintillion odds suggest. Mattingly's numbers say that the odds of picking all the games correctly is actually one in 2.4 trillion.DePaul mathematician Jay Bergen used a different formula to calculate the odds of picking a perfect bracket to be one in 128 billion.
Despite differing calculations about what the actual odds are to create a perfect bracket, one thing is clear: it's nearly impossible.