Every spring, millions of fans turn their attention to one of the most exciting events in sports: March Madness. Officially known as the NCAA Division 1 Men’s Basketball Tournament, the competition features 68 colligate teams competing in a single-elimination bracket for the national championship.

Teams qualify through two main methods: automatic bids and at-large selections. According to the National Collegiate Athletic Association (NCAA), automatic bids are awarded to conference champions, while at-large teams are chosen by a selection committee based on performance, strength of schedule, and overall record.

Teams are seeded 1 to 16 in each region based on how strong they are compared to other teams. Once selected, they are matched up where higher-seeded teams face lower-seeded teams in the early rounds.

The unpredictability of the tournament is what makes it so popular. Upsets, when lower-seeded teams defeat higher-seeded ones- are common and often create memorable moments.

According to ESPN, bracket participation has become a major part of the experience, with millions of fans attempting to predict game outcomes each year. No one has ever made a perfectly correct March Madness bracket.

From the First Four, where eight of the lowest-seeded teams compete to fill the final spots in the main bracket, to the Final Four, where the final four teams remaining in the tournament compete, March Madness continues to showcase the excitement and intensity of college basketball.