SAVANNAH, Ga. () — The college basketball season is winding down, which means March Madness is upon us. The annual men’s and women’s National Collegiate Athletic Association tournaments are among the most closely watched sporting events in the U.S.

No matter how much you know about college basketball — if you’re looking to follow the fun, make your own bracket, or even just trying to understand what all the fuss is about — here are some things to know.

What is March Madness?

It’s the basketball world’s term to reference the upsets, chaos, remarkable plays and historic moments that are sure to happen in postseason tournaments.

It all starts with teams playing a tournament against the other schools in their conference, which is the division that a school competes in during the regular season. One slip up there and a team could find itself “on the bubble,” or at risk of missing the ensuing NCAA Tournament. And it ends with the ultimate prize: a school being crowned the champion.

The teams are selected, seeded and placed in a bracket by an NCAA committee made up of 12 members. The brackets are broken up into four regions: Midwest, East, South and West.

The goal of the committee is to create a bracket that’s equally competitive in each region.

Why is it called March Madness?

The term “March Madness” was first used by Henry V. Porter, a high school official in Illinois, in 1939. But the term wasn’t officially used in reference to college basketball until 1982, when CBS broadcaster Brent Musburger used it during that year’s coverage.

Why do I hear so much about March Madness brackets?

Every year, millions of people fill out their own brackets in hopes of correctly guessing who will win each round. A huge reason why March Madness is so popular is its unpredictability. Lower-seeded teams regularly beat the higher-seeded ones, throwing brackets and predictions completely out of the window.

How is the bracket created?

Thirty-one of the 68 teams automatically qualify to play in the NCAA Tournament because they won their respective conference tournaments. The remaining 37 teams are chosen by that 12-person committee mentioned earlier.

Next, the committee will seed all of the teams. It determines seeding by wins, losses, strength of schedule and other metrics.

The teams are seeded 1-16 within each of the four regions. The top-seeded team will play the bottom-seeded team, and so on.

What if I fill out a perfect bracket?

Well, you’d be the first. The odds of doing so are astronomical. The closest anyone has ever gotten on the men’s side was an Ohio man in 2019 who predicted the entire tournament into the Sweet 16.

If you do happen to make a perfect bracket, there could be more in it for you than just bragging rights. Perfect bracket pickers have been offered as much as $1 billion. That’s the figure Warren Buffett offered to his Berkshire Hathaway employees in 2014 if any of them achieved such a lofty goal.