March is a special month for NCAA men’s basketball, where 68 teams from all over the U.S. compete for the coveted winning spot in a nationwide competition. The tournament is called March Madness, and it begins this year on Tuesday, March 14 and ends April 3.

Every year, fans of the tournament fill out a bracket predicting the winners and losers of each game. A common way to predict winners is through looking at seed numbers, which rank teams for each region of the U.S. from 1 to 16, which are the South, East, West and Midwest. Villanova is ranked 1 in the East, Kansas is 1 in the Midwest, Gonzaga is 1 in the West, and North Carolina is 1 in the South. While it’s common for the highly ranked seeds to win, upsets also occur and have often drastically changed the results of the entire tournament. And because filling out a perfect bracket is incredibly difficult, the prizes for one are huge: Warren Buffet, the second richest man in the world, hosts a contest where the perfect bracket wins the stunning reward of $1 billion. Yahoo! also has Tourney Pick’Em, where users of the email giant can fill out a bracket and rack up points against other players for a potential prize. Brackets can only be filled until March 16, as that’s when the first big games begin (the First Four [games] occur on March 14 and 15, but are not filled out in the bracket and receive low attention).

The tournament teams include champions from thirty-two Division 1 tournaments and thirty-six teams that are invited to the tournaments via at-large berths. These teams are chosen by a NCAA selection committee, that then proceeds to broadcast the picks on national television. Later, the First Four teams have their play-in games, all currently held in Dayton, OH, and nicknamed “Selection Sunday.” Afterwards, the teams on the bracket play against one another in each region (eight games per region), before only 16 teams are left standing, called the “Sweet Sixteen”. From there, on the last weekend of the tournament, four teams compete (the “Final Four”), until two are left for the finals which determine the national champion.

The tournament has been on TV since 1969. It is currently hosted on CBS, TBS, TNT and truTV. Since 2011, all games are available for nationwide and international viewing, leading to an increase in the tournament’s popularity.

UCLA holds 11 championships and the record for the most, the University of Kentucky (UK) is second, with eight national titles, while the University of North Carolina, Duke University, and Indiana University are tied for third with five national titles. The University of Connecticut is sixth with four national titles. The University of Kansas (KU) and University of Louisville are tied with three championships. Since 1985, when the tournament opened up to 64 teams, Duke has won five championships, Connecticut has four, Kentucky and North Carolina have three, and Kansas, Louisville, Florida, and Villanova have two. UCLA, Indiana, and Michigan State have one.

MMS student Alexis Thomas says she does fill out a March Madness bracket, and predicts Villanova will win the tournament. Classmate Payton O’Neal of the MMS girl’s basketball team says she does also, and thinks UCLA is going to win because, “they are the best team of them all. Plus, they have Angelo Ball on the team and his is range is great, and they have a pretty good defense.”

Of the upsets so far, one of the most major is number one seed Villanova’s loss to Wisconsin, 65-62, in the second round of the competition. With many riding on Villanova progressing further and even winning, this upset definitely ruined some brackets.

Here is a rundown of the current stats: The Sweet Sixteen teams consist of Oregon, Michigan, Gonzaga, West Virginia, Kansas, Purdue, Xavier, Arizona, North Carolina, Butler, South Carolina, Baylor, Kentucky, UCLA, Florida, and Wisconsin, the Final Four teams are Gonzaga, Oregon, North Carolina, and South Carolina, and the final two are North Carolina and Gonzaga. North Carolina was crowned the winner April 3rd, beating Gonzaga 71 to 65.

Scores can be found here.

Updated April 4, 2017, 1:41 p.m.