It’s that wonderful time of year again that is enthusiastically referred to as March Madness. With the play-in games starting Wednesday the madness is underway.

So how do the teams make it to the big dance? Out of the 68 teams that make the tournament 32 teams got there by winning their conference championship. The rest were awarded at-large berths by the selection committee. That same committee then ranks the teams 1-16 based on their record, strength of schedule, and Ratings Percentage Index (RPI).

And there’s always an upset. According to the New York Post in 2012 the no. 2 ranked Missouri Tigers were contenders to win it all but got beat by the no.15 ranked Norfolk St. Spartans.

As if the games aren’t exciting enough there’s the thrill of the bracket challenges. There are numerous challenges available including for the first time ever the billion dollar bracket challenge. According to the Washington Post Quicken Loans will pay out $1 billion to whoever picks a perfect bracket, but the odds of doing that are 9.2 quintillion-to-1 or 1 in 128 billion if you are knowledgeable about the teams. Easy enough right?