FROM THE SECOND week of March, right trough to April, college basketball fever grips the USA as the NCAA men’s and women’s basketball tournaments — otherwise known as March Madness — reach their conclusions.

But just what is it?

Well here’s TheScore.ie‘s simple guide to understanding just what everyone on Twitter is going on about.

Basics

There are 1,100 or so basketball playing colleges and universities in the US and these are divided into three divisions (I, II, and III) based on ability, quality of opponents, number of teams playing other sports, etc. For obvious reasons, Division I teams and tournaments receive the most attention.

Division I is further broken down into 32 conferences and the winners of 31 of those gain an automatic spot in March Madness. The winner of the Ivy League conference also gets an automatic spot but they don’t have a finals tournament to determine a winner, unlike the other conferences.

In 2014, the selection committee picked a total of 68 teams who would enter with the remaining 36 at-large teams (those who didn’t win their conference) being decided at an event known as Selection Sunday last weekend.

These at-large teams are picked based on a number of factors including how many games they’ve won, who they’ve beaten and even the momentum with which they’ve finished their season.

The selection committee also decides the seeding of the tournament from 1 to 68 (1-64 in the women’s tournament). This year Florida, who only lost two games in the regular season, will be the number one overall seed in the men’s bracket.

First four

March Madness gets underway today and tomorrow when eight teams in the men’s tournament —the four lowest-seeded automatic qualifiers and the four lowest-seeded at-large teams—will play off to enter the main draw.

The eight teams in the first round this year include NC State, Iowa and Tennessee.

Regionals

Once the First Four is out of the way, the main men’s bracket will then contain 64 teams, split it into four regions; South, West, Midwest and East. The top ranked team in each region plays the 16th seed, second plays 15th and so on. These games take place between March 20 and 21 this year.

By March 30, the final four teams will be crowned Regional Champions and take part in the National Semi-Finals on April 5 before the National Championship Game on April 7.

Brackets

Where America’s obsession with March Madness really comes to the fore is from filling out brackets. Even the President gets in on the action:

But you don’t have to be the leader of a nation to get involved. Indeed, punters up and down the US will attempt to perfectly predict the result of every game or, at least, as many as they can.

This year, Warren Buffett is offering $1 billion if any one of the up-to-15 million participants taking part can predict a perfect bracket. However, according to Jeff Bergen, a mathematician at DePaul University in Chicago, the odds of doing so are an astronomical 9,223,372,036,854,775,808/1. So no easy task.

So who is likely to win?

While not quite the one-billion dollar question, it seems that oddsmakers are struggling to pick a winner themselves with Florida, Michigan State, Louisville and Arizona all available at between 5/1 and 8/1.

Three-times winners Kansas — available at 10/1 — may represent the best value but Duke and Syracuse (both 18/1) can’t be ignored either. North Dakota State and Harvard at 1000/1 are the rank outsiders.

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