March Madness: With even Barack Obama involved, why are college sports so popular in the United States?

The NCAA college basketball tournament starts today and the President of the United States has picked his 'bracket' - so what is it all about?

Seton Hall celebrate winning the Big East tournament (GETTY IMAGES)

Ascending the escalators inside the Manhattan venue the crowd is in a frenzy, chanting and goading their way to their seats. Madison Square Garden, arguably the most iconic arena in the world, is packed. But this mob is not here to see a world renowned artist or even the New York Knicks who call it home - instead they are here to see the semi-finals of a regional college basketball tournament.

Villanova are playing Providence, followed by Xavier against Seton Hall to determine the finalists of the Big East conference. Despite these names probably being unfamiliar to audiences this side of the Atlantic, the pumped crowd at Madison Square Garden cares. In fact all America cares because college sports, and in this case basketball, are treated very differently to the UK.

Today is when March Madness gets properly under way, a 68-team national college basketball tournament officially known as the NCAA Division I Tournament. Every match is shown on live television, and this year can be seen on BT Sport ESPN in the UK. It is hectic - the knock-out tournament over in just three weeks. It is also unpredictable, with the bigger colleges regularly being upset by the 'Cinderellas', the unfancied smaller colleges.

It is a tournament that enthrals the nation, watched by huge audiences both in person and on television.

"It's a time when people who never watch college basketball, they're going to watch it," explains ESPN's recruiting insider for college basketball, Jeff Borzello.

But why does a sport essentially played by amateurs garner such interest?

"The most similar thing would be the FA Cup," says Borzello. "Everyone roots for the smaller teams and so that's what makes it great is when a small school, with perhaps 3,000 students, goes up against a school with 40,000 students and wins. That's what everyone hopes for.

"The best team doesn't always win and that's appealing for people."

The Duke Blue Devils celebrate after defeating the Wisconsin Badgers during the NCAA Men's Final last year (GETTY IMAGES)

The greatest appeal of the tournament is 'picking your bracket'. As soon as the teams participating are confirmed on 'Selection Sunday' (32 qualify through their regional conferences and divisions, such as Seton Hall who won the Big East, and 36 are selected by a panel based on form, star players and other criteria) they are put into a 'bracket' based on seeding which maps their path to the final. Millions then try to predict how the tournament will pan out. Among them this year is the President of the United States, Barack Obama, whose bracket was released to the public earlier this week and shows he thinks the Kansas Jayhawks will ultimately triumph.

"Even if you don't care about college basketball you probably still fill out your bracket," says Borzello.

Such is the unpredictability of the tournament the odds of getting it completely correct are tiny. This year billionaire Warren Buffett has offered $1m-a-year for life to anyone who predicts a bracket with 100 per cent accuracy (something incredibly unlikely to actually happen) and also works for his company Berkshire Hathaway. But with offices and friends playing against each other, bragging rights are up for grabs in a similar way to fantasy football played in the UK.

Such is the interest that a whole cottage industry has been created known as 'bracketology'. Joe Lunardi, who works for ESPN as a bracketologist, began predicting brackets 25 years ago and has an excellent record of picking the teams that will take part in the tournament. He explains how it works.

"Literally everyone plays a bracket game," he tells the Independent. "People want to get a head start on assessing the teams and working out who might get through, which is why there is the fascination with me. I give them what they want ahead of time.

"The last three or four years has been insane with people and cameras and microphones following me around like I'm Moses coming down from the mountain with the 10 commandments. Believe me, this is neither that important, nor am I all that."

Selection Sunday took place last weekend in which Lunardi made three incorrect calls, something that has happened just once before - he is usually just a team out and sometimes calls it 100 per cent right.

I'm Moses coming down from the mountain with the 10 commandments

&#13; <p>Bracketologist Joe Lunardi</p>&#13;

Lunardi says that the levels of interest in college sports owes much to most people having an affinity with a particular university.

"What's unique to college basketball is everyone has a team, everybody has a school because almost everybody went to school. Either it's your school or it's your father's school or it's your sister's school or it's where great uncle Harry went or something."

He also believes that top-level leagues such as the NBA fail to serve the entire population.

"We have 50 states here in the US. Probably less than half of them have top level professional sports. So if you live in Alabama you don't have a team in the NBA or the NFL or MLB (baseball). So your team is (University of Alabama teams) the Crimson Tide. I think it (the popularity of college sports) is because of the size of the country."

A view of the NRG Stadium in Houston, where the 'Final Four' will meet in this year's tournament (GETTY IMAGES)

The 'madness' element of the tournament comes from the frenetic scheduling. Over the next four days the teams will be whittled down from 64 to the 'Sweet 16'.

"There are single moments of frenzy," says Lunardi. "The tournament starts at noon on a Thursday and obviously people are working. In America, a lot of people get the sniffles on that day, particularly if your team happens to be playing at say 2.30pm."

Borzello adds: "That first Thursday it's just non-stop from noon until midnight. The smaller schools get to play the bigger schools and it just drags any sports fan into college basketball."

Another four days of action from March 24-27 will see the sides reduced to the 'Final Four'. Those semi-finals are traditionally played at a football stadium rather than an arena, meaning an incredibly large crowd turn up to watch the stars of tomorrow. The final this year takes place at the 72,000 capacity NRG Stadium in Houston on April 4. If the crowd is anything like that seen for the qualifying tournament at Madison Square Garden, the atmosphere will certainly be madness.

BT Sport is the home of the NBA and College Basketball in the UK, showing up to seven live NBA games and up to 14 live College matches per week throughout the season. From March 15th, BT Sport will show ‘March Madness’ - a knockout tournament featuring the top 68 college basketball teams in the US – exclusively live on BT Sport ESPN.