Do believe the hype: NFL draft is the craziest show in town

For the true devotee of the National Football League, the high spot of the year is not the Super Bowl, or some bonecrushing hit or miraculous touchdown pass. In fact it's not during the season at all, and it takes place nowhere near a stadium. The best moment comes tonight, in Radio City Music Hall in midtown Manhattan – the start of the 2012 NFL player draft, when the League's 32 teams choose their future.

For months everyone's been on the case. Managers, coaches and scouts have been sizing up the talent available, calculating which of the college stars available best fits their needs. There are seven rounds to the NFL draft, but the climax comes at the beginning in the very first of them, when the cream of the crop is selected live on prime-time national TV.

The master of ceremonies will be Roger Goodell, the NFL's Commissioner. On stage, he announces the top picks. One by one, a procession of young men will emerge from the wings, brandishing the jersey of his new team. Later they will sign contracts worth tens of millions of dollars and – if all goes according to plan – change the fortunes of a franchise. And, as befits the hype that envelops America's most supersized sport, the top overall picks are superstars even before they have played a single second in the NFL.

The most prized assets, not surprisingly, are quarterbacks. This year boasts a couple of exceptional ones: Andrew Luck, latterly of Stanford University and now destined for the Indianapolis Colts, and Robert Griffin III, of Baylor University in Texas, who will be picked second overall by the Washington Redskins. The next three picks – to judge from the antepost betting – will send the offensive tackle Matt Kalil to the Minnesota Vikings, Trent Richardson, a running back, to the Cleveland Browns and the corner back Morris Claiborne to the Tampa Bay Buccaneers. After that, however, it is anyone's guess.

Every major league sport in the US consists of a group of franchises operating basically as a cartel, exempt from the country's otherwise stringent anti-trust laws. There is no promotion or relegation; the only changes occur when new teams are admitted or when a franchise moves to another city for financial reasons.

The US may be the proud champion of raw capitalism where business is concerned. But it's the opposite when it comes to professional sport, a cosy place where a team can lose for decades and suffer nothing more than the abuse of its fans. In this stagnant set-up, drafts are essential to maintain competitiveness.

They vary in style. The NFL's is the flashiest and also the simplest, a natural extension of college football which provides virtually the entire talent pool of the league. The NBA basketball draft, consisting of just two rounds and spiced by foreign megastars like Yao Ming and Dirk Nowitzki, may well be the most fun. Baseball's, predictably, is the most complicated, running to 40 or more rounds.

But the principle in every draft is the same. The worse the team, the higher the pick. Thus in the NFL, the franchise with the poorest record the previous season (in 2011 the Colts) gets first choice, while the Super Bowl winner goes last. Typically a player who is selected signs a contract binding him to a franchise for a minimum four years. In this way, it is argued, the best players are spread around, making the leagues genuinely competitive.

And up to a point, the theory works. Since the Premier League opened in England in 1992, four clubs have won the title. By contrast 13 teams have won the Super Bowl and 11 the World Series over the same period. Even the NBA has had eight champions.

The draft of course is not a perfect guide. Some top picks have proved colossal flops; others have been eclipsed by players chosen far lower. Tom Brady for instance, who has led the New England Patriots to three Super Bowls, only went in the sixth round of the 2000 draft.

For the moment though, only hope reigns. In Indianapolis, Luck is being hailed as the natural successor to Peyton Manning, while in Washington the impending arrival of Griffin is a bigger deal than Barack Obama. Obama after all is merely trying to rescue the country. Griffin has a much tougher task: to restore the city's beloved football team, who have not been to the Super Bowl in two decades.

To secure him, the Redskins have paid a double price. Not only will Griffin command a contract worth a king's ransom but also, just to get him, the team agreed to give their first and second-round selections this year, and their first-round picks in 2013 and 2014, to the St Louis Rams. It's a monster gamble – but that's what makes the draft such fun.