You want to know why there aren't more black students at Oxford? Watch South Park.

In the South Park episode Eek! A penis!, Eric Cartman – an obese, astonishingly foul-mouthed eight-year-old – heads to an inner-city school and teaches black and Latino students how to succeed like white people – by cheating. Cartman gives the class a pep talk:

The reason that you think you can't get into college is because you haven't been taught how to cheat properly. How do you think white people get ahead? Because they cheat all the time!

And it's true – particularly when it comes to university entry. During the recent furore over black students (or "the black student", if you're David Cameron) at Oxford, the university gave out a very thorough press release that broke down the application success rates for ethnic minorities. It made one thing strikingly clear.

The reason black applicants struggle to gain access to Oxford is that they are applying for the subjects that allow them the smallest chance of success. Take a look at these two figures, taken from the press release:

28.8 per cent of all black applicants for 2009 entry applied for medicine, compared to just 7 per cent of all white applicants.
10.4 per cent of all black applicants for 2009 entry applied for economics and management, compared to just 3.6 per cent of all white applicants.

Medicine and economics + management are the two most competitive subjects at Oxford: 12.6 per cent of applications to study medicine are successful, while a mere 7.6 per cent of management applicants get in. Black applicants struggle to get into Oxford largely because they are applying to study the most competitive subjects.

Meanwhile, the subjects that have extremely high application success rates, such as theology, classics and archaeology and anthropology, are stuffed with the pasty-faced products of Britain's public schools. Forty per cent of theology and classics applications are successful, while just under a third of archaeology and anthropology candidates get a place.

There is a game to be played if students want to avoid becoming another Laura Spence, who applied for the most competitive subject (medicine) at one of the most competitive colleges (Magdalen) and, lo and behold, failed to get a place. Black students should instead follow Nick Clegg's example.

Clegg studied archaeology and anthropology at Cambridge, despite being far from the archetypal archaeology student. Indeed, young Clegg spent his teenage years burning down greenhouses in Germany, working as a ski instructor and – according to that interview with Piers Morgan – frantically fornicating with anything female-shaped.

The typical archaeology student does none of these things. So why did Clegg study A&A as an undergrad and not, say, politics, which he did at postgrad and then chose as a career? Because it was easier to get into Cambridge that way. A&A has half as many applications as politics. He knew it, his private school knew it and so Clegg played the game. While black students claw and fight for a place on the most competitive subjects, the Cleggs of the world stroll into Oxbridge through the back door.

This isn't cheating, it's savvy. Until secondary schools wise up and start giving pupils better advice about their applications to the top universities, highly qualified candidates from unprivileged backgrounds will continue to struggle to gain access to the upper echelons of Britain's higher education system – and the headlines that have hit Oxford over the past few weeks will not go away. Britain's secondary schools need a few more Eric Cartmans.