Every year, the British media will bang out the same predictable stories about the Oxbridge entry process. In December they’ll write about crazy interview techniques; in August, they’ll debate the existence of systemic bias towards posh people. These stories have been written since time immemorial, as regular a feature of the British newspaper diet as Diana conspiracy theories and Winterval.

You don't get these kind of stories about Exeter or LSE, do you? The obsession with Oxbridge is entirely unique. It'd be nice to think this scrutiny reflects the fact Oxford and Cambridge graduates are more likely to end up with their hands on the levers of power in this country, but I suspect the truth is simpler: the media is disproportionately fascinated by Oxbridge entry largely because it’s disproportionately populated by Oxbridge graduates.

I am, I’m afraid, one of them, so what follows is probably just as self-indulgent as everything I was just complaining about. But I’m going to say it anyway because, in all the acres of newsprint about the class system and questions like "why is a banana", there's one substantial point that no one ever seems to mention: quite how much of the entry process is down to luck.

This is a strong claim, so will take some unpacking, but the reasons why mostly come down to two things. One is the collegiate system; the other is the interview process.

Consider. When you apply to Oxbridge, you generally apply to take a specific course at a specific college. Some courses receive lots and lots of applications; others, relatively few. Now, you can make an open application, and let a computer choose your college for you instead, which evens out the odds slightly; and anyway, the universities maintain it’s not possible to use this information to game the system.

But none of this changes the fact that some courses are simply more competitive than others: the playing field is not entirely level. If you’re good, but your chosen college doesn’t have a place for you, they’ll stick you in the “pool”, and if you’re lucky you might be plucked out to plug a gap at another college. Then again, if the right person doesn’t look at your paperwork, you might not. Bad luck.

The other reason Oxbridge entry can be ever so slightly arbitrary is that admissions are largely based on interview – and, as anyone who’s ever been interviewed for anything can attest, interviews are an art, not a science. Great candidates will be petrified and under-perform; lesser ones may have a natural confidence that sees them through. And anyway, how you do will depend to an extent on the rapport you have with your interviewer. One candidate may click with the tutor and shine; another doesn’t and won’t. If they’d applied to the college next door, it might well have been the other way around.

The result of all this is that those who are accepted will, to some extent, be those for whom the fates aligned. A few kids are so bright they’re all but bound to get in; a few won’t be academically strong enough, and won’t.

But in between, there's a vast swathe of candidates that could go either way. Maybe they performed well on the day. Maybe they were up against relatively weak competition. Maybe they got an interviewer who just happened to like them, and decided that this was a person they'd like to have around for the next three years. Any of these things might well have gone against them.

None of this is “unfair”, exactly. Oxbridge does remain disproportionately populated by the bourgeois and well-heeled, but whether this is the fault of the admissions process or some external factor is very far from clear. And, despite the horror stories, relatively few admissions tutors go out of their way to terrify nerve-wracked 17 year olds. The most detailed look at the application process from the inside is probably this excellent piece from the Guardian, which shows the admissions tutors taking contextual information like social background and school quality into account, and all but agonising over which candidates to take.

But it also shows them making subjective judgements about how to balance grades, confidence and background, and taking split second decisions about marginal candidates that it’s easy to imagine going the other way. And these, remember, are decisions that are going to have a massive impact on the opportunities open to those kids when they graduate. An Oxbridge degree isn’t an automatic ticket to fame and fortune (believe me, I know). But it still opens doors that many other degrees, with similar grade requirements and at excellent universities, just don’t.

Maybe, under the circumstances, it shouldn’t.