CrushWithEyeLiner
I think I read somewhere that last year there were 25,000 students who got 3 A's at A Level. There are around 3000 undergrad places each year at each of Oxford and Cambridge, if I remember rightly. Back in 1993 when I went to Cambridge I think the stats were that 8,000 got 3A's at A level and there were still around 6000 Oxbridge places. So that means there'll be an awful lot of people nowadays with great results who won't be able to get a place.
You asked whether there are a hierarchy of colleges. I think the answer to that is that yes, there are, but that the admissions system is designed to try and make sure that a good candidate doesn't lose out just cos they applied to an oversubscribed college.
The colleges that tend to be oversubscribed are those that are in the centre of the town, old with beautiful architecture, or "famous" colleges and so on. Modern colleges located further out (eg Churchill in Cambridge) or ex women's colleges (eg Girton) tend to be less popular (nb this is no reflection at all on how good they are as colleges, and everyone thinks their own college is the best, wherever they end up). However a "pool" system operates that means that if an oversubscribed college has a really good candidate but just not enough places, then they put them in the "pool" so that all the other colleges who potentially have spare places can interview them. I think both universities publish applications/admissions and pool statistics by college, so applicants can see what happened last year. THe general advice is that you should just apply to the college that you like the best and not play the stats game, because what happened last year is likely not to happen again this year! Having said that, it is safe to say that, say, King's and Trinity at Cambridge are almost 100% certainly going to be more oversubscribed than say Churchill or Girton. Some courses (e.g. medicine) are more popular than others (e.g. theology) though generally I think the number of places available in each subject reflects reasonably well the number of applications).
If you are really really interested (perhaps you have a child of your own who might apply one day) then the Student Room forum threads on Oxbridge are an absolute mine of information.
The universities' own admissions pages are also full of info and they are really pretty transparent about what they are looking for, far more so than in the pre-internet days in 1992 when I applied, when you just plumped for a college, went to the interview and hoped for the best (actually perhaps the old way was much less stressful!).
In terms of what they are looking for, it's a real lively and enquiring mind, a real interest in discussing the subject, and a general "would I like to tutor this person?" test. I don't think having umpteen extra curricular brownie points counts for much - the interview(s) are very much academic ones.
You don't have to be a genius (god knows I wasn't!) but you have to be the sort who likes a good discussion and is used to expressing their ideas about things. Beyond that there's a big dose of luck involved - did you gel with them and they with you etc.
In terms of whether its worth all the bother of applying to Oxbridge, I don't know whether it gives you that great an advantage over any Russell Group university (but I suspect there is some advantage - people are still impressed by the Oxbridge tag, and the the tutorial system, where you spend an hour a week one to one with an expert prof, weakly trying to argue the case for the drivel you wrote in your essay, is certainly character building!). But in terms of the student experience itself, I think there are advantages - especially the tutorial/supervision system, the beautiful and inspiring surroundings, the top-flight facilities, and the fact that you get so well looked after in terms of accommodation/food/financial support for those who need it. There was no "grunginess" in my student experience - three years of beautiful (and cheap!) accommodation in the college and no need to resort to the private sector, a daily cleaner and bedmaker (!), daily food in a medieval dining hall, umpteen book grants, bursaries, travel scholarships. I was so well looked after I couldn't believe it!
HTH
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