frogs is spot on about the 'something special', the glint in the eye that marks out the very best at oxbridge interviews - it's hard to describe, but it's very obvious when you see it. And the point about the best candidates being those who aren't thrown by being told they're wrong, but able to incorporate that information and continue to think creatively is also absolutely right. Best to remember that grades are now effectively irrelevant unless of course you're predicted less than straight As or have ropey GCSEs without a good reason - you've got to have the As, but apart from passing that 'bar' they don't make any further difference for Oxbridge because all the candidates have them/are predicted them, with very few exceptions, so the issue for the tutors is to distinguish between them. Don't be deluded into believing - whatever the school says - that extra-curricular things make any difference. By and large, they don't, though schools get v. irritated if you say this at open days/schools visits! UCAS statement/schools references are significant up to the point at which candidates are selected for interview, but not much after that (except of course as useful contextual information, or fodder for the gentle ice-breaking opening question). Exams or tests set by Oxford and Cambridge - either taken there when up for interview or at school - are a major factor though, and increasingly common, and of course the work you send up matters too. There is a proportion - perhaps 10 or 20% - of candidates who are so obviously great at interview that there's no question about admitting them, and if your son is in that category he's likely to get in wherever he's at school; similarly there's a (larger) proportion who make the interview cut but clearly aren't, after interview, in the running, and there's not a lot to be done about that either. The bit that matters, to be honest, is the middle range - where tutors have 3 spaces left, say, and 6 candidates, all very good in some ways, with some weaknesses, all of whom would be fine. This I suspect is where the best schools do their stuff, stretching and stimulating their students as much as possible so that they are on as good form as they can be. I'm not sure if that helps much, but it might help you to think about why your son's current school has good results, but doesn't do so well at Oxbridge, and what you might be able to do to supplement it if he doesn't move. But it must come from him - the students who are being propelled by their parents' desire for the place, not their own, are also pretty obvious once you talk to them at interview.