I think someone mentioned Brampton Manor which is a selective academy in East London, sending lots of kids to Oxbridge. The thing is in the Sixth Form they take 400, all need an average points score of at least 6,5 but if they want to study eg Computer Science for A level, they are not allowed to unless they have a 9 in Maths and Physics. Chem and Bio etc at least an 8, FM a 9, the subjects combinations are all quite specific.
Whilst some schools like this may be comprehensive at 11 plus, they are not at 16 plus, far from it (and the existing cohort who do not make the cut, cannot stay on). Often a lot of these kinds of London supposed comprehensives cream off the top performing students locally from all comprehensives and even grammars. Then the press goes on and on about successful non selective state schools? When some of them chuck out their existing cohort? Not saying that grammars do not do exactly the same, it is what it is.
All these classifications of comp vs grammar etc what do they actually mean when loads of Sixth Forms are actually selective? If Oxbridge were to start limiting North London grammar students, for example, plenty would just find another selective Sixth Form that would welcome them with open arms. This is also why some private school kids do go to state sixth form, don’t they? So these stats mean what exactly? Especially for London, aren’t they entirely pointless if there is a public transport system and selective state sixth forms available for those who have top grades and want to go there?
A lot of parents encourage their DC to move at Sixth Form, also as a form of extra prep for uni life and having to settle in somewhere new, mature, make new friends etc, focus on a place that offers exact subject combination in a successful manner?