I slightly got off point in comparing NLCS (private) and Henrietta B (state grammar) but good point re 2020 results for both being skewed due to pandemic.
I can do a google search limiting dates to 2019 and seem to get this for NLCS
NLCS is celebrating its best ever A* performance at GCSE level. This is the first year when the majority of grades awarded at NLCS were using the new 9-1 scale.
NLCS students achieved an outstanding 66% grade 9 and 89% grade 9 or 8 and we are incredibly proud of them!
Only 800 girls in the whole of England managed to get straight grade 9s, and 4% of them are our students.
"29 North Londoners achieved Grade 9 in 10 or more subjects, and 76 girls were awarded A* or equivalent in 10 or more subjects.
Students achieved amazing results in English and Maths. 97% achieved grade 9 and 99% grade 8 or 9 in English literature, and 100% secured grade 8 or 9 in English Language.
A high proportion of students choose Maths at NLCS, and a fantastic 93% students achieved grade 8 or 9 and 68% grade 9."
And A levels doing the same 2019 search only
"Almost uniquely for a London school, we offer a diverse curriculum which means that girls can study the International Baccalaureate or take a combination of 3 or 4 A Level or Pre-U subjects.
This summer we were delighted to celebrate another superb set of International Baccalaureate Diploma results in July with and average points score of 41 (placing us once again as one of the top schools in the world offering this challenging curriculum). Three of our students gained the maximum score of 45 points this year, something usually only achieved by around 200 students out of 160,000 candidates across the globe.
Our combined A level, Pre-U and IB results are also excellent – this year 36% of students received the equivalent of A, with 76% at AA and 92% at A*B level.
NLCS students are now preparing to take up offers at the most prestigious universities world-wide with offers from the UK, EU and the USA.
Overall, twenty six students will take up their Oxbridge and Ivy League places, marking us out as one of the most successful schools in the country this year."
B - state GCSE 2019
GCSE results 2019: Henrietta Barnett headteacher pays tribute to ‘fabulous’ year group as 95pc get a grade 7 or higher
person
Harry Taylor
Published: 3:53 PM August 22, 2019 Updated: 2:01 PM October 14, 2020
"Henrietta Barnett year 11 pupils have got an “excellent” set of results despite the new format of GCSE’s, the school’s head Del Cooke has said.
Nearly 80 per cent of GCSE exams were given grades 8 and 9, and 95pc were at grade 7 or above.
In total 16 pupils got ten grade 9s or more."
A levels 2019
"The head of Henrietta Barnett school in Hampstead Garden Suburb has paid tribute to its cohort of students, on a day where 70 per cent of A-level grades achieved by pupils were A* or A grades.
26 pupils got into Oxbridge universities, while nearly three times that number got A* or A grades in at least three subjects.
The all-girls school, which was founded in 1911, had 92pc of grades which were A* to B."
It is too complicated to compare. Basically if you have academic selection and girls only whether paying or not paying you tend to get high grades.
Oxbridge will always miss some good people (loads probably) but just needs to be careful not to let in people who aren't up to it as it might lower the standard for others if there is catching up to be done in year 1. If that is not happening then that's fine. If it is happening and catching up does not occur over 3 years employers will start t move away to places where the people they want are. I do not think there is much risk of that.