Almost certainly this will be because Eton has chosen to take the more challenging IGCSE exams rather than the conventional GCSE. Lots of Private Sector schools are doing this but unfortunately QCA and DfES do not recognise the exam when compiling league tables.
My daughters schools KEHS has done the same and have suddenly dropped from No1 in the league tables to close to the bottom.
The following is a quote from the Headmistress from the school web site:-
Just a reminder of something I mentioned at the end of the summer term- because last year’s U5th entered IGCSE mathematics, an exciting and challenging alternative to GCSE, the school will appear on the DfES ‘league tables’ published Thursday 11th January as having 0% of girls with 5 GCSEs A to C grades, including Maths and English.
We shall therefore have gone from top of the league to bottom.
In fact all 78 girls achieved A to C in IGCSE maths, and 67 gained A or A* grades.
I would say “League tables? – What nonsense!” were it not for the fact that at A level we are the top independent school in the country on point score per candidate.
Click here for League Tables for A level
Click here for League Tables for GCSE. We have included IGCSE results for KEHS