* Inevitably a few pupils in a year group will fall ill and miss some of their subject examinations;
* One or two may have transferred late into the school from different educational backgrounds, perhaps from abroad, and not have taken the full range of subjects;
* One or two pupils may be quite properly out of age in the year group - their results don't count; one or two may have suffered from adolescent or family trauma.
Good grammar schools go to considerable lengths to support such youngsters and still produce 95-100 per cent of pupils gaining five or more A-C, along with an average number per pupil in excess of eight or nine subjects.
This is an important endorsement of the grammar school pupils' year on year performance at this stage.
Simon Langton Grammar School for Boys