I met a former pupil recently and the conversation soon turned to the day 25 years ago when he got his A-level results, of which we both had a clear memory.

He had just missed his grade offer from Manchester University of BBB and we telephoned universities that we knew would take an applicant with BBC. I found him a place at Swansea, but in the meantime he had had a call at home with an offer from Queen Mary London. We got his friend, who had missed out at Manchester with the same grades, into the vacant place at Swansea. Clearing is a wonderful thing.

Results day was a big day every year during my time as a headteacher. Family holidays were timed to ensure that I could be in school; results analysis was done as soon as the school received the grades; the important part was to be available for the students whose futures depended on their grades and, possibly, on the advice and support that they received from school. Immediately after getting a set of disappointing results is hardly the best time to make life-changing decisions but, under the pressure of the university entrance system, that is exactly what some 18-year-olds have to do - and they need support from experienced adults whom they know and trust.

For heads and teachers, there are the highs of sharing individual success with the students and the lows of disappointment and upset at failure. Results day is nerve-wracking for students who have taken their A levels, AS-levels and GCSEs, and for their parents, but it is a tough day for teachers, and especially for school leaders too.

For headteachers, in particular, life has got a lot tougher in the past 10 years, as football manager syndrome has grown - but without the big payoffs and the prospect of a quick move to another post on the managerial merry-go-round - and government power brokers have created a situation in which a head is only as good as his or her last set of exam results.

‘Not fair on students or teachers’

This year will be particularly difficult, with a crisis of confidence in the grades awarded after the government has destabilised the system with so many changes. When TES reports that only 6 per cent of the teaching profession has complete confidence in the grades, we know that reform has been too much, too quickly. Significantly, TES also reports that headteachers are less confident than teachers about both GCSE and A-level grades. And it is the heads whose jobs will be at risk.

In 13 subjects, new AS qualifications are being taken and there is understandable uncertainty when changes of this magnitude are introduced. Ofqual’s associate director, Cath Jadhav, has explained in a blog that, as students tend to do less well in the first year of a new qualification, Ofqual uses its ‘comparable outcomes’ approach to ensure that students are not disadvantaged by being the first cohort to sit the new ASs. With AS separate from A-level, fewer students are taking the AS and these may be of different ability to last year’s AS candidates, so Ofqual tries to accommodate this in its approach to grading. Managing uncertainty is part of its role in maintaining standards from year to year.   

There was volatility in the IGCSE English language results last year, with a return to normal being seen this year in the recently reported results. One secondary school reported its C-grade pass rate up by 29 percentage points on last year.

All schools have good year groups and weaker ones, when it is more of a struggle to get the pupils through the examination. Teachers know that they have to work harder some years than others to gain the same results. But they should be able to rely on the stability of the examination grades and, in a system changing as fast as that in this country, the awarding bodies will do their best, but what teachers previously regarded as rock-like year-on-year grade levels have become part of the shifting sands of educational reform.

That cannot be good for the system and it means that results day will be an even more tense occasion than usual in 2016.

John Dunford is chair of Whole Education, a former secondary head, general secretary of the Association of School and College Leaders and national pupil premium champion. He tweets as @johndunford

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