The only way that meant the results were based on the students themselves, and therefore fair to them, was the grades estimated by the teachers who know them.
I would disagree that would have been fairer-it would simply have been unfair to a different set of students.
I am totally certain that the 6th form I was at, at the time, would have been announcing "all A/A* results, best year group ever" with any year group they had.
Going by teacher's result, that by statistics were clearly in some cases off means that pupils in the schools where they were better at predicting get relatively unfair grades. What's more that well-deserved grade may be looked down on as "obviously inflated grade", so they'd be doubly disadvantaged, and if they had to fight clearing then there would be fewer spaces, higher grades etc.
Teachers may be able to give predicted grades fairly accurately, but not all of them do. Teachers are human. They make mistakes, they also have their own prejudices. They may try not to let that effect them, but it will effect them-even if it goes the other way and they over predict the ones they don't like because they're trying hard not to.
My mum was a maths teacher. She went on a moderating course on coursework once, which was looking and hoping to improve accuracy for teachers marking. It was around 10 years into GCSE, mostly fairly experienced teachers.
Mum was unusual in that she was the only maths teacher at her school, so was in a group of oddments, whereas all the others were put with their fellow staff members. She said they had some very good discussions. Most of the others were with at least 3-4 others from their school.
They got given some training, then they were given some coursework to grade according and then they reported back.
When they went through the work later dm noticed a couple of interesting things. Bear in mind that there was no knowledge of the pupils, no pressure, simply they were hoping to get it as close to right as possible.
- Teachers from selective schools where they would have got mostly A/Bs (no A*) underestimated greatly lower ability significantly. Ds were dropped to E to G levels, and at least one of the selective schools didn't think they deserved a grade at all. Even some of the low grade Cs they would have placed as E grade or lower.
- The teachers from the large comprehensives put far more emphasis on getting C or G. So they awarded almost no Us or Ds, and not many Es, putting them firmly into C or G category. They also were relatively reluctant to award As, with all but the top being given B/C.
Now this is one example. But it shows how teacher's experience can influence their judgement, even when they are trying to be fair.
Also I think it puts a huge burden on the teachers themselves. Imagine being that teacher who estimates a B knowing they need an A, which you don't think they would have got? You and only you were responsible for them not getting in. I suspect teachers would be getting hate mail and being vilified (again) in the press.
And if we end up in the same situation again then the teachers' grades would be even more over estimated to try and beat the other overestimates.
I'm not saying that the current way was fair, but I think teacher's grades would be less fair. It would probably be good for my dd who's expecting her GCSE results, so I'm not arguing against it for that reason. If they gave her her predicted grades from January then she'll be a very happy (and rather lucky) girl on Thursday. But I still don't think it is a fair way of doing it.