Under old (current) system, the benchmark was at least 6A*s for Oxford for humanities, rising to ten or more for Medicine (extenuating circumstances excepted).
But now how is a pupil to know what is good or not? Ten 9s? Five 9s? What if, say, Westminster pupils all get ten 9s but someone from a comprehensive gets 8s (when they would previously both have got all/mostly A*s)?
Is 9 even achievable? Obviously in Maths it is easily done for a very able person, but what about English/History? How is one to know if a 7 is decent or a disaster?