A 9 will be level 3. If that is not the case reception teachers are assessing 9s rather over-optimistically and the SATs finds them out. A child you gets 9 in maths/lit is already a couple of years above those with 3 or 4. They won't catch up any day soon. I know the FS is the great leveller and place for dumbing down unfortunately brains will out and no vague criteria can prevent this. The Northampton research is wrong and no doubt was carried out to support their existing theory. Just because it is research doesn't mean its true. You'll be telling me next 7 out of 10 dogs prefer pedigree chum because they carried out research.