Unlike the previous prediction of 1-2 students getting straight 9s, this one is based on an analysis of 2016 exam data by Cambridge Assessment.
For students taking at least 8 subjects, they reckon between 200 and 900 will get straight 9s, out of about half a million students.
About 2000 got straight A*s in 2016.
www.tes.com/news/very-few-will-get-GCSE-clean-sweep