Kaka, why should less able kids hold back others? kids should be graded according to their ability. In some subjects they may well be in the top level others they may be in the bottom. Grading kids as you call it or putting them into forms as I do doesn't mean they have to stay in those forms forever, if they show sufficient ability and aptitude in a particular subject there's nothing stopping them moving up to a "clever" form, likewise if they struggle they can get dropped down. That way the school can allocate the best teachers to each form. The kids that struggle are allocated more resources in the form of extra help and tuition than the "flyers" who are in turn allowed to continue their studies without continually being dragged backwards.