Doesn't it depend on what you mean by catch up? I'm not familiar with Levels and SATs scores. But isn't the point that some schools don't seem to have a strategy for getting all pupils to reach the top level (Level 5) in 3Rs?
Surely some schools start with children who can't even speak English. Presumably those children are harder to teach than the ones who can already read, write to-some-extent and multiply by the time they start Reception.
I also notice that some initially well performing children leave primary school performing poorly. (I'm pretty sure this is a parental-inclusion problem) ie it's the parents and the school's fault not the child's.
Schools performances