“I have sympathy with the view that a lottery system can feel arbitrary, random and hard to explain to children in years five and six who don’t know what’s going to happen and don’t know which children in their class they’re going to be going on to secondary school with,”Yes Ed, the whole point of a lottery is that it is arbitrary and random. That is why it is a lottery. If it's hard to explain to chidren in years 5 and 6 that just shows how crap our schools really are.
Anyway there is a reason why there are waiting lists for the best state schools- because the supply is essentially fixed. If good schools could expand or spread out and poor ones close then demand could equal supply.