That's an interesting comment Capers, are you suggesting you have a number you can allow when hearing appeals?
No. A panel must consider in each case whether the parents' reasons for wanting a place outweigh the prejudice to the school.
Assuming they are minded to uphold a number of appeals, they then have to consider whether the school could cope with that number of (potentially) successful appeals.
If they believe that the school could not cope, they have to compare cases, decide which are the strongest, and at what point the prejudice to the school becomes too great. (Each time they admit an extra pupil, of course, the prejudice to the school has become greater.)
In theory (and I stress 'in theory') they could reach this point after allowing just one appeal.