Strategies that can upset "articulate parents" are needed to make school admissions fairer, a watchdog says.
Dr Hunter says the system needs "checks and balances"
Philip Hunter, the chief schools adjudicator, said sought-after schools could "cream off" children in neighbouring areas.
It meant some schools are left with too many children from deprived homes.
His annual report proposed no national solution: it said authorities must use "highly contentious" methods, such as admissions lotteries.
In some areas, such lotteries - or ballots - have been adopted. In Brighton, some parents objected, unsuccessfully.
The adjudicator who heard their complaint ruled that the new system would likely result in "a greater degree of justice".
Dr Hunter said in his report that solutions would vary across the country.
"Some schools are situated in areas with a high proportion of privileged families," he said.
"These schools may produce very good results and become popular.
"They can 'cream off' children from neighbouring areas, sometimes leaving schools in those areas with a disproportionate number of children from deprived families.
"Clearly, the best way to enhance parental choice is to improve unpopular schools," he said.
"In many areas, however, other strategies must also be employed.
"They are likely to be highly contentious, many of them deeply unpopular with groups of articulate parents."
'Checks and balances'
Dr Hunter said: "There isn't some kind of national answer.
"Lotteries have their uses. They are usually used as a tie-breaker. They are useful in this respect.
"The solutions are going to be different in different areas."
Dr Hunter said the "market" in education meant the best secondary schools could fill their places with pupils from more comfortable backgrounds.
"They do find ways of selecting the easier-to-teach children," he said.
"It is not deliberate, it just happens. Therefore, we have got to have checks and balances in the system."
It was the duty of local admissions forums to review things annually and tackle unfairness, he said.
Dr Hunter's report said the new, tougher admissions code introduced by the government had yet to bed down fully.