You can move house. You can pay for years of tutoring at up to $100 an hour. But to get a start in year 7 at one of Sydney's best performing high schools, none of that counts if you don't perform well enough in the selective high schools placement test. Figures released by the NSW Department of Education show just how well you need to do.

Two out of three students who competed for a Year 7 place at a selective high school this year missed out, Department of Education figures suggest, with 13,118 applications for 4215 places.

Based on the minimum entry score, James Ruse Agricultural High School was the hardest of all Sydney schools to enter in 2016. The lowest score good enough to get you in was 239 out of 300. There's no direct correlation between entry score and school performance. But the high entry bar for James Ruse is not a surprise because for the past 20 years the school has taken out top spot in the HSC. In 2015 its students scored band six or above in 74 per cent of the exams they sat.

Published minimum entry scores show how well students need to perform on the selective schools test to gain entry. Photo: Jacky Ghossein

Baulkham Hills High School ranked sixth in HSC performance in 2015 but it was the second hardest school to get into, requiring a score of 235 on the selective schools test, followed by North Sydney Boys High (225) and Sydney Girls High.

The Department of Education emphasises that the minimum scores cannot be used to rank schools against each other to gauge performance or even to gauge a school's popularity. They depend on the geographic location of the school and the academic merit of the students who apply.

For the 17 fully selective high schools and 26 high schools with selective classes in NSW, students are placed in rank order and places are filled by moving down the list. The mark of the lowest-scoring student to accept a place in the school is published as the minimum entry score. It varies from school to school and year to year. For example, if offers are declined after the school term ends, it may be necessary to go further down the list than in previous years to fill available places.

The selective school test has four components: reading and writing, mathematics and general ability. A student's primary school's assessment of their performance in English and mathematics is also taken into account.

Merewether High School at Newcastle was the hardest selective school to get into outside the Sydney region in 2016. With a minimum entry score of 182 it was the 22nd hardest school to enter in the state.

The test for entry to Year 7 in 2017 was held in March. Students' families will be notified whether they have been successful in early July. For those who miss out in Year 7, there is another chance to apply for selective school vacancies which may arise in later years and for which schools set their own assessment criteria. Applications for entry to selective high schools in Years 8 to 12 in 2017 open on 27 June.

Among all Year 7 entrants to NSW public schools this year, one in 12 are at selective high schools. For many children the selective high schools test is not an appropriate challenge, and their parents' unreasonable expectations place undue stress on them, according to the chief executive of the Australian Tutoring Association, Mohan Dhall.