there's really no point in going to a selective high school from years 7-10 because, well lets face it years 7-10 count for absolutely nothing. but in year 11 & 12, i think you appreciate being in an environment with other people who also expect to do really well in the hsc a lot more. also, because there's a lot more competition, you have a much better idea of what you're up against, as opposed to normal schools where teachers give you full marks just for being able to string a sentence together (ok calm down , i know im exaggerating but im just trying to illustrate my point) having said that though, if you really want to do well in the hsc, it shouldn't matter which school you go to.