Acceleration only works if you have a teacher to actually teach you. At my school, accelerated students had to teach the whole course by themselves up until yr 10, where they were then put in a year 11 class, which then meant they still had to teach half the course by themselves anyway because year 11s get more periods dedicated to the subjects.
If anything, acceleration only made some people dumber (ie, me). Why? Because you get lazy after teaching yourself in one subject for 4 years. Plus, acceleration works its best if you know you're going to do exceptionately well in that course and if you're willing to put some extra stress on your back at a younger age.
