My friends and I once argued about the primary reason top schools "produce" overachieving students. She thought that at least a part of it is from better staff and student to teacher ratio, whereas I argued that most of it is a self fulfilling prophecy. Families that cares most about education will sacrifice the most (time, money, opportunity cost) to get kids into elite schools, and those kids will work harder and devote more resources to test-prep.

This article states that failure-rate went from 8-9% to 25%, but I'm curious how that compares to the regional average. If say 35%-40% of 9th graders failed in surrounding regions, it would be an argument to keep the lottery based system.