Russian system is fundamentally different from the American (or at least it used to be in the USSR): students can choose schools and schools can choose students

Russian system is fundamentally different from the American (or at least it used to be in the USSR): students can choose schools and schools can choose students. For example my school had been admitting everyone for the grades 1-8 but for grades 9-10 there had been a math test. I think about a dozen out of 70 eight graders made to the 9th grade in the same school and the rest had to go to other schools. The class had been replenished with students from elsewhere who also passed the test and went on with 15 hours of math lessons (and 40 hours of homework) per week for the grades 9-10. I don't think something like this could fly in the USA.