^isn't "most rigorous" when you took the hardest or one of the hardest schedules at your school compared to your classmates. I'm not sure about this, can someone clarify?
You are correct. It's totally upon your counselors discretion. It's more about efficiently taking APs. Certainly not about taking all of them, unless your school only offers like 4, in which case, you'd probably need to take all of them. If your school offers 20, and you took 10, you'd probably still get the most rigorous check mark. But, again, up to the counselor, and they are not given a definition.