This is OP. I didn’t realize it worked that way. Two slots for Campbell! Good to know.

Your answer is here:
https://www.apsva.us/school-options/middle-school-choices/middle-school-countywide/
Its by your elementary, each gets an allocation. See the table on the link.

I just read the other thread about the HB lottery. I don’t know yet if my daughter will want to apply to HB but what is the deal with the allocations? And is it by your zoned elementary school? DD goes to Campbell, which is another option school.