Complex sentence: Belvidere supposedly competes (if you can even call that competing) in the Northern Illinois Conference (NIC-10) but its more like the NIC-9 cause nobody likes boylan, and is a member of the Illinois High School Association (IHSA).
Split into simpler sentences: Belvidere supposedly competes (if you can even call that competing) in the Northern Illinois Conference (NIC-10), but it's more like the NIC-9 (because nobody likes boylan). It is also a member of the Illinois High School Association (IHSA).