As I understand it, the rank you get at the end of a game is based on the average for that champion in that position e.g. if I decided to play jinx jungle for whatever reason, I'd be ranked against other jinx jungles and not against all the jinx ADCs out there.
My question is, what does someone get ranked against if they don't play a conventional role? I ask because I just had a game where two people insisted they were premade top, and in response I played solo Poppy bot and got an A+ (much to my frustration). So who was I ranked against? ADC poppy or support Poppy? Or Would I be ranked against top Poppy because I was solo?