This is my first season of participating in ranked play and I was wondering how the rating system works. Is it based off individual performance or simply your win/loss record? Because I've played 4 ranked matches and even though I had one easy victory, the other three I had a terrible feeder teammate each time that blew the game for my team. So will the system look at my good score, or will it look at my losses and forever keep me in low elo hell?

It takes into account your hidden rating, your team's collective hidden rating, and the other team's collective hidden rating and awards or deducts LP based on that. Your individual performance is rewarded only if your team wins.