Unless you have a shit ton of mastery points on shaco, don't play him in ranked.

Completely useless champion 90% of the time. I'm going to start dodging every match with a shaco, because 90% of them either do nothing and are useless, or soak up kills and do absolutely nothing.

A good shaco can carry, sure. but don't just pick shaco while having no experience and expect to be able to do anything. Otherwise you may as well just be troll picking.