URF champ select

I keep getting the same rotation of champs over... and over... and over... and over... and over... and over... and over... I literally only have a handful of champions, and I am getting the same 5 over and over. I understand the term "random", but this is starting to come to a point where correlation=causation. Is there some algorithm that selects certain champs based on scenarios? Really frustrating playing the same 5 champs.