Question about ranked 3.0

I don't understand how this new ranked system is supposed to work. In a ranked match I was playing recently, there was a former champ on the enemy team. I had a gold on my team. We got absolutely destroyed 4-0. So my question is, if there is a gold on my team and I'm playing against someone who hit champ in the past, how do I lose more than average for this game? I lost 26. For a loss, I usually lose around 25.