I got silvers they got nothing but gold

So why do I have a...

S1, S2, LV30 (unranked), myself (G4), and a G5 vs S4, G4, G4, G5, G5

I mean a S4? um, okay maybe got good MMR. Why do I have 2 silvers, and an unranked!? How does the MMR of an unranked player equal low gold? I mean I guess it does...