Normals

Because normals mmr (the rating that matches people of similar rating/skill level) is different from that of ranked. So while they may be platinum in ranked they are not that high in normals (they could also be playing with friends of a lower level which can pull them down to a lower mmr). While the system is typically pretty good about balancing teams and the such there are times when things like this happen.

well that stuff needs to be fix.im trying to get better and enough champs to start rank.this is bullshit that i have to waste 20 minutes of my life to get shit on.that aint fun to play.theirs a reason why people play dota over LoL