We literally explained this one page ago. Go have a look if you really want to know.
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EDIT: Okay, I have anything to say about ranked; when you get in, open your god damn mouth and speak up where you want to go.
I just had to dodge a game because both me and someone else picked mid, after I had asked "Shall I mid then?" without anyone speaking up. I mean, my worst role (ADC) was covered so I could have gone anywhere, yet people don't speak at all.
It's just... you can avoid so much trouble if you just speak up. Don't just sit there with your thumb up your knockhole.
Luckily I have not been put in a tier yet, so I don't get an LP penalty.