Does anyone know how exactly people are picked for teams in ranked?

In silver 4 now. I worked up form b5. Getting up to promos isn't that bad. Decent people and decent teams. EVERY promo I go through I have to go though I have to do it 3-4 times. Just now losing my 3rd promo to s3 I looked over my team mates stats. Half or more are b4-b5. What's the point of the rank system to get the better players up and keep the bad players down if they are getting thrown together. Does anyone know how people are picked or what is going on. Most of the people in bronze have no map awareness or basic team picking to meld together well. Ranting now just a question of anyone knew.

Off topic but does anyone know whats going on with 'no internet' error that's back? had a game 5 of the 10 people had it. Hadnt happened in about 3 days no it back full force.