I won 7 out of 10 games...

I won 1, lost 1, won 2, lost 1, won 2, lost 1, won 2. This doesnt seem possible.. XD i deserve silver 5 atleast.

Your initial placement is based on your MMR at the start of the season.

If you have never played ranked games before, then you begin with approximately Silver3/4 MMR.

If you have played ranked before, then your initial MMR will be somewhere between Silver 3/4 and your MMR at the end of last season. Silver 5 is lower than Silver 3/4, so you started lower than you were previously.

The order of the wins is a factor too. If two players began at the same MMR and both won 6/10 games, the player who won their first six games will likely place higher than the player who won their last six games.

Riot did a soft reset meaning the system counted you as less than what you were last season. Since you were s5 you were pretty much bronze already therefore placed in bronze.

i lost 7, won 3, and i somehow made silver 5 last season

A lot of ppl complaining about being placed in lower ranks here on BR too. Maybe its cuz they mmr arent so high...

I finished last season B5, but I know I should be in G3. Actually, no. I am quite a bit better than the gold player I see in blind pick. What is above Gold tier?

it is because you did not win 10/10

http://na.leagueoflegends.com/en/news/game-updates/competitive/2016-ranked-season-kicks-soon "Preseason brought some substantial changes to the game (learn more about preseason here, so we’re again running a soft reset before placements kick off. As with previous years because of the soft reset, you’ll likely place lower than where you ended last year."

So you have to win 10 games out of 10 to get what rank?...

Give me a sec, and I'll check your match history. How many players did you queue with?