because riot has to put them somewhere in the middle of the rank community to see if they sink or swim. if they sink they go to bronze if they float the are low silver and if they swim they are high silver. average player in rank is silver 5 and being that your s2 chances are your mmr is average and you will play with the newbs and if you do good and win you gain LP and if you lose you lose LP if you are above silver rank skill wise then you can win and beat people at your mmr and below. to get out of silver you need about a 58%win rate to 66% or roughly 2 out of 3 games and 3 out of 5 with streaks of wins to raise your lp rapidly to get to 100 lp to get to promos.