I did really well in my provisional matches and got Silver 2, what am I missing?

What is required to get a decent rank of the rip? In my 5 provisional matches, I won every match and was effective in every measure - I was top DMG every game, died very little, played objective, and made plenty of game winning plays. I genuinely do not know how I could have done better in these matches but when it's all said and done, Im placed in Silver 2. What am I missing about the ranking system?