Its an ELO based system. Each rank is assigned a numerical value in terms of points (Silver is lowest, increasing incrementally to GE). How many games it takes until you rank up is dependent on the enemies that you play against. If you play vs opponents with a higher rank (and so overall higher ELO for the team) you will gain more ELO points than if you got the same result versus a team with an overall ELO the same or lower than you. It is also worth noting that the points allocated to a team for a win/draw/loss are not shared evenly - if you are a higher rank than your teammates you will receive a lower share of the points, and vice versa. There are also rumours that K/D has some influence on points allocated. Therefore it is pretty much impossible to calculate specifically how many more matches you need to rank up.
I thought the whole point of getting a rank (I'm Silver iV) was so that you would be matched with people of the same level? Can you still end up in games with people of all ranks? What's the point of the ranking then?
