Here's how it works for me, WLWWLWWW, LLWWLWWW, LLLWWWWWW (possibly 7), WLWLWLWWW, if you can manage to get 3 wins in a row you're really in the clear. It usually takes around 3-5 wins above a loss to rank up. Keep that in mind. I've stuck to this ideal and it really helped me rank up, got me hyped for my 3rd or 4th win in a row, caused me to play better and rank up when I did.