Hey duessel the generalization of 50% win rate or less to get 1300 holds true for the most part... why? because at the lower levels your odds of running into higher ranking people is lower than facing lower ranked people.
as you move up the rankings, the pool of people to face that rank above you continues to decline. the 50% win rate will fail you once you are about 1330+ or so
why not give it a shot? i backed up my claims in that post simply by umm doing it....
no it is not fool proof --- nor is it the most effective use of time. the fool proof plan is to simply be a better player and get there in 30 games or so
but the 50% win rate is mentioned to give your average player an understanding that 1300 elo is not hard to do