It is funny because when Im on that non-5* streak, I always get it on 4.75%. Also every single time, When one of banner reach 4.75%, I summon one on other banner that is 3.00% and like half of the time I get 5* focus hero XD. That is how I got B.Char, W.Tharja. I didnt even try to summon those banner but just spent 5 orb after free one once other banner I was focusing reach 4.75%. It might be just luck but that has been happening to be for couple month now.