Cannot receive Haze hero even if she is Purple in the Roster

[somaliecw]

I have in the roster several heroes that are white and one hero (Haze) as purple. The problem is: in 4 days I received a hero only once and it started to be annoying.
Questions:
1. How do I need to set roster to increase probability to have Haze?
2. Why is matchmaking like this: Haze is in every match and only ~15-30% in our team?
3. Can hero pool be increased to de-stress Haze choice?

 

[pipapupa]

I'm curious how many matches have you played in that span of 4 days. Haze is very popular and can assume lots of players have also selected her as highest priority.
I'm bad at math - assuming you had like 20 matches in those 4 days, and at least 10 people selected her as main hero, what would be probability of getting her in 20 tries (assuming uniform distribution) 1 - (9/10) ^ 20, so about 88%?
but you got her once. You just being unlucky in subsequent tries.
Hopefully someone will correct me tho if there are mistakes