One very good thing that was in hearthstone rng. was chance to get legendary card.
when you open booster pack you have a chance to get legendary. if you don't get it you will have increased chance to get legendary from next pack. up to 40th pack.
so if you are super unlucky and didn't got legendary in first 39 packs.
you have 100% chance to get legendary in 40th pack. after that counter is reseted
similar thing would be awesome in this rng.
for example. glory keys.
you have 0.5% chance to get legendary in first chest. i you don't get it then next chest will have chance of 1%.
same with mythics.
0.1% chance to get mythic. so after opening 1000 gem chests you have guaranteed mythic drop.
I remember when I got my first mythic.
I was about lvl 50-60.
Of course I was happy, but in chat I saw people who are lvl 200 and didn't had any mythics yet.