Originally Posted by Zandel

I find the 80 stam map has better drop rates but even then when I get a new 6* and need 5 lvl 100 I do not expect to evolve that girl for 3 weeks for so....

It's more like the pool for anything besides low level increases. An example (just an example)

Map	Low	Mid+High	Total
10	70	30	100
20	60	40	100
40	50	50	100
80	40	60	100

As you can see, by lowering the drop rates for the crap, you just increase the chances of seeing other drops more. Gives you the illusion that you get increased chances of the level 100 evolution material, but the percentage may still stay the same regardless: I'm assuming around 5% for level 100 evo mat on every map. This probably explains the still high frequency of crap mats on 80 stam maps...

Also you can be quite devious and say with a straight face, "no you're wrong, the rate of appearance for level 100 is 15%". If you use the math above, you can get away by saying that.

15% of a 30% pool = 4.5% actual
15% of a 40% pool = 6.0% actual
15% of a 50% pool = 7.5% actual
15% of a 60% pool = 9.0% actual

I'm willing to bet that they use similar math for gachas as well, because there's no law that tells them how to breakdown a chance of appearance, so companies could say that the rate they give you is "exactly how we programmed it", not the rate after you run it through a formula. Because, after all, the company is under no obligation to turn over real life data to corroborate the publicly listed rates.