Originally Posted by Vic47

For some gachas this might be no problem, since they work differently (say, you won't get SRs you've already got from eGacha, unless you'll reset the box, or will only get one of the new cards, available on the list in an Exploration sector), but the amount of the cards on N Gacha just grows and grows over time, since no cards getting removed from it, and the total number increases with every added card, reducing the percentage of the other card drop chances.

You're wrong. N gacha is growing slowly, most new cards are put in eGacha or SR gacha. But the problem with low chances is because Nutkau still putting N cards in eGacha, so you have a lesser chance to expect a R/SR card in the deck and even less chance to see anything different.

I stopped to cash due to this crap.

- - - Updated - - -

Doing the math we got this.

Rate to get a R/SR card from eGacha: 5/6 (because exist a 99% chance to see 1 slot is filled with a N card, without this issue the chance is 1)

Discarding past event and N cards (and measures did by Nutkau like the fiasco with Shuri Tsutsui), slayer cards at 2nd phase of an event are 4 (2 beta + 2 Alpha, 1SR + 1R card per tier), six if the survivor alpha cards from past event are active.

Then, sucess rate to get a R/SR slayer from eGacha (5/6)(6)[(5!)(X-5!)/(X!)]

where X is the current amount of cards in the card list and yes, that is a binomial coefficient (i spread it because i can't put those symbols in forum). The resultant rate is pretty low.

EDIT: taking count what 1 slot is filled with 1 N card.