Originally Posted by Discoceris

What kind of math is that? 10 + 1 is not a pool, cumulative, or aggregate. All 10 + 1 is the fact that you choose to roll ten times at once, and receive an extra roll for free.

The odds of seeing any one particular girl remains the same. 6★ still has a 0.5% chance, regardless if you rolled once, or ten times in a row.

I myself have experienced at least 3 10+1 rolls where the highest I had was a 4★, and one of those rolls where nothing but 3★.

Edit: To clarify, the quote was assuming a pool which has a fixed number (high end) and also assumes that you will not (a) pull duplicates, triplicates, etc. and (b) that somehow each additional roll beyond the first increases the chances of obtaining something that you had not already obtained. Both do not square away with my experience, and that of many thousands of other players, and no where did Nutaku said that your normal 10 + 1 pull guaranteed anything (Unless there's a special circumstance, like receiving a ticket, but that DOES NOT COUNT when calculating the odds, because the ticket is outside the function of the gacha)

Edit 2: What I think many people don't realize is that gacha follows the same principles as a gambler at a craps table, or any other game of chance.

https://en.wikipedia.org/wiki/Gambler%27s_fallacy

Ah, but avarages do exist, even in RNG. It just doesn't simply work additively, and often you need to make odd calculations to get the results you want. When you plot out all the possible resultsand the chance for them to happen, you get the well known Bell Curve (because it's shaped like a bell). Still, it remains RNG, and people (gamblers specifically) like to take their chances at getting something from the far right side of the curve, even though they have the same chance at ending up on the far left side, and that the peak of the bell curve is just the most common result, but that no guarantee is ever given that you'll actually manage even that result.