Theorycrafting: The likelihood of drawing SR and SSR kamihime in Gatcha

[sanahtlig]

I've prepared a user-friendly spreadsheet allowing users to manipulate some of the analysis parameters. This will allow users to figure out their chance of getting kamihime in a given number of rolls, and also allow the analysis to be easily updated as the Gatcha is updated in-game.
Sanahtlig's Kamihime Project R Theorycrafting

Explanation of methodology and summary of results

I originally assumed, as did many others, that the likelihood of pulling a kamihime, a non-kamihime weapon, and an eidolon was proportional to the number of possibilities in a given rarity tier. This turned out to be FALSE. The data collected from 1000 rolls show that the rate of pulling a weapon vs. an eidolon is about 50% across all rarity tiers. Conversely, the relative rate of pulling a kamihime (vs. a non-kamihime weapon) increases with increasing rarity (which is offset by the diminishing chance of pulling a given rarity). This unexpected result required the analysis to be redone. I also factored in the guaranteed SR+ on 10-rolls. Note that the SSR rates are based on an insufficient number of data points (11 kamihime draws) and therefore are only approximate (I need 2000 more rolls or 200 10-rolls for the rates to be reliable).