User:SarielV/Statistics/RARD

So you've opened 1467 ToT bags and you still didn't get your Mini Gwynefyrdd. Did you give up too early for something that most players think has a drop rate of 1 in 10000?

Personally, I like 90%, but most statisticians are going to want 95% or 99% assurance.

Notes

• 100.0% is not actually 100%, but the difference is lower than Excel can represent. There is never an absolute guarantee for anything occurring that is not already 1 in 1. Bad luck streaks can go on forever.
• When the chance of getting something is 1 in X, repeating the task X times is only about 63% likely to get you what you want. Streaks of severe bad luck can go for longer than 4X.
  • Conversely, if you think the drop rate is 1 in X, you'll need about 4X trials to be sure of getting at least 1 occurrence (~98% chance at that point).
• Rarity promotion in the forge is assumed to be odds of 1 in 5.
• Forging a precursor from 4 rares is assumed to be odds of around 1 in 800.