Droprates HH mats/FB molds

HeRolc - Harshlands
HeRolc - Harshlands Posts: 3 Arc User
edited April 2010 in Dungeons & Tactics
OK, most people use pwdatabase to see where various molds/mats drop.
Im very confused about real drop rates...

Lets take Empire's back image from 3-2 for example:
Empire's Back Image default drop rate: 0.5556% real drop rate: 11.0416%

As FB mold lets take Sky demon pearl from Ethereal abomination as example:
Mold: Sky Demon's Pearl default drop rate: 2.2200% real drop rate: 49.0081%

Ok so with 2x drop that would mean about 22% drop rate for the gold mat and 98% drop rate for sky demon pearl? doesnt sound really believeable, I killed the same bosses in 2-2 with about the same drop rate(abuot 9% real drop rate) and fb89 boss with almost the same real drop rate aswell(45%)

I killed them both about 15 times, got about 3 gold mats in those runs, 20% chance per run so about 1 out of 5 runs, sounds pretty accurate.
FB89, i killed it atleast 15 times aswell, never seen the mold drop O.o


Anyone know what im doing wrong with calculations? O.o seeing at those drop rates the mold should drop like 1 out of 2 runs.

Would the FB drop rates be listed false on pwdatabase?

Your help would be appreciated!!!
Post edited by HeRolc - Harshlands on

Comments

  • Brigid - Harshlands
    Brigid - Harshlands Posts: 1,332 Arc User
    edited March 2010
    Drop rates are calculated by a series of rolls.

    First roll is whether any items will drop or not. For TT bosses, this is always "yes" because the bosses are level 150, and therefore there's no level reduction. For BH bosses, it's usually between 50 and 80%, since you're higher level than the bosses involved. I believe it's based on the highest level in the squad, but I don't know for sure.

    Second roll is how many items drop. For TT bosses and most FB bosses, this is fixed.

    Third roll is on each item, to see what it is. This is the "Default Drop Rate". "Real drop rate" is the chance that at least one of that specific item will drop. It's calculated by 1-[(1-DDR)^(# of items)].

    Double drops appears to work by doubling the entire series of rolls. That is, it goes through all of the stuff above, twice. Thus it doesn't straight-up double the real drop rate. For an 11% real drop rate, it goes to about 20% real drop rate. For a 49% real drop rate, it goes to about 74% real drop rate.

    Also, note that drop rate and real drop rate are only when any items at all drop, as determined by the first roll. So don't count coin-only drops.
  • HeRolc - Harshlands
    HeRolc - Harshlands Posts: 3 Arc User
    edited March 2010
    Im too dumb to understand what u exactly mean but the boss is lvl 93 and im 89 myself, so its light-yellow named...

    PS: shouldnt the mold drop way more since it has a real droprate of 45%? while the gold mat has 11%?
    and another example: ring of heavenly lord is about 88% real drop rate which means you will almost get 1 per kill, though i killed it about 8 times and only saw 1 ring mold drop O.o
  • Thalos - Dreamweaver
    Thalos - Dreamweaver Posts: 26 Arc User
    edited April 2010
    Maybe i can clear up your cunfusion a bit:
    Every mob has a fixed value assigned to it to determine how often itemdrops are rolled. I'll refer to this as the number of dropcycles.
    For every dropcycle the game will randomly drop 0-3 items, 2x drops expand this to 0-6. Then for every drop you get the default drop rate from the database applies.

    So the default droprate for your mold is pretty low but FB bosses have a pretty high number of dropcycles which explains why the actual droprate is much higher than the default.

    However it should be obvious now that you will not get twice as high chance for a certain drop only because you get twice as many items dropped.
    When killing a mob for a drop which has a 50% actual droprate it won't add up to a 100% chance for 2 mobs.
  • Olba - Sanctuary
    Olba - Sanctuary Posts: 1,776 Arc User
    edited April 2010
    Also, as with all probabilities, they are only accurately applicable to large, very large samples.

    So just because you have a 80% chance of getting something does not mean that by doing 2 runs, you will always get 1.

    What the drop rate means in practice is that the more you kill the same monster, the closer the ratio of items will get to the probability. This comes from the fact that the larger the sample, the lesser the effect of "exceptional" strings, such as streaks of "luck" or "unluck".
    If you disregard what I say because of who I am or because of the contents of what I said, you are a fool.

    Everyone wants to be different, but when you're different you wish you were normal.
  • Pensieve - Dreamweaver
    Pensieve - Dreamweaver Posts: 10 Arc User
    edited April 2010
    Wts Law Of Large Numbers