Pleikki

Nice

Quote from Pleikki

Dropping one like this has so low odds compared to any other 20/20, better to ask red to do the math haha :p

I'll try...

first up some general stuff:

the prof specific core foci like flame artifact can only drop with attribute specific mods tied to their profession - 3-4 attris per profession

not all attris are available as attri specific mod on os items (no hsr estorage for example)

the anniversary foci can come in all combinations (like req fire, hsr blood, hct heal) - 16 attris for the mods if I'm not mistaken

the anniversary skin foci are about 1/10 as rare as any core skin modelID

from here we can make an approach:

a matching 20/20 anniversary foc will be somewhere like 10 × 16/4 × 16/4 = 160 times as rare as a core skin. means statistically on one matching aniiv foc like that come 160 core foci like that.

Now all this assumes you only farm a specific place that drops both (chests in echo forest hm for example) and you compare the chance of one specific anniv foc to one specific core skin foc.

sticking with the echo forest chest however you would have 70 core skin foc modelIDs in the pool, with an accumulated weight of 61.2 (jug, paper fan and paper lantern being rarer), and 35 anniv foc modelIDs. that means the expect would be a 3.5/61.2 aka 1:17.5 ratio for the anniv foc vs core skin ration instead of the 1:10, which would put us at a 1:280 rate for matching 20/20s. and I was conservative on the chance for the anniv foc, bc the 16/4 ratio assumes attris on professions that have 4 possible attris as hct mods... and I did neglect that there are attris on anniv foci that can't be matching since the respective hct/hsr mod does not exist os - like ES. this is getting a little too manual of adding numbers, I think we are good for a ballpark at this point - likely 1:400 would be fine.

and then you could also calculate the chances for other sources and then weigh them by the amount they are being farmed to see how much you'd expect them in the pool of dropped items globally, but that is impossible since we do not know who farms what how much. but I can tell: you will not get an anniv foc on a charr sword storm in nolani, nor a core skin foc on a mountain troll, nor a monk foc on a charr flame wielder... you know the mechanics (in parts )