Dynamis coins drop mechanics

[MarkovChain]

They can drop 4 coins on nightmare mobs, one is 100% the other 3 are independant.

If p is the probablility for one coin to drop for any slot then you easily get that

proba of 1 coin is : 3*p^2-p^3+1-3*p
proba of 2 coins is : -6*p^2+3*p^3+3*p
proba of 3 coins is : -3*p^3+3*p^2
proba of 4 coins is : p^3
average : 3*p+1

This matches the data with p~=0.64

Data

Em & tough raptors in Qufim
Treasure hunter 6

Nightmare Kraken (Killed 336 times with TH ??)
Dropped 0 items 1 times ( 0.30 %)
Dropped 1 items 13 times ( 3.87 %)
Dropped 2 items 73 times ( 21.73 %)
Dropped 3 items 147 times ( 43.75 %)
Dropped 4 items 102 times ( 30.36 %)

Nightmare Raptor (Killed 429 times with TH ??)
Dropped 0 items 1 times ( 0.23 %)
Dropped 1 items 26 times ( 6.06 %)
Dropped 2 items 99 times ( 23.08 %)
Dropped 3 items 193 times ( 44.99 %)
Dropped 4 items 110 times ( 25.64 %)

Nightmare Snoll (Killed 605 times with TH ??)

Dropped 1 items 27 times ( 4.46 %)
Dropped 2 items 147 times ( 24.30 %)
Dropped 3 items 261 times ( 43.14 %)
Dropped 4 items 162 times ( 26.78 %)

When mixing all 3 mobs you get

1 coin := 0.04817518248
2 coins := 0.2328467153
3 coins := 0.4386861314
4 coins := 0.2729927007
average := 2.921897810

All value match for p ~ 0.64-0.65
Secondly the drop table of each mob matches for this value.