Board Thread:Dragon City Questions and Answers/@comment-3271569-20130508145250/@comment-1912161-20130511231120

i think i understood a little bit more the concept of breeding (it's really hard to understand).

so.... the 2 dragons' elements and types are used to select which dragons could POSSIBLY be bred. e.g., pirate & poo: terra, water, waterfall, mud, hedgehog, venom, pirate, petroleum, poo, legend (4x). (i ignore for the moment the possibility of breeding the unique dragons as it's possible recently)

let's assume 2 (water and mud) of them are in difficulty 1, 3 (terra, petroleum and hedgehog) in difficulty 2 and 8 (all legends, dark, pirate, poo and venom) in difficulty 3.

now, if in theory the poo and the pirate produce <50 gold (not possible, but let's assume for the moment), then from each difficulty one dragon is selected at random. and at last 1 difficulty is selected at random. so, water and mud have 1/6, terra, petroleum and hedgehog each 1/9, and each other dragon is 1/24.

if now production would be 52, then both water and mud would be selected for difficulty 1, and also 2 dragons from difficulty 2 would be selected. in total 5 possible dragons are there, but the chance of getting a legend goes DOWN, because any of these 5 is selected with same probability (20%=1/5). so we have: water (1/5), mud (1/5), terra/petroleum/hedgehog (2/3*1/5 =2/15= 13.33%) and all others get 1/5*1/8=1/40 or 2.5%.

if production would be 56, it would be the same, as there is no further dragon to be added to difficulty 1. but if production would be 72, then the last dragon of the difficulty 2 array is added, further decreasing the chance of getting a legendary!! 6 dragons are selected, each with probability 1/6. water/mud: 1/6, terra/petroleum/hedgehog: also 1/6, rest has 1/6*1/8=1/48.

once we surpass rating 100, one more dragon is added to the diff 3 slot. thus, the 5 dragons of difficulty 1 & 2 all have a chance of 1/7 (together 5/7), while the difficulty 3 dragons all have a 1/7*2/8=1/28 each,  chances increased again.

with rating 200 even (quite tough with pirate and poo ;)), 3 dragons from the difficulty 3 array are added, thus chances shift to 1/8 for the first 5 (water, mud, terra, hedgehog, petroleum), and 1/8*3/8=3/64 or roughly 1/21.

if we surpass 300, it's 1/9 for the first 5, and 1/9*4/8=1/18 for the others, i.e., 2/9 to get one of the legendaries.

if IN THEORY we surpass 700, then all dragons are unlocked. each possible combination has the same chance, 1/13 for each, 4/13 to get one of the legends.

is that the correct understanding? under those circumstances i can make some calculations, which dragons (and their income) are best to get legend/pure, as long as i know to which difficulty each dragon belongs.