There are different ways for implementing auto negotiation:
a) Randomly selecting a combination that is selectedable (can suggest anything as long as it is not a red resource or a resource that already was yellow on that spot), so things like this can happen:
https://forum.beta.forgeofempires.c...uto-select-for-negotiations.15130/post-127216
b) Randomly selecting a possible combination
c) Randomly selecting a combination that has the highest chance of solving the negotation
d) Selecting the combination with the highest chance of of solving. If there are multiple options, select the one that is cheapest (resource costs need to be weighted to use coins before goods and goods with high inventory first)
Currently Option a) is used, but in my opinion it is too dumb to be actually useable
Option c) and d) only work with precalculated data as calculation overhead would be too high especially for 4 turn negotations. Also it would need too many developer resources.
My suggestion would be going route b) Otherwise you will be confronted with a lot of bug reports when the suggested solution is obviously wrong.
Then auto select can be used for 3rd round because in round 3 every possible solution has an equal chance of solving.
For round 1 I suggest this optimization:
.) If 5 or more resources are available select 5 different goods
.) If 4 resources are available select 4 different goods + 1 good twice
This can be implemented pretty fast with:
GoodNumber = SpotNumber MOD ResourceCount
Edit:
Another option would to to present the auto select option only in first round and automatically solve the negotiation at the average goods cost.