T43 - 2280 BC
Cliff's Notes: CFC researched either AH or BW (will have to look at the graphs on T44). I think Apolyton and CivPlayers both researched Pottery, but Archery is also a possibility for Apolyton.
Demos:
Last turn, the German team researched BW. Later in the turn they revolted to Slavery and did a 2-pop whip, from 7 total pop to 5.
This turn, CFC, CivPlayers, and Apolyton all researched a tech each. CFC did it in 12t, CivPlayers in 11t, and Apolyton in 7t. From last turn, total power increased with 9000, but that includes the Germans whipping away 1000 of their power, so the real delta is 10000, meaning that one or more of the techs likely carries significant power values.
Bronze Working is the obvious candidate, but lets look at the research times: CivFr and Spanish needed 16t, the Germans 15t, and we 12t (effectively 10t). In our case, we were fueled by 2 cottages the entire time, and a third for the last 5t. Put another way, to research BW in 12t requires 18 bpt sustained, which corresponds to 15C or GNP 24.
Lets look at the graph:
CFC reached that number on T36 or T37 - after they settled Terasvin - and increased that to 27 on T40. They probably spent 1t on max gold on T35. They can't have more than 2 cottages up at their capital, and the first one didn't appear until T35 or T36.
I simply can't get the required GNP numbers out of CFC to research BW in 12t.
Instead, I can't shake the feeling that CFC researched
Animal Husbandry. We'll have to look at their power graph next turn to confirm things.
Apolyton got their gold mine up and worked T39, effectively doubling their research rate the last 4t. I think they've researched
Pottery, though Archery is also a possibility if CFC went for AH.
CivPlayers probably also researched
Pottery. Since they grew their second city to size 2 in 4t, but not until T41, I doubt they could get help from their gold mine yet.