For the tests, I focused on the French border city of Rennes, that had not defected to me until 1862 in my original game. I reloaded back to soon after 1200 and built a bunch of settlers and then arranged them immediately next to the city border (the city stuck out into my territory and was a modest 9 tile effort).
I put 5 hard up against Rennes border and two more a few tiles back. When they were in position I saved the game (Save A). I then had them all found their cities, and saved again (Save B). This was 1250 to 1255.
Using save B and re-running the game 7 or 8 times produced fairly consistent results a flip in around 100 years (20 turns, as opposed to the original 600 years and 150 or so turns). Re-running under the same conditions gave flips within a turn or two of the same time.
Varying the amount of culture also seemed to have an effect obviously the more overall culture points the faster the flip. However, I couldnt prove either way whether extra culture in the besieging cities helped much or whether building temples etc there helped by simply adding to the empires total culture. If I built no culture at all in the besieging cities, Rennes still flipped it just took a few turns longer.
However, if I reloaded using save A (pre actually settling the sites) the results came out differently. Not only were the flip times different (by up to 100 more years) but the cities that flipped also varied. On one occasion Brest flipped first (close but not surrounded by the besiegers) while Rennes shrank to one tile and stubbornly sat there. On my final attempt the first city to flip was Strasbourg (which had two more French cities between it and Rennes) in 1375. Followed by Toulouse (1390) the New Tours (1500) and Bayonne (1535). Brest didnt flip and neither did Rennes which did its one tile sulk act. Finally, Rennes flipped in 1740 (nearly 100 turns from when I started the test).
Does this prove anything other than Im a nut who just wasted a whole lot of playing time? Well, Id say that it probably shows that changing your other goals to try and manipulate the situation often isnt worth all the effort. I also believe that it shows that there is a strong likelihood that a partly random decision is made about the chance of a neighbouring city contributing to a flip and that the decision is made at the time the new city is founded. Later culture additions are then added to this calculation and the whole lot accumulated. Either way, its a heck of a lot for the game to keep track of given the huge number of cities and potential inter-relationships across a whole map.
Who know? One city in one game may not prove much. Ah well, back to the game!
:crazyeyes :crazyeyes :crazyeyes