Why Apolyton's thread rather than CFC's? Anyways, here are some more
Formula on deciding whether to irrigate or mine-This only applies once cities are at size 20 and have all tiles railroaded and you want to maximize shields.
Flip chance:
P=[(F+T)*Cc*H*(Cte/Cty) - G]/D
where:
P = probability that it will flip this turn
F = # foreignors, with resistors counting double
T = # working tiles under foreign control (out of the max of 21, no matter what the cultural boundaries are atm)
Cc = 2 if foreign civ has more local culture than you, 1 otherwise
H = .5 for WLTKD, 2 for disorder, 1 otherwise
Cte = Total culture of the foreign civ
Cty = Total culture of your civ
G = # garrison units
D = factor based on relative distance to capitals = 2000 * distance to AI capital / distance to your capital (the distance ratio is always between 0.25 and 4)
Now reorganizing this gives the required garrison as:
G = (F+T)*Cc*H*(Cte/Cty)
For other formulas, look in the war academy. Be sure to click discuss it in the forum to get the updated numbers.
Make my head hurt!!! 
(Trying to become a fiend at this game)
