Originally posted by mardukes
a) specifically, the first 50 shields of the wonder must come from a caravan? Or any 50?
b) so the routes being different from the list causes list members to unblock, but are you saying it also keeps the list from changing?
c) this seems contradictory or are you saying that once the SSC gets that big we don't care about the list changing anymore? What is the process for choosing which existing route will be replaced by the new one?
a) I believe that is so - regular shield production or disbanding a unit does not do it. I think you could use an SSC food caravan in another city, but then you do not get the half-start on the new commodity caravan in the SSC. See Solo's EL Guide for more details.
b) No - see Samson's exhaustive Determining Supply and Demand thread to calculate what causes changes in the lists. A supply commodity that is blocked and not listed among the 3 trade routes can be unblocked via WonderBread (or a regular delivery of a commodity); a supply commodity that is blocked and also listed in the trade route list cannot be unblocked deliberately, but if the lists change it can be unblocked (or more likely, another commodity will join the list and something will drop off).
c) When the SSC has a lot of trade it dominates the calculation of the ongoing Trade Route benefit. I dont have the regular TR formula with me at the moment, but it is something like (T1 + T2)/8, where T1 is the number of base trade arrows (subtract existing trade routes) in your city and T2 is that of the destination city. So if your SSC has 100 arrows and the destination city has 1 the TR would be 12 (rounded down), while if the destination has 10 the TR is 13 (AI cities with base trade over 10 are rare birds!). The game program compares the size of the new TR to the three existing ones and only swaps it in if it is larger (the smallest drops off). So if you dont want to cause one of the existing TRs to drop off, see if you can lower the number of arrows just before the caravan enters the city (of course, you will get a lower bonus payment too), or if the destination city is yours you could monkey with its trade before delivery. Once the delivery is completed you can restore the arrows immediately; the TRs will stay the same.
Note that I am dropping consideration of the trade route modifiers, which can skew these calculations significantly but obscure the base city comparisons. In order of effect they are:
-Same civ: -50%
-Different continent: +100%
-"Optimal" Rail connection: +100%
-Superhighways at home: +50% (in both: +100%)
-"Optimal" Road connection: +50%
-Airport at both ends: +50%