I have actually noticed similar behaviour, but also the complete opposite. I have found that new ports in your capital region will always give you more trade
routes, even if the new port does not actually trade (ie it doesn't get a green line). The same seems to be true if a newly constructed port lies
"behind" a port that trades, such as the case you describe with the port in Courland. It seems that the ships will simply stop at the closer port. On
the other hand, I've constructed a trade port in East Prussia (playing as Prussia) that did not give me any extra trade routes, even though all trade would
"pass" Brandenburg, just like trade to Courland would pass by Malmö, Sweden. I did this before patch 1.2 though, so maybe they have revised the
system a little bit. I have found, however, that the bonus is definately not global.
The quote from the guide about ports in Crimea and the Baltic is pretty true, just because you construct a port in the Baltic it will not mean that the port on the Crimean Peninsula will accept more trade lanes than the ones it says it can accept in the tooltip. However, it may very well allow you to get more trade partners, trading through the port in the Baltics. But, for all I know, this might be changed as well. Unfortunately my graphics card has died on me, and until I get a new one back from the store I cannot test anything.
The bottom line is that the system that controls the trade ports and trade lane is f***ing confusing, and the more I try to understand it the more confused I get.
The quote from the guide about ports in Crimea and the Baltic is pretty true, just because you construct a port in the Baltic it will not mean that the port on the Crimean Peninsula will accept more trade lanes than the ones it says it can accept in the tooltip. However, it may very well allow you to get more trade partners, trading through the port in the Baltics. But, for all I know, this might be changed as well. Unfortunately my graphics card has died on me, and until I get a new one back from the store I cannot test anything.
The bottom line is that the system that controls the trade ports and trade lane is f***ing confusing, and the more I try to understand it the more confused I get.
