How To Maximize Trade Between Two Cities?

[rjmatsleepers]

This example does not involve foreign trade, but it does show a lower value route replacing a higher one. Unfortunately it involves hides which may be significant.

There is a hide caravan from Avalon about to be delivered to Gloucester. Gloucester has 3 existing routes - 2 with Camelot and 1 with New London. Camelot has a base trade of 9 arrows while New London has a base trade of 8 arrows. Avalon has a base trade of 8 arrows. However the delivery of the caravan displaces one of the Camelot routes.

Am I miscounting the base trade? Have I misunderstood the way in which routes are supposed to be replaced? On the face of it, what happens here does not conform to the "rules".

RJM at Sleeper's

[Zenon]

RJM, I have checked your example and agree that the replacement of the trade route is not as predicted. On the other hand, this seems to be a special case. Gloucester shows 2 trade routes with Camelot while Camelot only shows 1 trade route with Gloucester (no other trade routes). I suppose that Camelot is a hides repeater. Gloucester is a hides demander. When delivering the same commodity again to the same destination city the destination city gets another trade route whereas the source city does not. That´s obviously what happened on the Gloucester/Camelot trade route. Avalon also has delivered hides to Gloucester allready and is now delivering hides again. What happens here is the replacement of one incomplete trade route by another. May be that´s the reason. Anyway, a very interesting case that leaves some questions open.

Zenon

[Elephant]

Trade Route replacements and domestic route values are bedeviling me too. Sometimes a new delivery replaces an existing one, sometimes it replaces one from a different city. I've been doing control tests with a "cheat" map, but the reasoning behind the differences still escapes me. And I've seen several cases where the value of a route between two of my cities has been off by 1. I will look into the issues of one-way routes and whether Hides makes for special cases.

Thanks for giving your example with a 2.42 save, too.

[rjmatsleepers]

Originally posted by Elephant
I will look into the issues of one-way routes and whether Hides makes for special cases.

I believe that I have had the same thing happen with deliveries of goods other than hides, but unfortunately I can't find a save to show it at the moment. And in any case, it may be that one of the routes involved was originaly set up with hides.

RJM at Sleeper's

[rjmatsleepers]

Originally posted by Zenon
When delivering the same commodity again to the same destination city the destination city gets another trade route whereas the source city does not.

Zenon

BTW, is this true of any commodity or just hides?

RJM at Sleeper's

[Zenon]

Thinking of this problem again it might also be that replacement works sometimes differently if the values are very close. In RJM´s example it was only one beaker. If you take one more beaker from the trade base from New London the trade route is replaced as expected.

RJM, not getting a trade route in the source city when delivering the same commodity to the same destination applies for any commodities, not only for hides. But that´s a rare case unless rehoming is used.

Zenon

[rah]

Yes, prior to outlawing rehoming in our MP games we saw a lot of strange things.

[Zenon]

Indeed, the creativity in inventing exploits that have to be banned again in MP games is admirable. BTW, does Rah - Rules stand for Regularly abandoned hoaxes?

Zenon

[rah]

Hmm, I thought it was Routinely Approved Hijinks.
But your's will do.

[sirsnuggles]

Doh! Looks like Elephant posted while I was away. His calculations are correct except for a couple of exceptions (to be redundant).

1) Corruption lowers the value of base trade a city produces
2) Corruption lowers the value of the resulting trade routes (Hence if you change the gov to democracy you will see what the real trade route value is). Even though the true value of a trade route should be 10, high corruption would lower that amount considerably.

For example:
Tianjin (Chinese) has a trade route with Lyons (French). Both governments operate under Monarchy.
The base trade for Tianjin is 41, Lyons 48.
The trade route should be (41+48+4)/8 = 11.
Now corruption lowers the base route to 17 (Tianjin is a far away from Beijing; distance = 24) and 39.
(17+39+4)/8 = 7.
Now, because of corruption those additional 7 arrows will be reduced by 4 to 3 (7-4=3) arrows.

If Tianjin benefited from a road bonus, then the 7 would be modified to 10 (7*1.5), and reduced by corruption to 4 (10-6=4).

Hence, Tianjin's total taxable trade (under monarchy) will be 17 + 3 = 20.
A change to democracy (for both Chinese and French governments) would result in a much greater taxable trade: 41 + 11 = 52. That's a hefty difference.

Note: the arrows after corruption are what are modified by the road, RR, etc bonuses.
3) Also, the bonuses derived from roads and railroads are not cumulative with the airport bonus. When an airport bonus exists in a city, if that city also derives either the road or railroad bonus then the airport bonus is eliminated.

Here's a table:
Road = +50%
Railroad = +50%
Airport = +50%
Road & Railroad = +100%
Road & Airport = +50% (not 100%)
Road & Railroad & Airport = 100% (not 150%)

4) As I think Elephant was saying, the continental location of cities with airports does not affect trade routes, i.e. you get the bonus regardless of what continent (same or different) the cities rest upon.


I built a spreadsheet several months showing the exact formulas used, but I haven't posted it yet. Since I just lost my job yesterday, I might have the time to post a presentable version. My spreadsheet covers nearly all of the calculations in the game (concerning city production).

If anyone has questions...well I'm sure you'll post them.

[sirsnuggles]

PS. Whenever a new trade route is established, the computer always chooses the highest three trade routes. Hence it is important to calculate them correctly by accounting for corruption when predicting which three the computer will choose. If you fail to account for corruption then you will be surprised when a new trade route that you thought would be high isn't chosen-corruption decimated that high trade route.

Yes, when a source city establishes a second route with the same city of a commodity already being supplied, that source city will not gain an additional trade route. In other words, all three trade routes must be unique in regards to city and commodity. A source city can supply two hides routes, but they must be to different cities.

[rjmatsleepers]

Originally posted by sirsnuggles
PS. Whenever a new trade route is established, the computer always chooses the highest three trade routes.

This is not the case - see the example I posted above where there is no corruption in the source cities and yet the new route does not displace the lower value route from New London. But as Zenon points out if New London is reduced by 1 arrow, it does get replaced. Zenon also points out that the anomolies happen when the values are close. Could the algorithm be more complex than we realise and involve some rounding?

RJM at Sleeper's

[Scouse Gits]

Since I just lost my job yesterday,

That sounds like bad news -- I'm sorry.

Stu

[Elephant]

Originally posted by sirsnuggles
3) Also, the bonuses derived from roads and railroads are not cumulative with the airport bonus. When an airport bonus exists in a city, if that city also derives either the road or railroad bonus then the airport bonus is eliminated.
...
4) As I think Elephant was saying, the continental location of cities with airports does not affect trade routes, i.e. you get the bonus regardless of what continent (same or different) the cities rest upon.

My testing was not rigorous enough. I noticed that the Airport bonus was not taking effect between two cities on the same continent; I had just finished testing RD/RR bonuses between those cities, and did not remove them to test independently. Airport bonus did effect cities on different continents, but there was no RD/RR bonus then. Mea Culpa. I shall restest Airports more carefully. Thanks for catching that.

Practically speaking, I always shoot for RailRoad, then SuperHighways, and leave Flight off as long as possible to extend Colossus, so Airports are late-game, low-priorities (but they do help move freights faster). All this really means is that the best we can do with the Transport Multiplier is +100% for RR on the same continent, and +50% for Airports on different continents. Early game, the bonus payments for deliveries off-continent are higher, but once the RR line is ready that will be the cash cow for the SSC. Building that line, and keeping it from getting blocked by maintaining an alliance, and using that alliance to help the AI city get as much trade as possible, should be the primary foci of those seeking maximum Trade Routes.

[sirsnuggles]

I concur with your assessments.

[Zenon]

Nice work, sirsnuggles!

Practically speaking the influence of corruption should be considered when choosing an AI city as a trading partner. The closer to their capital the better. ( why did I never think of this before, it´s pretty obvious)
Also, if the SSC is not the capital building a courthouse has actually a greater effect as it counters the negative effects of corruption on base trade and on overall trade. I guess we should also list the courthouse when taking about city improvements influencing trade routes.

Originally posted by sirsnuggles
PS. Whenever a new trade route is established, the computer always chooses the highest three trade routes.

What is meant with highest here?

Zenon

[sirsnuggles]

Let's say that three trade routes already exist. If you attempt a fourth route, if that fourth route is larger than any of the previous three, than the lowest of those other three is kicked out. Now, the value that the computer uses as an evaluation is the final value of the trade route after all bonuses and corruption has been considered.

I don't recall seeing a route that would produce higher trade arrows fail to be implemented, except if the source city has already sent a caravan of the same commodity to the destination city.

Thanks Stu.

Stu, I have just read of your loss. I'm sorry. RL took me for a time, and I'm just now getting back to Civ2, otherwise I would have responded earlier.


Anyone else going to see Matrix 3 this weekend?

I'm predicting that Zion is another Matrix, and that physical reality doesn't truly exist. The movie seems to be gnostic in nature, and that's what gnosticism is all about: that physical reality doesn't exist.

[rjmatsleepers]

Originally posted by sirsnuggles
Let's say that three trade routes already exist. If you attempt a fourth route, if that fourth route is larger than any of the previous three, than the lowest of those other three is kicked out. Now, the value that the computer uses as an evaluation is the final value of the trade route after all bonuses and corruption has been considered.

I don't recall seeing a route that would produce higher trade arrows fail to be implemented, except if the source city has already sent a caravan of the same commodity to the destination city.

So ...

... the new route displaces the lowest of the existing three routes except if the source city for the new delivery has already sent the same commodity. In this case the lowest route only gets replaced if the route value is two or more trade arrows lower than the next highest route.

That sounds like a pretty complicated rule and at the moment I can't think why the designer or programer would do it that way.

I still suspect there is something more complicated going on that we don't fully understand.

RJM at Sleeper's

[Zenon]

Originally posted by sirsnuggles
Let's say that three trade routes already exist. If you attempt a fourth route, if that fourth route is larger than any of the previous three, than the lowest of those other three is kicked out. Now, the value that the computer uses as an evaluation is the final value of the trade route after all bonuses and corruption has been considered.

I don't recall seeing a route that would produce higher trade arrows fail to be implemented, except if the source city has already sent a caravan of the same commodity to the destination city.

Sirsnuggles, I have added an example where a lower valued trade route replaces a higher valued trade route. In this sav a freight from Thebes is activated and can be delivered to Memphis. Memphis currently has 3 trade routes with Ur at value 32. After delivery one of these trade routes has been replaced by a trade route to Thebes with a value of only 15.

But I have also found another example where a delivery from a city with higher base trade does not replace theses Ur trade routes. Close to Giza are several freights waiting to build Apollo in time. The gold freight from Pi-Ramesses can also be delivered to Memphis. Even with maximized trade base (higher than the trade base of Ur) the trade routes are not replaced. I am afraid that the assumption that the replacements follow the trade base is also in doubt. There are are many examples that work with the trade base but I can´t explain the exceptions.

Zenon

[rjmatsleepers]

Originally posted by Zenon

Sirsnuggles, I have added an example where a lower valued trade route replaces a higher valued trade route. In this sav a freight from Thebes is activated and can be delivered to Memphis. Memphis currently has 3 trade routes with Ur at value 32. After delivery one of these trade routes has been replaced by a trade route to Thebes with a value of only 15.

But I have also found another example where a delivery from a city with higher base trade does not replace theses Ur trade routes. Close to Giza are several freights waiting to build Apollo in time. The gold freight from Pi-Ramesses can also be delivered to Memphis. Even with maximized trade base (higher than the trade base of Ur) the trade routes are not replaced. I am afraid that the assumption that the replacements follow the trade base is also in doubt. There are are many examples that work with the trade base but I can´t explain the exceptions.

Zenon

Interesting ...

... when Thebes has a base trade of 32, the new route does replace one of the UR routes. If Thebes is reduced to a base trade of 29, none of the Ur routes are replaced. Ur seems to have a base trade of 18 less corruption of about 3. I wonder if it is significant that this is less than half 32, but more than half 29?

RJM at Sleeper's

[Zenon]

Originally posted by rjmatsleepers
I wonder if it is significant that this is less than half 32, but more than half 29?
RJM at Sleeper's

Yes, indeed! I have done some more tests on different maps and I think I can add some findings to the research work Elephant and sirsnuggles have done as far as the trade route replacement is concerned.

Basically the replacement of trade routes is calculated on the trade base. When you try to establish a 4th trade route the trade route with the city that has the lowest trade base of the 4 possibilities is abandoned.

But there are modifiers that apply on the replacement of trade routes, too. It is the qualified road/railroad connection, the 2 airports bonus and the 50% reduction on domestic trade. Road/railroad and airport bonus apply only on the trade routes that are to be replaced. They are not considered for the value of the trade route that is about to be established. The domestic reduction is only considered when the delivery is going to the AI, not when an AI trade route is about to be replaced by a domestic delivery. Superhighways only improve the trade base.

The modifiers are the same as descibed by Elephant and sirsnuggles for the calculation of the trade route value.

There are still some minor exceptions. If the (modified) trade bases are very close (1 beaker difference) or equal trade routes are sometimes replaced and sometimes not. This process somehow escapes me. But otherwise it works as described above.

Zenon

[sirsnuggles]

What do you mean by "a one beaker difference." Are you referring to how the game distributes the final trade into its three components (that is, beakers, gold, luxuries). If so, I have those formula's; there is a predictable rhyme to their madness.

[Elephant]

Originally posted by Zenon

But there are modifiers that apply on the replacement of trade routes, too.

I have been playing with these issues in recent tests. I will look into what you say this next week. Thanks for working on that side of things. There is still some question in my mind about the rounding of domestic trade reduction, too.

[Straybow]

What do you mean by "a one beaker difference."

I think wherever Zenon has said "beaker" he has meant "trade arrow" (at least, in this thread).

[Transport modifiers] are not considered for the value of the trade route that is about to be established.

If that were true, how could any delivery to or from Toledo (+7 w/o road bonus) displace a Cordoba-Madrid route in this example?

[Straybow]

Was that delivered by African swallows or European swallows?

[Zenon]

Stray,

yes I meant trade arrows. I am sometimes struggling with the language. Could you post or send a .sav of your examples? That would be helpful. I can´t look for a reason with the city screens alone.

Zenon

[Straybow]

[Thoddy]

In the example Cordoba demands beads and
it seems, an older route was replaced by the actually demanded beads-caravan route

Test the same configuration with a non beads caravan from Valencia.