The Hides Caravan

[Theben]

Playing an OCC game, I thought I died and gone to OCC heaven. I had the "repeated commodities" caravan (hides) and the largest AI city in the world repeatedly demanded it! As I sent my 5 'hides' caravans off to Paris I noticed a few things:

-My discovery of Invention killed my ability to make hides caravans.

-My city never got more than one trade route from them. Creating other trade routes may also have killed my ability to make hides caravans (yes, I reloaded after winning)

-Some other commodities had similar "repeated" characteristics. Salt, FE.

Does anyone have more information on this topic?

[East Street Trader]

Only one route being established matches my experience. A city can have multiple trade routes with another city but they must be established with different commodities.

The Invention point is interesting. But just from memory I have the feeling that hides is a commodity I am used to seeing around late in the game and I have a sort of feeling that I have had repeat hides late too. Could be misremembering though - the repeat hides cases of which I have distinct recollections have been early on. So I'll watch out for the Invention point (unless some public spirited soul puts matters beyond doubt by running a test).

I've come across some other commodities that flip/flop as a pair - eg silk changing to wine, then back again - but haven't noticed any other perpetual supply/demand cases other than good old hides.

[Adam Smith]

Not sure if multiple trade routes must be established with mulitple commodities. I have an old game I can check to find out.

I have had plenty of times where, late in the game (ie., after invention) the only commodity available is hides. Therefore, it does not appear that hides stop after invention.

Based on my experience, it does not appear to be the commodity which causes things to flip, but the city. See the Repeated Commodity Trade Strategy Thread, available in the Great Library or Archives.

It may be possible to build perpetual supply and demand cities, and I appear to have built a pair in a current game, though it is still a bit early to tell for sure. Working hypothesis is that the number of comodities that filp in a given city, hence the possibility of creating permanent supply and demand, follows a pattern like Oedo's xxxo applied across the total number of cities founded in the game. Further hypothesis is that the change in the identity of the commodities in a given city follows the "a is for alphabet" mechanism with some modifications for era. Applying these two mechanisms appears to allow you to build a pair of cities which permanently supply and permanently demand a given commodity.

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Old posters never die.
They justfadeaway

[Blaupanzer]

Only one route will appear for one commodity between two cities, demanded or undemanded, no matter how often you send that commodity. Depending on its value in the bonus period, this may still be worth doing, but no 2nd route will appear in the sending city.

[Theben]

Well maybe Invention didn't kill off my hides caravans but they did disappear on the same turn. Anyway I finished that game with a landing on AC in 1925 (prior to reload). No big deal to most of you I imagine, but I haven't tried it in awhile. I also figure that I could have landed at least 50 years earlier if I hadn't done some really dumb stuff that I attribute to playing too late at night.
Anyway now I've got a regular game going and I've noticed that by bombarding a city with various goods you can free up items that were previously locked in a route; i.e. coal, gems, (silver) becomes coal, gems, silver after dropping 3 dyes and one gold into the city. Kind of interesting.

[Edward]

Theben,

That would lend support to my theory on how the "tying up" of available supply and demand commodities works.

Any city that receives a caravan has the potential to tie up that commodity as a supply option in the city that sent the caravan. (Putting that commodity in parentheses in the supplying city's city window.)

A destination city ties up supply commodities in a source city only if both:
1) the source city sent a commodity that the destination city demands and
2) this particular route from the source city is one of the destination city's three best trade routes (as judged by permanent trade arrows).

Only when this happens is that demand finally met and put in parentheses in the destination city.

If you only meet the first criteria, but not the second, you still get the "meet demand" commodity bonus to your one time gold and beaker reward - you just don't tie up any commodities.

Note that the source city still gets permanent trade arrows from the route (regardless of whether it meets any of the criteria) as long as the new route is better than all the existing routes (permanent trade arrow wise) in the source city.

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Theben,

This means that City A could send an undemanded bead caravan to City B and, surprise, City B could have one of it's previously met supplies suddenly become unmet (also freeing up that commodity as a supply option in the city that previously met it)! This would happen if City A had a relatively large number of natural trade arrows so that when it's undemanded caravan set up a route with City B, this new route was better that the third best route that City B already had, thus kicking that demand-meeting route off of City B's top three list.

This example is what I postulate happened to you. The final dye or gold caravan you sent came from a trade-rich city thus making a new trade route which was better than the silver route that city previously had. (Not only was your new route better than the previous silver route but also the silver route would have to have been the third best route that city had. It wouldn't surprise me if some of the earlier caravans you sent helped bump that silver route down in the city's top three list until you finally established three better routes.)

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Adam Smith,

This means that City C can send a demanded silk caravan to City D, and yet, surprise, City C can still make silk caravans! This would happen if City C had relatively few natural trade arrows so the new silk route was worse (in City D's eyes) than City D's other three routes.

I postulate that this example is what causes the Repeated Commodity Trade situation you describe. What's really happening is that the destination city (call it City E) already has three really good routes and also has one or more unmet demands. Whenever a new caravan arrives with a demanded good (say from City F) it can't compete with City E's three established great routes. Thus City E doesn't have it's demand tied up, nor does City F have it's supply tied up.

The dream ends when some city (maybe even City F after being beefed up by some "We Love" days or centuries of growth) not only meets City E's demand but does it with a route that's more lucrative (permanent trade arrow wise) than City E's previous three best routes.

This seems to match some of SCG's experiences:

quote: In one game I had an AI capitol demanding dye. With some experimentation, I found that if i delivered the smaller payload dye caravans first, I could deliver more dye caravans before the AI demand changed or was satisfied.

Here the initial smaller dye caravans aren't beating the existing three routes in the AI capitol. Once one does, the demand is met.

The fact that you rehome all your caravans in your SSC throws a wrench in this explanation. The only thing I can think of is that the magic cities already had three undemanded routes from your SSC (or some really big AI city). Otherwise your first demanded caravan from your SSC should have met my criteria and tied up the demand in the magic city. After the magic city had three great undemanded routes, the new trade routes from your SSC would at best tie the old routes in quality (having same number of permanent trade arrows as the previous routes which are also from your SSC) so the new routes would never meet my second criteria by virtue of never being better than the three established routes.

I guess I'll need to test my theory further.

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Of course, this theory doesn't address the mysterious changing of types of supplied and demanded commodities. (e.g. Thebes used to demand silk, coal, gold - now it demands silk, coal, dye - go figure).

[Scouse Gits]

I have given up trying to predict or make sense of the trade pattern in the game.

There have been games when Gold is demanded by an AI city for two or three turns then the demand vanishes!

Silk has been my most profitable repeating commodity. One game it was produced by several of my cities and demanded constantly by an AI capital! During this game my home continent had several silk specials and so did the AI receiving continent. Has anyone examined the proximity of certain terrain specials to cities and looked at the trading supply/demand for those products?

SG(2)

[East Street Trader]

I've kept an eye on that SG, just while playing - not by testing. Sadly my conclusion, for what it is worth, is that it isn't a factor. Not for silk, spice or gold.

I am confident that certain civs have an affinity for certain commodities and also that demand and supply of commodities cluster themselves on the map (so that neighbours are very likely to share the ability to supply a particular commodity or to demand it). I nearly always thrive in a game where numbers of my core cities produce silk and a reasonably distant yellow civ has several cities demanding it. With a ship chain in place in such a game you can get an advance a turn without great effort.

I think that gold is programmed to be demanded for a short time by trade rich &/or large cities in the early middle game. So, in my experience, you can almost count on there coming a point where the capital of the yellow civ will demand it followed sometimes by the next biggest of the yellow civs cities. I have (succesfully once or twice) built a gold caravan when gold was nowhere in demand in preference to a low value demanded commodity and transported it towards a likely looking city (probably yellow) on spec hoping that by the time it arrives the brief period of gold demand will have arisen. If you build a gold caravan in a high trade capital/principal city and take the gold to the other side of the world you might bring in a 500 gold and beaker bonus at a stage when maybe getting gunpowder in one turn or quickly acquiring the ability to build ironclads is going to open up a really good window for conquest.

But this might be a particularly difficult trick to pull off on the large/giga maps you favour.

It is probably imagination, but I think there may just be one of the "Egytians get Masonry more often" features here because if the Spanish are the yellow civ gold seems to be more often in demand and for longer.

There is a persistent theory that cities built on mountains, or with mountains next to them, are more likely to produce uraneum late on. Can't confirm or deny that one at all.

Consistent generation of uranium is a holy grail which eludes me.