Possibly some refreshing news for SSC freights

[solo]

After looking over the log of samson’s 16 AD game, I was really impressed by how many times his SSC was able to produce commodities for trade. Having this happen was almost as effective as using the rehoming exploit to maximize delivery payoffs. If a reliable way could be found to refresh an SSC’s commodities, very early landings may be possible even with larger maps, by trading more intensively. Doing this would increase income needed to build spaceship parts and would provide more opportunities of netting two techs per turn in the latter half of a game.

So I’ve taken a break from EU2, and have been running some tests on a city which is a hides repeater (which I believe is quite similar to samson’s SSC in his game), and while doing so may have stumbled upon what appears to be the surprisingly simple mechanism for refreshing freight commodities. It is simply timely deliveries. Each time a freight commodity was delivered in my tests, the supply was refreshed. In my tests with this city, I was delivering to an adjacent city, and was able to refresh the supply once a turn, and countless times. In samson’s game, where airports permitted very rapid delivery, I’m betting he was able to refresh supply in his SSC so quickly and so often for the same reason.

Next door deliveries, such as in my tests, are not worth while, even though they reliably refresh supply, because the payoffs are minimal, but airports add the bonuses of distance, separate continents, and possibly delivery to a foreign civ. When the airport bonus is added in, payoffs can be substantial, as was seen in samson’s game. More tesing is needed, but if timely delivery of freight commodities turns out to be the key in refreshing supply, intensive trading between airports may lead to some really interesting results in future games.

Another reason I have been experimenting with a city that repeats hides is that if a SSC happens to be one of these, hides can refresh itself enough to keep the SSC trading profitably until freights and airports are available to keep things moving nicely later on.

Looking into how a hides repeater behaves could also provide insight into how the refresh mechanism works, because I have already observed some interesting and unexpected things while running tests. For example, in some tests hides stops repeating after awhile, but in others, it lasts all the way up until the regular freight commodities kick in and take over. I want to figure out why.

Rehoming got me a 776 AD landing on a standard sized map, so I believe that refreshing an SSC’s supplies puts a 500 AD landing well within range, but for now it’s back to make some more tests.

[Scouse Gits]

Yes I realised this aspect in one game when my SSC had nothing to build but food freights. These were stored for building Apollo. I noticed commodities became available when I built the wonder. Ever since I have always used SSC food freights immediately. A handy technique is to use a useless wonder like Women's Suffrage to start things going in another city -then convert to Apollo when Space Flight arrives. Thus avoiding any SSC freights hanging around.

City size is important for gaining new commodities. A growing city never seems to be short of supply items. When growth stagnates it seems that supply commodities follow suit.

------------------------

SG(2)

[solo]

SG,

Yes, I noticed that about storing caravans and freights, too! Using them in some way often opens up the supply again. I used to be reluctant to use up commodity caravans when building wonders, until I noticed that they were immediately re-supplied afterwards.

I very much like your idea about city size being a supply stimulant and will be testing that soon. So far, in tests with tiny cities, those without hides are only supplying the initial 3 commodities, but so far, those with hides have all been hides repeaters.

Something new to me about trading hides is that they take away the supply of one commodity of the city they are sent to. If you send 3 hides to a city before it builds any of its own caravans, all it will be able to make is food, UNLESS it also supplies hides itself.

So far, I am not noticing the 10 tech correlations samson spoke about, but my tests may not be reproducing enough of the similar conditions that develop in an actual game.

[samson]

Solo,

You are exactly right about the importance of understanding commodity resupply. If you can assure your SSC of available commodities, it is nearly as effective as rehoming, without the stigma. While I don't understand the algorithm involved yet, I am convinced it is non-random. In my opinion, the factors operating on both the supply and demand of cities can be determined with some clever test design and careful observation. Here are some ideas, in no particular order.

1) Hides is a special case. You never see "(Hides)". I believe this is a programming glitch. Thus, while Hides is an important factor in gameplay, it may be misleading in trying to understand the operation of supply and demand with other commodities.

2) The commodities supplied by a city (and perhaps its demanded ones) are determined by a number of factors: terrain, location, size, number of acquired techs, others???. How these factors combine to determine which commodities are supplied, I don't know.

3) In addition to the factors that determine what is supplied, there may exist 'trigger' events which actually intiate the changes by forcing the game to recalculate them. I suspect these trigger events are trade-related, such as building a freight, delivering a freight, receiving a freight.

4) There are tactics which can make unavailable commodities, i.e. those listed in "()"s, available again. Key to this is getting a fourth commodity. By understanding the order in which existing trade routes are replaced by new delivered commodities, you can target those routes which are tying up a commodity in your supply list. Replacing that route, makes its commodity available again. I used this tactic repeatedly in my 16AD game.

5) Yes, using freights in Wonder building, even food freights, often frees up commodities. In one case, I observed that it actually freed all three commodities for resupply.

I'll post other ideas and discoveries to this thread as I come across them.

[solo]

I'm working on SG's city size idea, and this is hot stuff, I think, in solving the refreshing problem.

Working with a non-hides city, I've done some preliminary testing of the relationship between a city's size and the refreshing of commodities, and have some preliminary, but repeatable results:

1) The first three commodity caravans can be built any time, but if they are all delivered before the city size thresholds are reached, the city sizes that allow a new commodity do not seem to work.

2) The three city size thresholds are size 7, 10 and 13.

3) When a city reaches size 7, the fourth commodity will be available right after delivering one of the first three.

4) Likewise, at size 10, if one of the earlier caravans is saved for a delivery then, the fifth commodity is released.

5) So in both cases, the city size allows the new commodity, but the new commodity only shows up after a previous caravan made in the city is delivered. (By the way, the caravan will also trigger the next commodity's appearance if it is added to a wonder being built.)

6) Size 13 is when things really get to be fun, because if one of the first 5 caravans from the city is delivered now, it triggers the alternating commodity effect, when the 6th commodity becomes available. Immediately after this one is delivered, the seventh becomes available, which when delivered, refreshes another copy of the sixth, which in turn, leads to the next copy of the seventh. This is similar to the effect by which freights are resupplied, as described in my first post above.

Now I'm guessing that this rotating effect is not allowed to go on for caravans, indefinitely, but if it can be sustained for any length of time, this means reaching size 13 in the SSC ASAP may become a bigger priority.

samson,

I am also well convinced that resupply is NOT a random event. For caravans, city size seems to be the key. Timely deliveries (or use in wonders) seem trigger the resupply of both caravans and freights. I have also oberserved that food deliveries will act as a trigger in cases where all the commodity caravans or freights have been used or delivered too soon.

City locations, and maybe the civ type, itself, probably help determine the particular commodities that appear in the supply and demand categories, and since commodities can vary quite a bit in inherent value, it may be worth running tests in trying to predict this aspect, too, but for now, I'm focused on the resupply issue.

The supply (or loss of it) of commodities in target cities can also be affected at the time a delivery is made to them. I have also observed that a delivery sometimes alters the supply list in the targeted city. You are right on the money with those observations.

What I haven't noticed yet is any effect of tech acquisition on supply, except for shortly after the transition is made from caravans to freights.

[solo]

Some more of my tests result in a few more notes:

1) When a city reaches size 13, it may be necessary to deliver all caravans associated with it to enable the re-supply of the 6th commodity and get access to it and start the rotation with the 7th going.

2) I am now almost convinced that a caravan or freight delivery (or using one up for a wonder) is the only way to trigger commodities that have been enabled for re-supply. Many times a city is in the enabled state, only waiting for a caravan to be used up in order to display, and make available, a fresh commodity.

3) I am also convinced that there are other conditions, in addition to city size, that can enable a city for re-supply, even after all its own caravans have been delivered or used up. Even in these situations, another caravan has to be used up to clear the way for the next re-supply of another commodity. Sometimes the trigger for a city is right after it receives a commodity from another city. Sometimes the enabled city has to build and use a food commodity first. Which trigger to use is not yet obvious or predictable.

4) Unfortunately, and I have verified this with repeated reloads and tests, there does seem to be a random factor involved, in situations where it is NOT an enabled city’s own COMMODITY caravan being delivered or used up. For example, many times I was able to send a commodity caravan from one city to another and get different results after reloading and repeating the process, i.e. the target city would re-supply on some attempts and wouldn’t on others. It may be possible that reloads do not perfectly save the state of cities which have become enabled, too, making different results of the exact same delivery seem like they are randomized. However, if randomization of re-supply is being done purposely, this throws a monkey wrench into attempts at unraveling the re-supply puzzle.

5) After some tests, my suspicion about hides is that their unusual behavior may not be a programming glitch. Each time I have delivered hides a parenthesis has gone around one of the target city’s supplied commodities, to replace the one that should have been around hides. This may actually be on purpose to make the supply and re-supply issues more convoluted and harder to unravel, much in the way that “joker” techs drove Oedo nuts when he was trying to unravel tech tree progressions. Hides may be the “joker” commodity.

6) Building and delivering food commodities will enable a city, but the catch here is that a valuable caravan is used up just to give another city a full food box. In addition, doing this does not always trigger the fresh commodity. Sometimes another delivery to or from the city is needed to trigger the actual re-supply. Sometimes a brand new food commodity will act as a trigger if used to help build a wonder, too. However, a food put into a wonder does not seem to enable a city.

7) So in conclusion, there seems to be a two step process in getting a city to re-supply a commodity. First, it has to be enabled in some way, and this may often occur at random. Once a city is enabled, the re-supply is always triggered by using up a caravan or freight.

[rah]

From experience in mp games i have noticed that what a city supplies and demands can change when other civs complete researching or acquire certain techs.
Trade being one of them. I've seen my sup/dem change when waiting in between turns. When this has occured, i've asked if any of the other players has just aquired trade. the answer is usually "yes". There are other techs that trigger the same thing later, but I haven't verified which ones yet.

Rich

[samson]

Rah,

I believe there are distinct 'causative' and 'trigger' events involved here that may explain what you have observed.

A 'causative' event is one which changes one of the base factors on which the supply/demand of a city is calculated. Possibly: city size, terrain, # of techs. But the change in supply/demand does not become visible until a 'trigger' event occurs.

A 'trigger' event is one directly related to the Trade system: delivery, production, or receipt of a caravan or, possibly, the use of the Trade Advisor to investigate supply/demand.

If this hypothesis is true, then the acquistion of Trade by your opponents and their immediate use of the Trade Advisor to gain intelligence about foreign cities, would explain why you see updates to the supply/demand of your cities on the same turn. The changes to supply/demand were latent, but unmanifest, caused ultimately by other factors, but made visible by an opponents discovery of Trade.

[rah]

It happened once, when I was the first to trade. When the second civ got trade, I saw one change that turn while looking at it. He had not built a cavaran yet, and had not checked the demand advisor, So just him getting trade triggered it.

RIch

[samson]

Okay.
The cause/trigger hypothesis still holds though. Acquiring Trade must update the supply/demand displays of cities immediately, making any latent changes appear.

I'm not saying this is how it works, mind you, just a theory to be investigated. I'll test it out some.

[rah]

Agreed. Testing is always good. There are so many factors sometimes that it's hard to isolate every piece.

[Scouse Gits]

Trade Testing

The 2.42 Deity/Hordes/Large World game below has a trade start at 4000BC so allowing commodity monitoring from the outset.

Try building a capital on different tiles and see the variation in supply and demand.

-------------------------

SG(2)

[Elephant]

solo, you are my kinda person! Your first post on the 16th at 13:53 was pretty meaty, but you must have kept on plugging all day cause your second post at 20:30 was filet minion!

samson, I'm trying to work on the commodity supply/demand changes, and what you commented was right along things I am suspecting. There seems to be either a GameTurn or TechNumber component, and there also seems to be either a CivilizationNumber or ContinentNumber component as well. There seem to be "trigger" techs for the two highest commodities, oil and uranium. The city size trigger is a new one for me, so I'll have to go back and retry some test games to see if that affects the changes. There is definitely a repeating nature to some cities, and it seems to be initially indicated by Hides being one of the three. I have not played enough tests to verify, but it seems at some point a repeating demand can be satisfied. Perhaps a random number is generated as to how many repeaters are accepted? And there is the whole issue of reciprocal trade, that when a demanded caravan is delivered from city A to city B, one of city A's demands may be satisfied at the same time.

I wish I could spend as much time on this as solo!

[solo]

My internet connection has been down for a few days, which may be a good thing, since I like to jump to conclusions based on little or flimsy evidence!

So I now have a few corrections to some previous observations.

1) The city sizes of 7, 10 and 13 are not magical numbers, but very often a change in city size causes a re-supply to occur. However, once re-supply starts at one size, a change is likely to occur when the city gains another 3 citizens, and again after another 3, since I have just seen a consistent pattern in many tests between just two cities, with supply changes occurring at sizes 5, 8 and 11.

2) Previously, I believed that re-supply could only be triggered by using up a caravan, but this is not always the case. As I have seen by altering city sizes, sometimes just doing this is enough to act as a trigger. As samson indicated, there definitely seem to be different trigger events. rah's experience confirms this, as one would expect the discovery of Trade by another civ to be a significant event, likely to cause changes in the supply mechanism.

3) Sadly, and I say this because I, like samson, was looking for an underlying set of firm rules governing commodity supply; I have seen some strange things occur, but in spite of duplicating the exact same conditions (as far as I could see), I could not repeat certain re-supply events. However, even though there is some sort of random factor involved, I still am seeing certain repeatable patterns, and enough of them to be encouraged to conclude that the random effect may be minimal.

4) Since the variables (including some chance) that have an effect on re-supply are hard to isolate, it is hard to know how to set up tests that duplicate enough of the vital game conditions to produce reliable information. So when reporting further "results", I will provide the parameters that were in effect while conducting them. For example, in my tests so far, I have been changing city sizes with the cheat menu to save time, after an initial run where I allowed cities to grow naturally, as they would in an actual game.

5) While playing a bit with terrain changes in cheat mode, I noticed that changing terrain often changes one of the commodities on the supply list. I fooled with this for enough minutes to conclude that figuring out how it actually works might become another major project! However, if terraforming were to allow one to secure the most valuable supply commodities, it would be worth knowing what to tell your engineers to do.

6) Previously I noted that hides would rob a supply from a target city when delivered, but this is not a special property of hides, since all commodities do the same thing. This may help explain why the AI hardly ever trades commodities. Their cities are robbed of another supply for every cargo delivered by the human player. I'm guessing that by the time they can trade actively, many of their cities can only make food. The AI also like to use the caravans that they do bother to make for scouting purposes or as lookouts on isolated islets! They seem to be programmed to disregard trade as a proftiable activity.

7) Currently, I am testing a small two-city trading system, to see what happens before any of the AI know or are involved in Trade. I'm hoping that simple tests in a small, closed system can reveal some useful info, which I hope to add in my next post here.

[solo]

I think some definitions are in order, to avoid confusion in results being reported by different testers, as I see that others are looking into certain aspects of this fascinating topic:

1) A supply will be defined as a commodity in a city’s supply list not surrounded by parentheses, in other words, a commodity other than food that can be assigned to a new caravan or freight.

2) A trigger will be defined as an event that reveals a new supply in a city.

3) A cause will be defined as an event that enables, but may not reveal, a new supply in a city.

4) An enabled city will be defined as one having a new supply due to a cause, but not yet revealed by a trigger.

5) A block will be defined as an event that reduces the number of supplies in a city. For example, a delivery of a commodity to a city having supplies, often ends up blocking one of them. A block results in a set of parenthesis being put around a commodity in a city that was previously in supply. Just the act of building a commodity caravan or freight, is another example of a block.

In limited testing so far, I have noticed some events seem to combine the functions of a cause and a trigger. Also, some events may act as causes in certain situations and as triggers in others. Maybe these events should get special names, too, but for now, 5 definitions are probably plenty!

I have finished a round of testing the effects of city size changes and will post the results when they are ready.


Elephant,

Welcome, and good to see another contributer!

Number of turns and techs are bound to be involved, I think. Oil and Uranium certainly seem to be tech dependent, as I have never seen either before freights are available. In my tests so far, I have seen many cases of what I will now define as alternating supply. For example, a city may supply just gold, but after that is built and delivered, dye may become available, which when built and delivered frees up a new supply of gold. Of course, alternating supply can be vary lucrative, so finding ways to initiate and sustain it would become quite valuable.

[Scouse Gits]

solo...well done. Trade and Huts are the final frontiers of understanding the game. You have started to channel our thinking about trade ... and Civ 2 will shortly be 7 years old!

I want you to succeed but at the same time I want you to fail. Once the secrets of the mysterious lady are all revealed…who will worship her? (From a founder member of the GL )

------------------------------

SG(2)

[Elephant]

Solo - are you investigating reciprocal trade routes, where the delivery of a commodity from City A demanded by City B causes one of the demands of City A to be "satisfied" (parenthesied?) by something supplied by City B?

[solo]

Not yet, but I have already noticed an example of this after making my first trade in one test. It is definitely one aspect of trading that has to be looked into, if we are going to solve the whole puzzle.

What about yourself? Looking into anything specific? If so, we might save time by not duplicating the efforts of others.

Right now, I'm concentrating of changes due to city size, and how this relates to the sequence of trades being made.

[solo]

TEST #1 of the effect of city size on supply when trading between two American cities.

The setup:

After a random start, the two American settlers founded Washington and New York. Then the cheat menu was invoked to make some changes to facilitate testing. The entire map was revealed, so AI tech progress could be monitored. The Americans were given 29,000 gold in order to rush buy caravans and other items that were needed. The Americans were given Trade and the techs leading up to it. Much of the terrain around the two cities was changed to grassland and was irrigated, to promote rapid city growth. The two cities were connected by a road. The government type was set to Fundamentalism to deal with unhappiness. Both cities were fortified by creating a few phalanxes.

Supply and demand started as follows:

Washington
Supplies: dye, salt, copper
Demands: hides, beads, wine

New York
Supplies: dye, wine, gems
Demands: hides, silver, wool

This starting position was saved.

This test involved several passes, in order to investigate the effects of different trading sequences as the cities grew in size. During the first pass, the cities were allowed to grow naturally, as they would in an actual game. When cities were not building caravans, wonders were used to accumulate shields. The only city improvements added were aqueducts, necessary to allow growth of both cities beyond size 8. After recording the results of this first pass, another pass was made in which the same actions were performed, the only difference being that city sizes were augmented using the cheat menu, instead of waiting for them to grow. The results of this pass were identical to those of the first, so for the remaining passes, the cheat menu was used to save time.

Each pass will be separated into events. If any supply or demand changes for either city were triggered by the event, they will be noted in boldface type.

Pass #1

Event #1 – Washington builds dye and delivers it to New York

Washington
Supplies: (dye), salt, copper
Demands: hides, beads, (wine)

New York
Supplies: dye, (wine), gems

Notice that the delivery of dye to New York, blocked its supply of wine.

Event #2 – Washington builds salt and delivers it to New York

Washington
Supplies: (dye), (salt), copper
Demands: hides, beads, wine

New York
Supplies: (dye), (wine), gems

Now New York’s supply of dye has been blocked by the delivery of salt.

Event #3 – Washington builds copper and delivers it to New York

Washington
Supplies: (dye), (salt), (copper)

New York
Supplies: (dye), (wine), (gems)

The third delivery of copper blocks the final supply of New York, gems. No commodities are in supply now, so city sizes will be augmented to see what happens. For now all caravans are being built in Washington and delivered to New York to keep things as simple as possible.

Event #4 – Washington and New York reach size 3

Washington
Demands: hides, wine, silk

New York
Demands: hides, silver, silk

Nothing happened when both cities went to size two, but there were demand changes for both when they got to size 3.

Event #5 – Washington reaches size 4

Washington
Demands: hides, wine, beads

Event #6 – New York reaches size 4

New York
Demands: hides, silver, beads

Demand changes are frequent as small cities change size, and these neighboring cities show they have a lot in common. Notice how new demands are appearing in the third spot, too. At this point, I decided to stagger city growth, so both wouldn’t change size on the same turn. This would make the effects of growth easier to pinpoint.

Event #7 – Washington reaches size 5

Washington
Supplies: (dye), (salt), gold
Demands: hides, wine, silver

Gold is the first new supply in Washington, triggered (and probably also caused) by the change from size 4 to size 5. Another demand change occurs, too. Note how the first new supply popped up in the third spot of the supply list.

Event #8 – Washington builds gold and delivers it to New York

Washington
Supplies: dye, (salt), (gold)

The delivery of gold to New York triggers the re-supply of dye. This is a surprise and the cause for this new supply of dye can not be determined yet. The following passes shed a little light on why this might have happened.

Event #9 - Washington builds dye and delivers it to New York

Washington
Supplies: (dye), (salt), gold

Gold is back in supply again! This turned out to be one of those desirable alternating supply situations, since events 8 and 9 were repeated many times before Washington reached size 8, at which time the gold-dye alternation ended. Having alternations of supply available as early as size 5 is very good news, especially if it turns out that they can be pre-arranged by carefully planned builds and trades.

Event #10 – New York reaches size 5

New York
Demands: hides, silver, gold

Another demand change, also appearing in the third column. It is interesting that it is demanding gold, which was the first new supply for Washington after Washington reached size 5, earlier.

Event #11 – Washington reaches size 6

Washington
Demands: hides, wine, silk

City size changes seem to affect demands the most.

Event #12 – New York reaches size 6

New York
Demands: hides, gold, silver

This is the first unusual demand change for New York. The two existing commodities on the list, gold and silver, just switched their positions. It is hard to know what such a different kind of change in demand signifies.

Event #13 – Washington reaches size 7

Washington
Demands: silk, wine, silver

Another departure from the usual. Hides, which lasted a long time in position 1 of the demand list, is finally supplanted by silk. At the same time silver, which has been dancing with gold in New York’s demand list, turns up in position 3, where silk used to be.

Event #14 – New York reaches size 7

New York
Demands: silk, silver, gold

All three positions change, and hides also is supplanted from New York’s demand list. Once again, silk is the hitman. Silver and gold flip again!

Event #15 – Washington reaches size 8

Washington
Supplies: (dye), (salt), wool
Demands: silk, hides, silver

With so many demand changes when the two cities reached size 7, I figured something new was up for when Washington grew to size 8, and sure enough, wool has appeared as a new supply in position 3, taking the place of gold. The gold and dye alternation has ended, too, which has been repeated every turn since it started, long ago.

Event #16 – Washington builds wool and delivers it to New York

Washington
Supplies: dye, (salt), (wool)

Delivering wool triggered another supply of dye, just like the gold delivery during event 8. Another alternation?

Event #17 – Washington builds dye and delivers it to New York

Washington
Supplies: (dye), (salt), wool

Yes, and this one worked just the way the previous one did, since events 16 and 17 were repeatable until Washington reached size 11, later on. Notice that once a new supply is first revealed, such as the first appearance of gold, something new to the supply situation occurs after the city grows by 3 more citizens. In this test, new supplies were introduced for Washington when it reached sizes 5, 8 and 11. Also noteworthy is the fact that all the supply action has been centered on Washington, so far, probably an effect of the simplified one-way trading adopted for this test. New York is yet to have a new supply, only changes in demand.

Event #18 – New York reaches size 8

I was expecting something big here, but nothing happened, not even the usual demand change! But in a way, no change at all is in itself a significant event, since demand changes came at every size change since the city had been at size 2.

Event #19 – Washington builds an aqueduct in order to go to size 9

Washington
Supplies: wine, (salt), gold
Demands: copper, dye, silver

Wholesale changes! No trades were made this turn, so the aqueduct must be the trigger. Maybe it is, but the effect was only temporary, because things went right back to the way they were the next turn when I built another caravan. This must be some sort of glitch about aqueducts, and after seeing this happen here, it reminded me of an OCC game where I noticed two “new” supplies after building an aqueduct. My poor OCC city had been stuck on food for awhile, so I jumped at the chance to build something else by rushing a caravan. The next turn only food was available! Well, to return to this test, a few turns later I built another aqueduct in New York, and the same thing happened: wholesale changes and even the first new supply for that city. However, after a caravan from Washington was delivered, the supplies and demands returned to their previous settings, making it another false alarm.

Event #20 - Washington grows to size 10

Washington
Demands: silk, silver, hides

Another demand change. No changes occurred when going from size 8 to size 9 earlier.

Event #21 – New York grows to size 10

New York
Demands: silk, gold, silver

Ditto.

Event 22 – Washington grows to size 11

Washington
Supplies: (dye), (salt), gold
Demands: silk, wine, hides

After three more citizens have been added the wool-dye alternation comes to an end. Gold comes back as the next new supply, which appears again in the third position. This supply change is accompanied by a change in demand, too.

Event 23 – Washington builds gold and delivers it to New York

Washington
Supplies: dye, (salt), (gold)

It looks like the gold-dye alteration is back again.

Event 24 – Washington builds dye and delivers it to New York

Washington
Supplies: (dye), (salt), gold

It is, and it does continue this way until New York reaches size 11. Events 23 and 24 are repeatable, setting in motion the third cycle of alternating supply.

Event 25 – New York grows to size 11

New York:
Supplies: (dye), (wine), cloth

Well, well, well! New York gets its first new supply, which is cloth. At this time, I decided to break from one-way trading and built a caravan in New York, as well as the usual one in Washington.

Event 26 – Washington builds a dye and delivers it to New York and New York builds a cloth and delivers it to Washington right afterwards.

Washington
Supplies: (dye), (salt), gold

New York
Supplies: (dye), wine, (cloth)

Washington’s gold-dye alteration continues and what turned out to be New York’s cloth-wine alternation begins. A very nifty dual alternation came into being. However, this relationship was quite fragile, since the sequence of deliveries on following turns did have an effect on re-supply, in some cases causing a block to one of the alternations, and in some cases re-supplying the same commodity two or more times in a row. In the future, I plan to test for the optimal sequence of deliveries, to make the most out of this dynamic of dual alternation. I concluded pass #1 of the first test here.

The next step was to try and repeat pass #1 using the cheat menu to speed up the process of changing city sizes. This worked, with duplicate results. In fact, I found out two more things while changing city sizes this way. One, was that aqueducts were not needed for sizes above 8 when cheating. Two, it was possible to skip over sizes where events had occurred that had changed demand or supply, yet duplicate the supply and demand situation for a city at the size selected. For example, after Washington had delivered it first three caravans, I could immediately set its size to 5 and observe the identical supply and demand lists I had seen after an orderly progression through intervening sizes. I found that I could even go back to a previous city size, causing a reset to occur of the supply and demand lists originally observed at that size! It appears that the link between city sizes and these lists is a very strong one, and possibly city size is the primary cause of these changes, and that all other events simply function as triggers. If this turns out to be true, testing will be simplified quite a bit.

Since this post is now quite lengthy and was promised a few days ago, I will terminate it here. The five remaining passes of the first test will be summarized in the next post.

[samson]

Solo,

You should be aware that revealing the map via the cheat menu very often changes the supply and demand of cities. This may invalidate some of your testing.

[solo]

samson,

That is very possible, and I will be trying an actual game next in an attempt to duplicate the alternations observed in this test, by attempting the same sequence of trades. Even more than revealing the map, I'm afraid that my terrain changes might be another source of trouble. We shall see.

If the test are only partially valid, they may still reveal some of the underlying mechanisms at work governing supply and demand. Further results of this test follow:


TEST #1: Additional passes

Five more passes were made, to test the different sequences of the opening three trades. Only the events where changes occurred will be noted:

Pass #2

As in pass #1, Washington built a dye caravan first and delivered it to New York, but switched the order of the following two builds and deliveries:

Event #2 – Washington builds copper and delivers it to New York

Washington
Supplies: (dye), salt, (copper)

Event #3 – Washington builds salt and delivers it to New York

Washington
Supplies: (dye), (salt), (copper)

This switch did not produce any changes in supply or demand during all of the following events. Results were identical to those of the first pass.

Pass #3

This time the sequence started with salt:

Event #1 – Washington builds salt and delivers it to New York

Washington
Supplies: dye, (salt), copper

Event #2 – Washington builds dye and delivers it to New York

Washington
Supplies: (dye), (salt), copper

Copper was built and delivered last, with the same results as in the first pass.

Event #8 – Washington builds gold and delivers it to New York

Washington
Supplies: (dye), salt, (gold)

A new supply of salt is triggered rather than a supply of dye as in the first two passes.

Event #9 – Washington builds salt and delivers it to New York

Washington
Supplies: (dye), (salt), gold

As in the first and second passes, an alternation of supply begins, but this time it is between gold and salt instead of between gold and dye. Similarly, salt took the place of dye in following events initiating a wool-salt alternation at size 8 and another gold-salt alternation at size 11. However, there were not any changes to any of the events causing a change in demand or to event #25, when New York went to size 11.

Pass #4

This sequence also started with salt, but copper was built and delivered during event #2 and dye came last in event #3. The remaining events produced the same changes in supply and demand that occurred during Pass #3. Again the three alternations featured salt instead of dye, when Washington went to sizes 5, 8, and 11.

Pass #5

Event #1 – Washington builds copper and delivers it to New York

Washington
Supplies: dye, salt (copper)

Event #2 – Washington builds dye and delivers it to New York

Washington
Supplies: (dye), salt, (copper)

Event #3 – Washington builds salt and delivers it to New York

Washington
Supplies: (dye), (salt), (copper)

Now it’s copper’s turn to go first, and if things happen the same way, one would be expecting copper to have its turn in the three alternations that follow, but that did not happen.

Event #8 – Washington builds gold and delivers it to New York

Washington
Supplies: (dye), (salt), (gold)

That was it. One gold delivery and no alternation at all. The same thing happened for Washington, when wool came into supply during Event #16. After the first wool caravan was built and delivered, all of Washington’s supplies became blocked. Ditto at Event #22 when gold returned. So instead of 3 sets of alternations at city sizes 5, 8 and 11, Washington only produced 3 single trades. New York’s alternation of cloth and wine, beginning later at event #25 was not effected, though.

Pass #6

The last opening sequence was tested in this pass, with gems leading the way in Event #1, followed by salt second and dye coming last. As expected, results were identical to those of pass #5. A likely explanation for the failure of Passes 5 and 6 to produce alternations is the fact that the new supplies of gold, wool, and gold at sizes 5, 8 and 11 all appeared in the third position of Washington’s supply list, removing gems from the picture and blocking it as the alternation partner. If it’s not there, it can not participate.

The results from these 6 passes suggest a few tentative conclusions and/or trading rules regarding supply and demand:

1) Changes in city size can cause changes in commodity supply. Once a new supply occurs, another can be expected when the city grows by 3 more citizens, and then another when an additional 3 citizens have been added.

2) Changes in city size can cause and trigger changes in demand.

3) The sequence of early trades is important in determining whether alternations become available later on.

4) The commodity chosen for the first trade will be the alternation partner for the first new supply.

5) New supplies or demands tend to appear in the third position of their lists.

6) Trade one of the commodities in position 1 or 2 of the supply list before the one appearing in the third position.

More testing will follow, the next logical choice being to make another 6 passes, but switching the roles of the two cities. There was enough consistency observed during the first six passes to predict exactly what will happen, but at this time it might be helpful to make use of the excellent start provided by SG, and play a real game using it, in an attempt to duplicate the alternations observed during this test, by attempting the same sequence of trades.

[Scouse Gits]

Wow ... solo, impressive testing and excellent posts.

Some time ago when there was a discussion on cities with a repeating Hides supply, I recall Xin saying that you should never use Hides as your first choice for a trade route. The order in picking the commodities does seem important.

Most of my civ is on large worlds and I have found it important to keep building new cities throughout the game as the new ones are often suppliers of prized commodities like Silk/Oil/Uranium.

As humans we take great care to found our cities using the maxiumum number of specials available...unlike the AI that builds one tile off the optimum site. When such cities have been captured I have noticed that their supply of commodities seems better than the "perfect" human cities. Initially this is down to the fact that the AI does not build freights as often as humans, but after establishing three routes the commodities (both supply and demand) can appear more plentiful. Perhaps there is some inverse relationship between terrain specials and supply/demand commodities?

--------------------

SG(2)

[samson]

The delivery of gold to New York triggers the re-supply of dye. This is a surprise and the cause for this new supply of dye can not be determined yet.

It's because you've replaced an existing trade route and thus freed up Dye. Your post does not include the trade-routes information which is critical to understanding the resupply phenomenon. See Xin Yu's post on resupply in the GL. As I mentioned in the commentary on my 16AD game, continual commodity availability hinges on getting a fourth commodity in a timely fashion and using this to replace an existing trade route. Once you've got this set up correctly, you can go on almost indefinitely, resupplying and delivering caravans to a partner city. It gets more complicated with multiple cities and when switching from one trading partner to another.

[solo]

samson,

You are right about the trade route info being important and thanks for pointing out how re-supply occurs when replacing an existing route with the delivery of a newly supplied commodity. I failed to make that connection, but I did keep track of trade route changes and will provide a summary here, since I did omit doing so in the original posts:

The first three deliveries in each pass created the three initial trade routes for each city, with the routes appearing in the order of commodity deliveries. During my tests only the first trade route in Washington was replaced by the delivery of the new commodities during events 8, 16 and and 23, when the deliveries of gold, wool and gold replaced the trade routes initally created by dye in passes 1 and 2, salt in passes 3 and 4, and copper in passes 5 and 6. Similarly, the new supply of cloth appearing in New York during event 25, supplanted the original trade route created when wine was blocked (and selected for trade route #1 in New York) by event #1 deliveries.

During alternations, whatever had been delivered last took up residence as Washington's first trade route, freeing up another supply of its alternating partner, which when delivered would be listed as the first trade route, after which the alternation continued until interrupted by another event. I should also clarify that after event #3, all deliveries from Washington to New York only changed Washington's first trade route. New York's first trade route did not change until it event 26, when it built cloth and delivered it to Washingtron.

SG,

I am still very tentative about what was observed during the first test. Samson's point is well taken. Any use of the cheat menu, when conducting tests may very well taint the results with invalid information.

Thanks again, for providing that start with Trade. I'll get started with that test game.

solo

[Elephant]

Solo, are you experimenting with the ORDER in which you build caravans (esp if Hides is first), and the ORDER in which you deliver them? There might be something there...

I am (trying to!) work on how a city's initial three commodity options are determined, and what events trigger or cause changes to those commodity options. There are both demand and supply issues involved, and I have noticed reciprocal trade routes pop up at wierd times. I am pretty sure there is a random component to some of this (from saved game restarts) but there is the element of what the other civs are doing that I am not aware of. Samsons post about cheat mode changing things made me go back and reconsider some things that happened in tests where I used Cheat to get Trade early or "gift" some settlers. I'm trying to run some basic "honest" games with multiple saves and restarts, duplicating moves and logging commodity lists. Lots of documentation! Looks like you are having fun too...

[samson]

Re: CHEAT MODE.

Specifically what I have seen is that using the cheat menu's Reveal Map command often causes changes in supply and demand in many, if not all, cities. This may in itself be a clue about what factors affect the commodities a city supplies. However, until this effect is better understood, be cautious about drawing conclusions from tests using this feature.

[solo]

Elephant,

I am investigating the effects of city size in conjunction with the order of commodity deliveries.

In my current game, using SG's start with Trade, I am playing "honestly", and probably long enough now to conclude that supply and demand changes do NOT follow the patterns I observed earlier in tests using cheat mode. For example, so far in my game, no supply or demand changes have occurred yet, during the turns that cities changed their size. This happened very often with the cheat mode tests. With one city at size 8 now, and the other at size 5, all of my supply and demand changes in this "honest" game have come on other turns, instead.

However, I have confirmed in one case of re-supply, that this could be postponed by going back to a previous save, and making changes that delayed the growth of the city in question.

So for now I'm just sticking with "honest" games, saving them every turn, and using reloads and partial replays to test the effects of any changes.

My plan now is to start another game using MGE, using the hotseat feature so that I can play and observe every civ, and hopefully learn more about the trade mechanism by "knowing" what everyone is doing.

[Elephant]

I was suspecting something with the Cheat mode/Reveal Map, but had not done enough direct comparison yet. Tossed a pile of logs after realizing that one. Sigh.

Perhaps there is an element to how many times a particular cities is "checked", like a random number that says "if anyone checks the city X number of times, through Trade Advisor or whatever, trigger a commodity change"? That would be sneaky!

[solo]

Test with a civ having Trade at the start

Using the start provided by SG, I built just two cities, in an attempt to mimic the events in the test where cheat mode was used to manipulate events quickly.

At first, city growth was purposely held back a bit, so that London had time to build and deliver three caravans, of silk, dye and cloth to York, which resulted in the following trade displays for the two cities:

London

Supplies: (silk), (dye), (cloth)
Demands: hides, silver, wine
York silk +0t
York dye +0t
York cloth +0t

York

Supplies: (silk), (gems), (dye)
Demands: hides, wines, beads
London gems +0t
London silk +0t
London dye +0t

This was all done before either city reached size 3. So far, events were similar to those of the first pass of the first test in cheat mode, with all supplies exhausted and with all three trade routes for both cities established.

Shortly after, both cities reached size 3, with London doing it first. At this point, similarities to the cheat mode test ended, since no changes in demand or supply occurred.

So the game continued, letting the two cities continue to grow. A few turns after London grew to size 4, it had a change in demand:

Demands: hides, silver, beads

Beads replaced wine on London’s demand list, appearing in the third position of the list. The appearance of new commodities in the third position of lists was also observed repeatedly in the cheat mode test. England’s cities were not in the best locations for growth, so many turns went by before London reached size 5. One unusual event noted during this period was that York’s trade picture changed temporarily, since after it built a temple, I zoomed to York, and observed:

York

Supplies: (silk), (gems), salt
Demands: dye, hides, wine
London gems +0t
London silk +0t
London dye +0t

A new supply of salt and a complete change to the demand list seemed to occur. However, as in building an aqueduct, in the cheat mode test, this was only an illusory change, since things returned to their former state immediately upon re-entering York’s city window. Since I had been saving the game after each turn, I decided to go back and change my build from a temple to a barracks, just to see if the same thing would happen, and it did. I wish I had had a dye or wine caravan nearby, to see what would have happened demand-wise, if I had attempted to deliver it before re-opening York’s city display. Would the commodity have been in demand, and would this delivery have altered York’s trade situation?

In any event, the game continued, and while exploring with a diplomat and a trireme, I happened to trigger an advanced tribe from a hut shortly after London reached size 5. This new city, Nottingham displayed:

Supplies: beads, silk, hides
Demands: wool, wine, gems

Though nothing was happening with London or York, the next turn brought some changes to Nottingham’s display:

Supplies: beads, gems, hides
Demands: wool, wine, dye

Shortly after this, the Zulu’s declared war and destroyed Nottingham with an elephant. In the meantime, York was able to complete Marco Polo’s, which provided information about the other civs. At this point, I noticed that none of them had acquired trade yet.

Finally, a few turns before York turned size 4, a new supply appeared, which was salt:

Supplies: (silk), (gems), salt

As in the cheat mode the new supply appeared in the third position of the list, but this time it was the city that received the 3 initial caravans getting a new supply first, rather than the city that had done the initial building and delivery. It was interesting to see that salt was the same new supply as had appeared in the false change in the York’s trade picture when York completed its temple earlier in the game. However the demand list did not change, as in the earlier event.

With nothing better to do at this point, York built a salt caravan and delivered it to London, changing York’s display as follows:

Supplies: (silk), gems, spice
Demands: hides, wine, gold
London salt +0t
London silk +0t
London dye +0t

No changes occurred for London. As expected, the delivery of salt released gems from trade route number 1, creating a re-supply. Spice appeared in the third position of the supply list, replacing salt. A demand change also occurred, with gold replacing beads.

At this point, an alternating supply situation was available, since if a gems were built and delivered next, it would replace salt in the first trade route. Then spice could be built and delivered, triggering another re-supply of gems. So a gems caravan was built next.

In the meantime, London had completed an aqueduct, which produced another false display when I zoomed to the city:

Supplies: (silk), beads, gold
Demands: dye, silver, hides

Again, many changes that disappeared just as soon as I re-examined the city. One interesting thing of note, is that this had NOT happened when London built a temple, so I was left to wonder why and when this weirdness happens, since I had been careful to use the “zoom” option after every building had been completed. How come York’s temple (or barracks) made this happen, earlier, when nothing changed when London built its own temple?

To continue, after York built gems and delivered it to London, the alternation was established between spice and gems:

Supplies: (silk), (gems), spice
Demands: hides, wine, gold
London gems +0t
London silk +0t
London dye +0t

After this the first spice caravan was built and delivered to London, and a few turns later the following changes appeared in London:

Supplies: (dye), beads, gold
Demands: hides, silver, wine
York silk +0t
York dye +0t
York cloth +0t

Note how the new supplies of beads and gold were “previewed” by the false display after London’s aqueduct was built, just as York’s false display of salt after building a temple was “confirmed” later when salt actually appeared. This may end up being just a coincidence, but may also become a useful predictive tool of the future supply situation of any city.

Anyways, by this time, London had reached size 7 and York was still at size 4. Once the beads and gold became available in London, both cities were able to sustain alternating supply for as long as this test was continued. I decided to stop in 1650 AD, many turns later. This was a very desirable situation, but early growth had been so slow, that the game was already well into the AD years by the time this dynamic relationship got going. By this time, the English were solidly in last place in most other aspects of the game!

Before abandoning this game, I decided to try a few replays to see if playing differently would influence how the appearance of new supplies worked. London’s supplies had been blocked until the year 740 AD, when beads and gold appeared shortly after a delivery of the first spice caravan from York. I tried a lot of different things in replays, such as different builds, or different timing of caravan deliveries from York, but beads and gold always showed up in London in 740 AD. Finally, I went back far enough, back to the year 560 or so, where I was able to delay the growth of London to size 7, which had originally occurred in 600 AD. I delayed this event by about 5 turns, and sure enough, this resulted in the delay of the appearance of beads and gold. I was also able to cause a further delay by purposely postponing the delivery of gems from York to London, during one of the replays delaying London's growth to size 7.

So, although this test did not confirm any of the seemingly direct and/or immediate affects city size changes and caravan deliveries were producing in cheat mode tests, these replays do suggest that city growth and timely deliveries are necessary to obtain new supplies. Since it also took a very long time for supply and demand changes to appear in this game, it may be perhaps be surmised that this was due to the slow growth England experienced.

Some other similarities observed with the previous cheat mode tests were in how new commodities appeared on the supply and demand lists, after the first three trades. In both tests, the city getting the first new supply was able to begin an alternating cycle as long as the initial trades were made in one of the “right” orders. In addition, when a new supply finally appeared for the other city, a dual alternation was set up between the two cities.

At this point, I am trying an MGE hotseat game, where I am playing all the civs, and can observe all the supplies and demands that are in effect. Keeping track of these, as they gradually change, will be a bit time-consuming, since I’m hoping to record all events, in an attempt to isolate which are significant, and which are not. This may end up being like those high score record attempt games, i.e. endless, so I’m hoping samson solves all of this within the next few days, so I can get back to having some fun, which is just playing this game.