How Supply and Demand Lists Are Determined

[SCG]

My research wasn't quite so involved I was looking for a diety game with cities that were actually supporting units, so i would be able to lower the production to 0. If a city has no support, it will always have extra production from the city square itself. The fact that copper was there provided optimism, although Rome also has Copper and nothing happens there.

[SCG]

as a followup, i'm wondering if the turns where this happen correspond with the 16-year cycles discussed earlier. If so, perhaps Rome will display similar results sometime in the next 15 turns?

[SCG]

another followup = Rome does do the same thing in 1323. Uranium -> Dye on demand list, and Gold->Wool on the supply side

[SCG]

one more followup - the phenomenom occurs again in Ravenna in 1336 -> 16 turns later. Also, Rome recurs in 1339, also 16 turns later. I didn't run through every city, but did happen to notice that it occurs at Cumae (also with copper in the commodities list) in 1335. that may be the next test i run. One other note, rehoming a unit in that city will trigger just the same as removing a worker - key seems to be 0 production, and quite possibly recurs every 16 turns.

[solo]

SCG,

I'm betting your screen shots from Parkersburg came while playing the game in MGE, since I get a different result with the same city using 2.42

It looks to me that with MGE, manipulating shields triggers the dye bug and in 2.42 it's copper instead. In all examples I've seen so far, the result is copper or dye in the #1 demand slot. I believe other changes are due to a movement of copper or dye. I already know that the dye bug affects the human cities in MGE and the AI cities in 2.42, and examples so far of shields <=0 correlate with this difference.

I have also confirmed this works in deity.

goape,

Perhaps an example calculation for the supply of hides will help:

Suppose your city has a silk, 2 other forest tiles, 3 tiles with rivers and 1 jungle tile. Suppose that there are not any tundra or glacier tiles. Let's also assume that you have acquired 17 techs so far in the game and that the size of this city is 2.

First count up the total number of tile types relevant to hides:

forest = 4 for silk + 2 others for a total of 6.
rivers = 3
jungle = 1

Now using the first part of the formula:

Supply = 6x4 + 0x6 + 0x6 + 1x3 + 3x3
= 24 + 0 + 0 + 3 + 9
= 36

Now make the adjustment for having 17 techs, which is in the group of 16-23:

36x2 = 72

Now let's adjust for size 2:

72x2 = 144, which is the SQ for hides.

Notice how the SQ for hides will drop if the city grows bigger and as you acquire more techs. For example, when the city reaches size 8 we will divide by 2 rather than multiply by 2 when performing the last calculation.

SCG,

attached is Parkersburg after 0 shields in 2.42:

[SCG]

Originally posted by solo
SCG,

I'm betting your screen shots from Parkersburg came while playing the game in MGE, since I get a different result with the same city using 2.42

It looks to me that with MGE, manipulating shields triggers the dye bug and in 2.42 it's copper instead. In all examples I've seen so far, the result is copper or dye in the #1 demand slot. I believe other changes are due to a movement of copper or dye. I already know that the dye bug affects the human cities in MGE and the AI cities in 2.42, and examples so far of shields <=0 correlate with this difference.
SCG,

attached is Parkersburg after 0 shields in 2.42:

Originally posted by SCG
While trying to maximize the bonus value on a gold caravan between 2 of my cities, i was moving around the workers in the destination city. When the destination city had resources available for production, it supplied beads, salt and dye and demanded hydes, wine and gold. However, when i started moving all the workers onto sea squares, production resources dropped to 0 and then deficit. When it hit 0, the trade commodities switched around to supplies beads, salt and wine, and demands copper, dyes and hydes. putting the workers back took it back to the original supply and demand.

i think the various patches affect it. in my original post (above), I also got the copper, dye and hides. it may well have been from 1.07, which was what i played on a lot back then. however, I did not get any results with either Parkersburg or Fairmont with my MGE version.

attatched is proof it was 2.42.

[SCG]

Originally posted by SCG
i think the various patches affect it. in my original post (above), I also got the copper, dye and hides. it may well have been from 1.07, which was what i played on a lot back then. however, I did not get any results with either Parkersburg or Fairmont with my MGE version.

has to be something else affecting it besides patches

[solo]

SCG,

Yes, it's still a mystery why its dye rather than copper. I can not get it to happen to dye yet, so can not tell why.

However, I've also checked saves for other years, and it looks like you're right about this happening on city cycle turns. I also can not change back on turns that follow.

This is a nice piece of work by you, and it comes in time to be included in my EL guide, where you'll be credited with the discovery. Shall we immortalize this exploit as the "SCG switch"?

[SCG]

SCG switch has a nice ring to it

for one last followup, here's the MGE screen

[Scouse Gits]

Originally posted by SCG
SCG switch has a nice ring to it

Yeah ... I like that too. Just shows that there are still things to learn.

BTW does the switch have an "off" position?

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

SG(2)

[goape]

Solo,

Thank you for the explanation. As I have said, I am not the worlds fastest learner but thanks for replying to my question anyway. With this knowledge on the inner workings of supply and demand I hope to improve my game plan significantly. These forums truely are a wealth of knowledge.

[solo]

goape,

Don't forget to check out our Great Library, put together by Scouse Gits. Some of the best info about Civ II can be found there.

[Scouse Gits]

Originally posted by goape
Solo,
These forums truely are a wealth of knowledge.

Very true. Just when you think you know most of it - something else pops up.

When you are ready please join us in a succession game over on the Civ2 general forum. It seems very serious ... it's just big kids playing games really.

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

SG(2)

[Bloody Monk]

I am wondering if I understand this correctly. Please comment.

1) In 2.42, the dye/copper bug is blocked when you open the city screen on the solo cycle turn. It causes the "huge" numbers to correct.

2)If, as part of viewing the city screen, you also reduce shields to zero or less, then, this re-triggers the bug and alters the demand list (and the supply list if copper is present as it gets bumped).

I loaded the 1300 save before the Ravenna example of 1320 mentioned by SCG. The supply/demand lists are the same in both turns. This means (I think) that I must have viewed the city during the 1320 solocycle turn, and this corrected the bug.

Checking SCG's idea: Reducing the 1300 turn Ravenna to zero shields has no effect on the S/D lists. Also, I got different results in the 1320 change than that reported by SCG, if I am understanding his post correctly.
(cloth),(copper), (salt)--uranium,coal, silk became
(cloth), oil, (salt)---------copper,silk,dye

Which is ALSO what happens if I reload 1300, click enter, and then do not view Ravenna during1320. 1321 then has the same "new" list that I got doing the SCG switch.

Therefore, I believe the SCG switch is unnecessary IF you do not look at the city during it's solo cycle turn. Some testing might show circumstances where results are different, depending on what the original S/D lists are.

Now, since our method of playing results in many city views for micromanagement, especially changing/ maxing arrows before delivery, it becomes clear how important it is to keep track of the solocycle for each city. Doing this will open up blocked or fruitless S/D lists.

Monk

[SCG]

Originally posted by Bloody Monk
I am wondering if I understand this correctly. Please comment.

1) In 2.42, the dye/copper bug is blocked when you open the city screen on the solo cycle turn. It causes the "huge" numbers to correct.

2)If, as part of viewing the city screen, you also reduce shields to zero or less, then, this re-triggers the bug and alters the demand list (and the supply list if copper is present as it gets bumped).

That sounds about right

I did a couple more tests, this time on computers running Civ 2.42, but before and after MGE was installed - Even though i installed MGE in a different directory, it still seems to have affected the way it determines supply and demand.

Ravenna 1320ad

Civ II 2.42, without MGE installed (Pentium, win95)
production >0
supply: (cloth) (Copper) (salt)
demand: Uranium Coal Silk

Production <=0
supply: (Copper) Oil (Salt)
demand: Copper Silk Uranium

Civ II 2.42, with MGE installed (Pentium IV, Win ME)
production >0
Supply: Beads Wine (Salt)
Demand: Uranium Hides Dye

Production <=0
supply: Beads Wine (Salt)
demand: Dye Hides Coal


For further research, i reduced Ravenna to 1 shield production in the after version, then went into cheat mode and created another unit supported by Ravenna without opening the city screen, and checked the supply/demand list. Uranium was still demanded, but once i opened the city screen, it was changed to Dye.

[Bloody Monk]

@SCG

I find it very strange that you get a different demand list in 242<0, example. Does the game act differently under differing operating systems--I use WinXPhome. I also have MPGE in a different directory.

Monk

[SCG]

Originally posted by Bloody Monk
@SCG

I find it very strange that you get a different demand list in 242<0, example. Does the game act differently under differing operating systems--I use WinXPhome. I also have MPGE in a different directory.

Monk

Based on the directory that the saves leading up to jo_a200.sav are located in and the time stamps, and my original thread, i originally had different supply/demand lists for 2.42 on a windows ME install pre MGE than i do now post MGE install, but still running the 2.42 game. So, i would say that it is not OS dependant. (I've only had MGE since the end of january, and my thread was from 20 months ago). I don't have enough room to install MGE on my old computer atm, but i may test that out later to be sure. I do find it rather puzzling, even if i now know how to duplicate it now.

[Bloody Monk]

Well, I was detailing the different results I got on my box with XP compared to the results you got using another OS. This with both of us using a save from my box to generate these differing results.

One would suppose that a save "ought" to generate the same results on two boxes using the same version of the game. Otherwise, why post saves at all??

It means to me that some random factor is yet to be discovered.

Monk

[SCG]

Ok, this is a little confusing. I installed MGE on my old computer (can't play it though till i install a working CD drive on that one - it doesn't like reading the CD from a network drive when playing), and then loaded ca_a1320.sav back in the 2.42 version. Results are unchanged from before the installation. I then reinstalled 2.42 on the new computer. Now both the old and new copies of 2.42 on the ME machine give results more (but not completely) consistant with the installation on the win95 machine. the old and new copies of 2.42 have the same timestamp and size. (I copied the 2.42 and called it civ2242 before reinstall so wasn't copied over) However, the civ2107.exe still gives the altered commodities (running in the same directory so reading from the same files). Looks like i may have had multiple minutely corrupted files.

Incedentally, MGE still gives different commodities than all 3 of the 2.42 versions and the (corrupted?) 1.07 version

MGE
supply: (Cloth) Oil (Salt)
demand: Copper Silk Uranium

2.42 (ME reinstall)
supply: (Cloth) (Copper) (Salt)
demand: Uranium Coal Silk => Dye Silk Coal

1.07c
supply: Beads Wine (Salt)
demand: Uranium Hides Dye => Dye Hides Uranium (reorder, but no change)

2.42 (95 install)
supply: (Cloth) (Copper) (Salt) => (Copper) Oil (Salt)
demand: Uranium Coal Silk => Copper Silk Uranium

(corrupted?) 2.42 and 1.07
Supply: Beads Wine (Salt)
Demand: Uranium Hides Dye => Dye Hides Coal

also, from the 2.42 patch.txt under the changes for version 1.11:
* The Supply/Demand equation for commodities has been revised somewhat.

Is the game is consistant every time in choosing between wildcards when there are 3 to choose from (including oil and uranium)? If it isn't, that might explain the remaining variation? Otherwise, I may need to uninstall and reinstall my 2.42 version instead of install over...

[Scouse Gits]

The Bread Wonder Trick is useful for releasing new commodities in a large city. However, I didn't know that it works in reverse! Playing the second Early Landing Comparison Game I completed a caravan in the SSC where the wonder was to be built. When I placed the caravan back into the city to "help build the wonder" it blocked my supply commodities.

Is this well know or have I missed something ?

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

SG(2)

[Bloody Monk]

Originally posted by Scouse Gits
The Bread Wonder Trick is useful for releasing new commodities in a large city. However, I didn't know that it works in reverse! Playing the second Early Landing Comparison Game I completed a caravan in the SSC where the wonder was to be built. When I placed the caravan back into the city to "help build the wonder" it blocked my supply commodities.

Is this well know or have I missed something ?

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

SG(2)

Solo will have the definitive response, and a save would be useful. Were there three routes in place?? Were there undelivered commodity vans still "on the road"??

BTW, in the US there is a national brand of bread under the label "Wonder Bread", hence, the Wonder Bread Trick.

Monk

[SCG]

Originally posted by Scouse Gits
The Bread Wonder Trick is useful for releasing new commodities in a large city. However, I didn't know that it works in reverse! Playing the second Early Landing Comparison Game I completed a caravan in the SSC where the wonder was to be built. When I placed the caravan back into the city to "help build the wonder" it blocked my supply commodities.

Is this well know or have I missed something ?
SG(2)

Originally posted by solo
Only three triggers in both games:
.
.
.
3) A caravan delivery to or from the city, or the use of a caravan produced by the city to help make a wonder, acts as an independent trigger, working on any turn to update a city's lists. As with 2.42 cycle turn looks, a "correct" list results. As with MGE multiplayer cycle turn city looks, the use of a caravan will trigger the dye bug in MGE games.

it sounds to me that the city list needed to be updated, and was lacking a trigger, for which the delivery provided. I've noticed that in my own games where other cities still have trade routes to my SSC which i had replaced by deliveries elsewhere, and a trigger reset the list to where the old commodities reappeared, and since there are existing routes in other cities they therefore became blocked.

[solo]

SG(2),

I agree with SCG's reasoning, but would like to see a save if you can provide one.

When supplies are unblocked to begin with, I try not to do anything that might mess things up.

[Elephant]

Solo - did you or Samson do any research into what makes a city's demand not get blocked when demanded commodities delivered? I had a great run with the Mongol city of Karak... in EL#1, it would move its demand around after a delivery but rarely got blocked, sometimes a second delivery unblocked it. Commodities such as Silk, Coal, and Wine kept coming back up again.

[solo]

Elephant,

Commodity demand is blocked when a new trade route is created, or if an existing trade route is replaced. Three established routes with a city (or cities) having high values of base trade in the source city will allow it to deliver commodities to cities with lower base trade without blocking their demands. This is demonstarted in one of my unblocking examples, posted in the EL thread for game #1.

[Scouse Gits]

Originally posted by solo
SG(2),I agree with SCG's reasoning, but would like to see a save if you can provide one.

I will post a save when I finish the game (Early Landing #2)

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

SG(2)

[Elephant]

Originally posted by solo
Elephant,

Commodity demand is blocked when a new trade route is created, or if an existing trade route is replaced. Three established routes with a city (or cities) having high values of base trade in the source city will allow it to deliver commodities to cities with lower base trade without blocking their demands. This is demonstarted in one of my unblocking examples, posted in the EL thread for game #1.

Yes; the focus of my question was on refreshing of the Demanded commodities, not the Supplied.

So if my SSC gets 3 early routes to a city (in EL#1 it was Karakorum), other cities can deliver to Kara without disturbing the primary routes. What I found in EL#1 was that Karas demanded commodities list often refreshed to different, unblocked commodities after each delivery. I'll try to go back through my log and saves and document the changes.

[solo]

Elephant,

Sometimes the new lists are due to an update to lists in which dye or copper are cancelled causing them to be knocked off the demand lists. A following cycle turn in 2.42 re-implements the copper-dye bug in AI cities. This bug is the underlying cause for many wholesale list changes during a game.

[solo]

I have bumped this since the link was not working.

[hardjoy]

Impressive stuff... always wondered how this worked -its been very helpful. I am in the process of polishing up a historical scenario and I wanted the trade goods somewhat reasonable for the period. Your guide gave me a couple of hints about which ressources to rename for effect.

Still I wonder how some trade goods can be in so extremely high demand, yet just a few cities or even none supply them. In scenarios this system sometimes lead to extremely absurd trade situations, but now at least I understand the beauty of it