Implications of and comments on, trade code distribution

[captainjack23]

I'll kick this off by posting my crunch of the distribution of the trades codes.

Ag	12
AS	3
Ba	3
De	8
Fl	9
Ga	17
Hi	8
Ic	14
In	4
Lo	17
Na	5
Ni	58
Po	13
Ri	4
Va	13
Wa	10

Notes: computed with the Mong Trav values.
more notes and previous calculations in the Stat thread.

EDIT: To clarify, these use the trade code criteria in MGT as printed, unmodified by anyone (myself included).

 

[captainjack23]

And now, my first notes on changing the values:
(from the stats thread)

A quick example of the changes a simple +1 can make:

In w/. pop 9+ = 3.6% (MongTrav)
Pop 8+ = 7.3 %
Pop 7+= 12.3 %

Now, assuming a subsector of 40 planets, the chance of NOT getting an In planet is 23% based on the Mon/CT values.

for Pop 8 it is 4.8 %
for Pop 7 it is .5%

Which is to say, there should be a minimum of 3 In worlds per 4 Subsectors
or 40*3.6 = an average of 1.44 in a given subsector - with a variance close to .5. So, usually one, sometimes two.

Now, for pop 8+ we get:
pretty much one or more In worlds per subsector , with an average of 2.92, with the same variance - so VERY likely two /Subsector, with three being not unlikely.


Practically, going from sometimes 1 In world per subsector to very likely 2 to 3 is a BIG change in terms of trade.

 

[EDG]

Hm. Here's a comparison between your first table and the actual results I got from the MGT run:

     CJ     EDG
Ag   12    13.5
AS   3      2.7
Ba   3      2.8
De   8      5.0
Fl   9      9.0
Ga   17    25.4
Hi   8      8.2
Ic   14     6.6
In   4      4.2
Lo   17    25.8
Na   5      9.1
Ni   58    70.8
Po   13    14.3
Ri   4      4.8
Va   13     8.4
Wa   10     9.7

Some of them are close, but there's a bit of a huge difference between our Ic, Ga, Lo, Na, Ni and Va results.

That means either you're calculating something incorrectly, or there's more bugs in my code, or (most likely) you're not doing exactly what I was doing to generate my results (check the changes/clarifications block at the top of the MGT UWP thread).

For Ic are you remembering to do the -4 DM for atm 0 (and it applies to nothing else in the MGT rules)?

 

[captainjack23]

For Ic are you remembering to do the -4 DM for atm 0 (and it applies to nothing else in the MGT rules)?

Not if it wasn't listed in the table at the top of the thread, so that would explain that one.

Really, what I did was this:

1. Calculated all combinations possible for the first roll (SZ or Pop) followed by a secondary roll (ATM,HYD and GT), (2d6x2d6=36^2 combinations.
2. Assigned each of the traveller codes 0-C (or A if capped at A) an outcome frequency
3. and then used those frequencies to compute the probability of any one trade code.


The frequency table is the first post in the stats thread.

I used the list posted by Grufty to assemble the trade code probs.

Most of the small differences are likely due to the fact that you're estimating, and I'm using exact counts....given the numbers of runs, your runs probably fall within a reasonable error around the exact count.



Not sure about the bigger ones. You're right about why. Your code, my process, who knows ? I'll check what I used for conditional odds in the basic permutations to code value part - thats where it'll show up.
I'm pretty sure about the permutations table-those is straightforward products.


edit: Also, Looking at the differences in our lists, even some of the larger discrepencies seem to be within margin for observed error - if you don't know the variance of a sample distribution (and we don't) , the best rule of thumb is to use the observed average +- about half.
so, a result of 18 has an error band including values from 9 to 27. Some of the more discrepant of your results do include the exact count value in such an error band, so your differences are likely it due simply to random variance.

Its not a great rule of thumb, but it works surprisingly well for % estimations.

 

[captainjack23]

6) In code is the same as CT (not atm 2-4,7-9 and pop 9+ as stated in MGT 3.2).
7) Lo and Ni are minimum pop 1.

9) Lt code applies only if pop 1+.

I think these are the main differences. In your stats you used your criteria, I used the ones in MGT as is. I was hoping to get the baseline for unmodified MGT, with no editorial input (from me or anyone).

Part of it is due to you dropping the 0 values in several of the codes, I suspect. If you'll look at the chart, the secondary frequency of 0 (for ATM, HYD and GVT) are much higher, as all lower results are defaulted to 0. Its more severe even than at the capping effect at the C end.

A result of C has 35 possible ways to be made, whereas you have 126 for a result of 0. And 126 is about 10% (9.7%, IIRC)of any of the secondary distributions. That'll skew our results in different directions.

Since we had different goals, and used different definitions, our results are only semi-comparable as a result.

There may be more differences, I'll look some more.

 

[EDG]

I think these are the main differences. In your stats you used your criteria, I used the ones in MGT as is. I was hoping to get the baseline for unmodified MGT, with no editorial input (from me or anyone).

I did want to do that, but it was clear that some things just wouldn't work and would give daft results if I did. The In code is obviously wrong - atm 3 and 8 have never been part of the In code in Traveller before and he missed out atms 0 and 1 too - so that had to get replaced by the CT version.

And the min population of 1 has to apply because it makes no sense to call a zero population world a low pop world or to give it a trade code if there's nobody to trade with.

Most of the small differences are likely due to the fact that you're estimating, and I'm using exact counts....given the numbers of runs, your runs probably fall within a reasonable error around the exact count.

Aren't you the one that's estimating? . After all, I'm using the actual numbers generated to calculate the statistics, whereas you're telling me what the theory predicts? Assuming my code is correct (and it looks like it is now, fingers crossed), and assuming you're doing exactly what I'm doing, your numbers should come out roughly the same as mine.

That said, to get a more accurate measurement here I really should do three runs (at least) and take the average again, but I won't have the time to do that til Thursday night

 

[AKAramis]

Statistics 101: doing the math of a known probability is more accurate to the probability than any sample of the applied probability.

 

[Settembrini]

@EDG: You made me register at this site.

First of all, let me thank you for your efforts! They are greatly needed and appreciated!

BUT: You have repeatedly stated stuff axiomatically that´s just NOT TRUE!

You are making implicit or explicit assumptions.

For example, a Pop Zero World has a population of 0-9! Don´t forget that

POP = n*10^k

where n is the Pop multiplier from the expanded UWP (not in MGT as far as I know, so it defaults to 1)
and k is the UWP Pop digit.

10^0 = 1

 

[atpollard]

For example, a Pop Zero World has a population of 0-9!

While technically true, there is a valid point to be raised about the basic logic that a world with 9 people wants to purchase 8 ATVs, 6 dTons (84 cu.m./2856 cu.ft.) of pharmaceuticals, and 100 dTons (1400 cu.m./47,600 cu.ft.) of iron ore because some random 'sale' table says so.

 

[anselyn]

For example, a Pop Zero World has a population of 0-9! Don´t forget that
POP = n*10^k
where n is the Pop multiplier from the expanded UWP (not in MGT as far as I know, so it defaults to 1)
and k is the UWP Pop digit.

10^0 = 1

On population, do we really think that population C is viable on any world? A quick calculation suggest to me that's the same order of magnitude as having the population density of Hong Kong or Singapore over every square kilometer of the Earth.

How do understand that for, say, a size 5 world that 50% water covered (or alternatively a desert) and TL 6 - or at that point are we happy to invent the rationale?

Alternative, cap population at B?

 

[atpollard]

On population, do we really think that population C is viable on any world? A quick calculation suggest to me that's the same order of magnitude as having the population density of Hong Kong or Singapore over every square kilometer of the Earth.

How do understand that for, say, a size 5 world that 50% water covered (or alternatively a desert) and TL 6 - or at that point are we happy to invent the rationale?

Alternative, cap population at B?

The chance is so remote that I would prefer to keep the world.

For what it might be worth, Hong Kong has an Urban Density of 29,400 people per sq.km., so covering the 148.9 million sq. km. of earth's land with 'Hong Kong' would support roughly 4 x 10^12 people - Pop C will just fit.

On the other hand, even in Hong Kong, few buildings exceed about 40 to 60 stories. By building structures that are 400 to 600 stories (a 2 km high city) that same population could fit on 10% of the earth's land Area (cover all the deserts with city).

Large Orbital cities to support a huge space infrastructure are another alternative. Consider, for example, that a flat plate at geostationary orbit that was 562 km wide would have a surface area roughly equal to the land area of the Earth. Plenty of surface area to build a city on.

 

[EDG]

You are making implicit or explicit assumptions.

I know I am. I've been pretty explicit about it.

For example, a Pop Zero World has a population of 0-9!

Not in MGT it doesn't. MGT doesn't have a pop multiplier.

Though I guess I could actually put something in the other code that says that if the pop roll is exactly 0 then the pop is 1-9 people, but if it's less than 0 then it's no people at all.

But yes, I am aware of all this, and I think so far that I have made it pretty explicit that I've been assuming that pop 0 really does mean "no people"

 

[EDG]

The chance is so remote that I would prefer to keep the world.

Funnily enough though - with my EDG modifications, you can get pop C worlds with 5/6/8 atmospheres since I have a DM+2 for the pop roll for those atmospheres.

Large Orbital cities to support a huge space infrastructure are another alternative. Consider, for example, that a flat plate at geostationary orbit that was 562 km wide would have a surface area roughly equal to the land area of the Earth. Plenty of surface area to build a city on.

I think that's exactly how those worlds become viable. Either they're all crammed onto the surface or they're in stations and orbital cities around the planet (or even on the rest of the planets in the system if you really want to stretch the pop definition).

 

[SableWyvern]

I think that's exactly how those worlds become viable. Either they're all crammed onto the surface or they're in stations and orbital cities around the planet (or even on the rest of the planets in the system if you really want to stretch the pop definition).

Also: skyscrapers/arcologies stretching up into vacuum, anti-grav cities floating amonst the clouds or on the oceans, submarine and sub-surface cities. I really like the idea of skyscrapers complete with their own private highports at the top - essentially space elevators, I suppose.

In any case, at higher tech levels, there are plenty of ways to deal with high populations.

 

[anselyn]

I think that's exactly how those worlds become viable. Either they're all crammed onto the surface or they're in stations and orbital cities around the planet (or even on the rest of the planets in the system if you really want to stretch the pop definition).

Also: skyscrapers/arcologies stretching up into vacuum, anti-grav cities floating amonst the clouds or on the oceans, submarine and sub-surface cities. I really like the idea of skyscrapers complete with their own private highports at the top - essentially space elevators, I suppose.

In any case, at higher tech levels, there are plenty of ways to deal with high populations.

But not at low ...

 

[EDG]

In any case, at higher tech levels, there are plenty of ways to deal with high populations.

But not at low ...

Maybe we need more pop DMs (+6 at pop B, +8 at pop C?) to push those worlds away from the low TLs?

 

[captainjack23]

Statistics 101: doing the math of a known probability is more accurate to the probability than any sample of the applied probability.

EDG, Aramis, is, I fear, correct. Your approach estimates initial probabilities and distributions from a sample . Unless you generate every possible combination of every result, and count them all, you are sampling.

Conclusions from samples are always a bet, very often a informed one, even a very likely one, but still a guess. It's especially the case if you don't know what he liklihood is of your samples differing from the real values.

That said, introducing your versions of tradecodes into the baseline, not only makes your values non-compatable with mine, it also makes the comparison of your explicit changes moot...they are really just a comparison of two versions of your own data.

We are here to playtest MGT, so I felt we needed to get an idea of what they looked like, before we considered changing them..daft or not.
Daft is in the eye of the beholder, anyway, even when we agree, that just means there are two beholders, not a fact, and two beholders have to have a terrifit chalenge level (despitemassive XP value) and who wants that ? That stupid joke was a reward for anyone reading all the way through.

 

[captainjack23]

You are making implicit or explicit assumptions.

I know I am. I've been pretty explicit about it.

For example, a Pop Zero World has a population of 0-9!

Not in MGT it doesn't. MGT doesn't have a pop multiplier.

Though I guess I could actually put something in the other code that says that if the pop roll is exactly 0 then the pop is 1-9 people, but if it's less than 0 then it's no people at all.

But yes, I am aware of all this, and I think so far that I have made it pretty explicit that I've been assuming that pop 0 really does mean "no people"

which isn't actually what the MGT rules say.

 

[EDG]

We are here to playtest MGT, so I felt we needed to get an idea of what they looked like, before we considered changing them..daft or not.

OK... I don't need statistics to tell me that the MGT definitions are wrong. A world cannot be "Lo" with no people on it. It can't be "Ni" with no people on it. It can't be "Lt" with no people to have any technology. It can't be "In" with atm 8. So I corrected those.

It doesn't invalidate anything to change that, and it means I don't waste time testing a system that has broken codes and that produces obviously nonsensical results. And until and unless Gar comes on here and says "EDG's implementations are incorrect, they're actually supposed to be like X" then I'll continue to test using my corrected MGT codes. And if he does do that then I'll change the code to whatever he says to change it to.

But I have PM'd Gar to get clarification on that to remove this issue. I will implement what he says for MGT. I'm pretty sure he'll agree with me about the Lo, Ni, and Lt worlds. He may have intended something else for "In" perhaps, but we'll see.

 

[EDG]

But yes, I am aware of all this, and I think so far that I have made it pretty explicit that I've been assuming that pop 0 really does mean "no people"

which isn't actually what the MGT rules say.

Where does it say otherwise?

A pop code of 0 has to mean no people if MGT has no way to determine pop multipliers built into it. Otherwise every single world has at least one person on it, which is silly.