by: Leonard

In article <336F37D0.449@earthlink.net>,

aabraham@earthlink.net wrote:

> What is it about CA that makes them so good at getting resources?

> I've heard all these ???k by 2450 strings with CA, but no explination of

> why CA works so well.

Because of the free terraforming.

Recall that there are just two possible sources of resources: pop, and factories. And it takes pop to run factories. So, in fact the main limit to resource growth is pop growth. Everything else is secondary to that.

Now consider the limits to pop growth. There are three: the pop growth percentage (obvious), available space, and the habitibility percentages. Any race can boost the first just by paying in the wizard, and most do, since it is cheap. The second and third are related. A wide hab gets you both more planets and better average hab per planet. But cost of wide hab is strongly correlated with the pop growth rate. Play with the wizard for a bit; this should be obvious.

What this means is: most races can either have high growth, or high hab, but not both. So, a 19% growth race will buy as wide hab as possible, but it will still end up something like 15 clicks in from either endpoint on all three variables. And this, in turn, means that the starting habitability is not great: the average hab on *one* dimension is just 35%; in all, you should expect something in the ballpark of 34% planets habitable at all, with an average of 50% hab each.

[Side note: I am assuming that habitat ranges compose linearly, that is, if you have 50% on each one, they each add 50%/3 to the total and you get (of course) 50% out. But this is NOT how it actually works; the problem is, I don't know how it works. I have seen double-immune races have habs in the 50s; go figure. My suspicion is that the actual hab percentage formula is worse than linear. Thus CAs will be even stronger than I calculate.]

Anyway, once you get to 25% maxpop on the homeworld, you should expect *much* worse pop growth; 34% of planets habitable is not going to be a problem early (there should be plenty of greens), but the 50% hab is a problem. This means only 9.5% pop growth. 9.5% over 50 years gives a multiplier of 93.4. Not enough.

Terraforming has a very strong effect on habitability. Consider the same race as before, but assume 5% terraforming on all variables. This gives average hab on one dimension of 45%, about 1 in 2 habitable. And the average hab% for the greens jumps to 56%, on average. This may not seem like much, but look at the effect over 50 years: a 10.64% rate compounds the initial amount 156.9 times. I.e., more than 50% more than without terraforming. Better.

Of course, there is a downside here: you have to pay for all that expensive terraforming with the planet itself, which is small, and thus poor. It needs to grow to get rich, but it cannot grow much because of low habitat -- a catch-22 situation. Unless you are CA. Then the terraforming is both free and instantaneous. And THAT is a big part of why CAs currently rule.

Just to complete the analysis, let's look at all the cases reasonably achievable in 50 years:

Y-G% = percentage of planets yellow or green

AvG% = average maximum hab percentage for greens

CG50y = compounded growth for 50y at the AvG% and 19%.

Amount Y-G% AvG% CG50y

0% 34% 50% 93.4

3% 44% 54% 131.5

5% 51% 56% 156.9

7% 59% 58% 191.6

10% 73% 61% 242.9

11% 78% 62% 261.0

15% 100% 65% 337.8

(Actually, TT+20 can be done too, at least in test games.)

One other thing to note about CAs: that extra 1% shift every ten years adds up. You can see, above, the effect of moving all three variables from 10 to 11%; fairly dramatic for such a small shift. Throwing on this extra terraforming over time makes the CA great in the long run, as well as the short. Very powerful.

If I were named Jeff, I would reimpose a cost for CAs to terraform (if bought on planets). I believe it used to be 50% as much as normal races (i.e. 50 or 35 points). CAs would still have the cheap terraforming from their orbital adjusters, so this should not affect them much in the long term or even the midterm, but it would cut down quite a bit the current CA ability as best hypergrowth race. Also, I would remove the auto-unterraforming when a CA leaves a planet.

-Leonard

leonard@alw.nih.gov