ThinkTank
RL Addict
This thread continues a discussion that was started in the thread Favourite wonder in posts 43, 45, 46 and 47.
The issue, at least to me, is to understand the role of granaries in efficient REX. In REX you want as many cities as possible as soon as possible. Do you need granaries for that? And if the answers is "it depends", what does it depend on?
Now here is an answer to that question:
I disagree with these criteria.
In order to give an exampe of what I mean, consider a map that only has 2spft city locations, we are at turn 0 of the game, so at the start of REX, so we only have the capitol. Should we build a granary first, or start building settlers right away? According to the criteria described by MAS, you should not build a granary.
According to me, it depends on the number of cities you will be able to grab in REX. The reason I think this is the case in general is as follows.
Mechanism 1: building a settler first has the advantage that you get your second city sooner, as well as everything that is produced by the second city. This city can also build setllers, making you grow faster. This mechanism reinforces itself for what is produced by any city founded by a settler produced by the second city, since these are also sooner, and so on.
Mechanism 2: building a granary shortens the production time for settlers.
I think that mechanism 1 gives you a better initial growth, but that mechanism 2 compensates for not having mechanism 1 in the long run. By which I mean that there is a break even number x such that if the number of settlers you need becomes larger than x, mechanism 2 will get you the settlers faster.
I will illustrate this in the scenario sketched. I am assuming a map with only BGs. Only 2sfpt cities ever. This means we can do 2 growth in 20 without a granary, 2 growth in 10 with a granary. I also assume that we can improve tiles fast enough that we can do 3s(shields) at size 1, 5s at size 2, 7s at size 3, and so on. I will compare two strategies that only differ in the first city building a granary or not. All subsequent cities founded will be building settlers (without a granary). I will assume that a settler takes 5 turns before it founds a city.
Strategy 1: no granary ever. The earliest settler that can be produced is at turn 20 (growth to three). After that, a settler every 20 turns. All cities founded later follow this strategy.
Strategy 2: granary first in first city. All later cities follow strategy 1.
Since we cannot produce 90 shields in the first 20 turns I assume that in the first city we produce the first settler at turn 30 (growth to 4), then a settler every 10 turns.
In the attached Excel sheets I have calculated all settlers produced and towns founded and settlers produced by towns founded and so on for the first 100 tuns or so:
After 105 turns we have 17 cities with 3 settlers on the move in the no granary strategy; 23 cities and 4 settlers on the move in the granary strategy. The break even point appears to be at 7-8 cities.
You can find the complete Excel sheet here:
The issue, at least to me, is to understand the role of granaries in efficient REX. In REX you want as many cities as possible as soon as possible. Do you need granaries for that? And if the answers is "it depends", what does it depend on?
Now here is an answer to that question:
To decide if a granary is useful, determine what increases growth (measured in surplus food per turn, or sfpt) the most: a granary, or a settler?
A settler increases growth by the amount of surplus food the next city-site can grant.
The granary doubles growth of the city you are building it.
If the current city produces 5 sfpt, a granary is worth 5 sfpt! And since it costs 60 shields, that is 12 shields per sfpt.
If the current city produces 4 sfpt, a granary is worth 15 shields per sfpt.
If the current city produces 3 sfpt, a granary is worth 20 shields per sfpt.
If the current city produces 2 sfpt, a granary is worth 30 shields per sfpt.
If the future city-site grants 2 sfpt, a settler is worth 15 shields per sfpt.
If the future city-site grants 3 sfpt, a settler is worth 10 shields per sfpt.
If the future city-site grants 4 sfpt, a settler is worth 7.5 shields per sfpt.
If the future city-site grants 5 sfpt, a settler is worth 6 shields per sfpt.
So as you can see if the future city can output 2 sfpt, a granary in the current city is only worth it if the current city already has 5 sfpt, and is almost equal if its has 4 sfpt. (the granary will also cost maintenance, and the city will also add shield and commerce output, in addition to unit support, with 4 sfpt a settler is still a better choice.)
If future city sites have more than 2 sfpt, even a 5 sfpt doesn't justify a granary, and a settler should be build instead, until all hight food sites are settled.
I disagree with these criteria.
I have to disagree. The problem with this argument is that it considers the choice between a settler and a granary as a one-off decision.
It depends on the circumstances if that is right.
At the start of REX, in a food poor starting location (only 2 sfpt locations),
but with a lot of room to expand to (say large or huge map), a granary first will shorten the production cycle of many settlers to come,
even if it will delay the production of the first or first few settlers. So the real value of the granary (at least for REX) must depend on the number of settlers that will be built in the city.
At the end of REX, in a city that will maybe only build 1 settler before expansion is over, the considerations by MAS are valid.
In general I think the right perspective is something like the following. A granary first will always pay of in the long run. It must be able to calculate how long that run is, that is, how many settlers that is; the answer will likely vary with shields and food production. Suppose that n settlers is the turning point. Then if you think REX is going to last longer than n settlers build a granary first, otherwise don't build one.
In order to give an exampe of what I mean, consider a map that only has 2spft city locations, we are at turn 0 of the game, so at the start of REX, so we only have the capitol. Should we build a granary first, or start building settlers right away? According to the criteria described by MAS, you should not build a granary.
According to me, it depends on the number of cities you will be able to grab in REX. The reason I think this is the case in general is as follows.
Mechanism 1: building a settler first has the advantage that you get your second city sooner, as well as everything that is produced by the second city. This city can also build setllers, making you grow faster. This mechanism reinforces itself for what is produced by any city founded by a settler produced by the second city, since these are also sooner, and so on.
Mechanism 2: building a granary shortens the production time for settlers.
I think that mechanism 1 gives you a better initial growth, but that mechanism 2 compensates for not having mechanism 1 in the long run. By which I mean that there is a break even number x such that if the number of settlers you need becomes larger than x, mechanism 2 will get you the settlers faster.
I will illustrate this in the scenario sketched. I am assuming a map with only BGs. Only 2sfpt cities ever. This means we can do 2 growth in 20 without a granary, 2 growth in 10 with a granary. I also assume that we can improve tiles fast enough that we can do 3s(shields) at size 1, 5s at size 2, 7s at size 3, and so on. I will compare two strategies that only differ in the first city building a granary or not. All subsequent cities founded will be building settlers (without a granary). I will assume that a settler takes 5 turns before it founds a city.
Strategy 1: no granary ever. The earliest settler that can be produced is at turn 20 (growth to three). After that, a settler every 20 turns. All cities founded later follow this strategy.
Strategy 2: granary first in first city. All later cities follow strategy 1.
Since we cannot produce 90 shields in the first 20 turns I assume that in the first city we produce the first settler at turn 30 (growth to 4), then a settler every 10 turns.
In the attached Excel sheets I have calculated all settlers produced and towns founded and settlers produced by towns founded and so on for the first 100 tuns or so:
After 105 turns we have 17 cities with 3 settlers on the move in the no granary strategy; 23 cities and 4 settlers on the move in the granary strategy. The break even point appears to be at 7-8 cities.
You can find the complete Excel sheet here: