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The problem with Sail to Europe tile distance
I noticed when starting new games a couple of times that I would sometimes be placed far from land. Also the very eastern and western edges of the map seemed to be the only viable sailing points.
So I did a little looking into this. The way maps are generated, the four (4) eastern most tiles of ocean are Sail to Europe tiles, and the five (5) western most tiles of ocean are Sail to Europe tiles. Land can never be closer than 3 tiles, otherwise the sailing tiles shrink to adjust.
This causes some pretty glaring problems. First, sailing distance to Europe should be a primary concern of your first colony. The longer it takes you to get goods to and from Europe, the further behind you get. Second, depending on the distance to land, you can spend many of your crucial first turns looking for land that just isn't there. Finally, it really limits the starting location options for the generator--European nations will typically spawn one on top of the other on bad map gens.
The problem is particularly more prevalent the larger the map gets. I shall illustrate.
Example A: Here is a particularly long run.
This example is from the scenario map Western Hemisphere. But it shows how large landmasses can be so far away from Europe as to make settling them pointless. Also note how the English player is totally screwed. I shall refer to these situations lovingly--borrowing a term from Age of Empires--as "Map Screws."
Example B: A pretty hefty map screw.
The game will try to place you within 4-5 tiles of terrain from Europe. However, sometimes it can't find anything suitable and you get a situation like the above. The actual sailing distance to anything useful is 12 tiles. That more than triples my sailing time to Europe for all my vessels.
Example C: Here is a generated terrain with excessively long travel times to the innards.
Here's another example. Now the game does start the player within five tiles of land. That's one of three directions the player could assume to sail (there's no hint on which way is correct). So the player could potentially spend 3-5 turns just sailing aimlessly. Founding starter colonies on those internal peninsulas is just suicide.
Rather than prattle on endlessly, I did a small sum of data collection on Standard and Huge maps:
Standard
- Player - Starting distance (Parenthesis accounts for map screw) for game N
- ME - 5 - 4 - 4 - 4 - 4 - 4
- CPU1 - 5 - 4 - 5 - 4 - 4 - 4
- CPU2 - 5 - 6 - 4(8) - 4 - 5
Player Map Screw % - 16% of games 'screwed'
Huge
- ME - 4 - 5 - 4(12) - 4(7) - 4
- CPU1 - 6 - 5 - 4 - 5 - 6 - 4(6)
- CPU2 - 5 - 5 - 4 - 5 - 4 - 4(11)
- CPU3 - 8 - 4 - 6 - 5 - 5 - 8
Player Map Screw % - 50% of games 'screwed'
So in the cases where I get screwed, it's pretty easy to restart. However, the AI has to suffer the consequences and have some particularly hobbled starts. I suspect the problem is magnified in MP as nobody will want a poor start like that.
And then?
So there's the problem of the map screw, which is magnified (and perhaps caused) by the distance to Europe. Guessing from my starts above, the desired distance to Europe is 4-5 squares. This distance makes it highly desirable to upgrade to a Merchantman as soon as possible, so I'll consider it somewhat sacred.
One solution is to draw the Sail to Europe closer to land. The original Colonization did a pretty good job of this, and it made maps with large gulfs possible to still colonize the interior. See the America map from that game as an example.
How would this work in Civ4:Col? Filling in from the edges, stop drawing tiles at a distance that's five (5) water tiles from a shore. The distance drawn without making diagonal traversals. This number could be tweaked, of course.
Example D: Here's an actual map with mountains to represent the new concept.
In this example, a player who normally has to travel 8 tiles to Europe would then only have to travel five or six. In the case of large gulfs that would normally be inaccessible to Europe, the fill would bring the Europe travel time right to their shores, allowing colonization possibilities. And also allowing for a much large variation in starting locations.
Will it eliminate map screws? Not unless it's paired with something to check the size of the nearest land mass. Rejecting landmasses under 5 tiles in size is probably an adequate start.
However it will help to reduce the incidence of them, and reduce the fallout from having to look for something further in on the map. From my examples, in example B, the player could make it to the second island further in, but still have reasonable sailing time to Europe. In that case, they'd only be out the time required to find the second island, rather than the sailing time AND the Europe-colonial sailing time for all the following trips.
So I did a little looking into this. The way maps are generated, the four (4) eastern most tiles of ocean are Sail to Europe tiles, and the five (5) western most tiles of ocean are Sail to Europe tiles. Land can never be closer than 3 tiles, otherwise the sailing tiles shrink to adjust.
This causes some pretty glaring problems. First, sailing distance to Europe should be a primary concern of your first colony. The longer it takes you to get goods to and from Europe, the further behind you get. Second, depending on the distance to land, you can spend many of your crucial first turns looking for land that just isn't there. Finally, it really limits the starting location options for the generator--European nations will typically spawn one on top of the other on bad map gens.
The problem is particularly more prevalent the larger the map gets. I shall illustrate.
Example A: Here is a particularly long run.
This example is from the scenario map Western Hemisphere. But it shows how large landmasses can be so far away from Europe as to make settling them pointless. Also note how the English player is totally screwed. I shall refer to these situations lovingly--borrowing a term from Age of Empires--as "Map Screws."
Example B: A pretty hefty map screw.
The game will try to place you within 4-5 tiles of terrain from Europe. However, sometimes it can't find anything suitable and you get a situation like the above. The actual sailing distance to anything useful is 12 tiles. That more than triples my sailing time to Europe for all my vessels.
Example C: Here is a generated terrain with excessively long travel times to the innards.
Here's another example. Now the game does start the player within five tiles of land. That's one of three directions the player could assume to sail (there's no hint on which way is correct). So the player could potentially spend 3-5 turns just sailing aimlessly. Founding starter colonies on those internal peninsulas is just suicide.
Rather than prattle on endlessly, I did a small sum of data collection on Standard and Huge maps:
Standard
- Player - Starting distance (Parenthesis accounts for map screw) for game N
- ME - 5 - 4 - 4 - 4 - 4 - 4
- CPU1 - 5 - 4 - 5 - 4 - 4 - 4
- CPU2 - 5 - 6 - 4(8) - 4 - 5
Player Map Screw % - 16% of games 'screwed'
Huge
- ME - 4 - 5 - 4(12) - 4(7) - 4
- CPU1 - 6 - 5 - 4 - 5 - 6 - 4(6)
- CPU2 - 5 - 5 - 4 - 5 - 4 - 4(11)
- CPU3 - 8 - 4 - 6 - 5 - 5 - 8
Player Map Screw % - 50% of games 'screwed'
So in the cases where I get screwed, it's pretty easy to restart. However, the AI has to suffer the consequences and have some particularly hobbled starts. I suspect the problem is magnified in MP as nobody will want a poor start like that.
And then?
So there's the problem of the map screw, which is magnified (and perhaps caused) by the distance to Europe. Guessing from my starts above, the desired distance to Europe is 4-5 squares. This distance makes it highly desirable to upgrade to a Merchantman as soon as possible, so I'll consider it somewhat sacred.
One solution is to draw the Sail to Europe closer to land. The original Colonization did a pretty good job of this, and it made maps with large gulfs possible to still colonize the interior. See the America map from that game as an example.
How would this work in Civ4:Col? Filling in from the edges, stop drawing tiles at a distance that's five (5) water tiles from a shore. The distance drawn without making diagonal traversals. This number could be tweaked, of course.
Example D: Here's an actual map with mountains to represent the new concept.
In this example, a player who normally has to travel 8 tiles to Europe would then only have to travel five or six. In the case of large gulfs that would normally be inaccessible to Europe, the fill would bring the Europe travel time right to their shores, allowing colonization possibilities. And also allowing for a much large variation in starting locations.
Will it eliminate map screws? Not unless it's paired with something to check the size of the nearest land mass. Rejecting landmasses under 5 tiles in size is probably an adequate start.
However it will help to reduce the incidence of them, and reduce the fallout from having to look for something further in on the map. From my examples, in example B, the player could make it to the second island further in, but still have reasonable sailing time to Europe. In that case, they'd only be out the time required to find the second island, rather than the sailing time AND the Europe-colonial sailing time for all the following trips.
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