How is a starting spot determined?

A few weeks ago I posted this thread over on Reddit asking why I didn't spawn where Krakow is and was told that the start was literally too good and that capitals don't spawn within working distance of natural wonders.

The other day I found this thread showing a starting location with Old Faithful in working distance. So what exactly determines a starting location? The obvious reason why the Krakow location wasn't chosen was from the lack of a second luxury resource but you can argue that the locations' overall brilliance makes up for it. So if spawning next to a natural wonder isn't a criteria for start location what else is involved?

Link to the two starts in question if anyone can't use Reddit.

each Civ has their own start bias (eg: Venice will always spawn on the coast, Arabia will always spawn in the desert, etc -- see http://civilization.wikia.com/wiki/Starting_bias_(Civ5) for the full list)

I believe that there's logic within the start bias that no Civ will have their first settler spawn within 4 tiles of a natural wonder. but it looks like Poland discovered Lake Victoria and promptly plopped their second settler next to it.

Starting bias, which every civ has, is how starting positions are determined. Beginning next to a natural wonder or two is simply luck of the draw, since they are assuredly randomly generated along with the rest of the map if it's on a script. Most starting positions also seem to have anywhere from 2-3 luxuries and a bonus resource or two to start them out from most games I've played. I am not sure whether this is intentional or not although I would not be surprised if it was.

The map with Brazil looks like the player has added more civs and cs than the map can handle and has given them that space because the other start locations are taken.

Desert
Arabia
Morocco

Coast

Byzantine
Venice
Portugal
Spain
Denmark
England
Indonesia
Carthage
Korea
Polynesia
Ottoman

Forest

Iroquois
Celts

Grassland

Dutch
India

Hills

Austria
Inca

Jungle

Brazil
Aztec

Plains

Mongols
Poland

Tundra

Sweden
Russia

Avoid Forest/Jungle

Huns
Egypt
Siam
Zulu

Avoid Tundra

Songhai
Assyria
Babylon

For example, if Swedens bias was tundra, it could be tundra with forest, hill, and other natural occurences

Civs without start bias can start anywhere on land. (America, Persia etc)