We all know that under the default 2:1 city state ratio & spies on that Diplomatic victory always takes fewer turns under almost all circumstances than either science or cultural so I won't go into that.
Neither will I go into comparing them with domination victory turn times.
It's also clear that Brazil can always get a faster victory going cultural than science. (Largely GA driven after they get their base tourism high enough but their UI also helps with this once Hotels are reached)
But in the other direction, Babylon is designed to get the fastest Science Victory possible, but with more science actually helping all victory conditions, it's not always the case that science will be faster than cultural. Korea also has a big science bonus, but with it also giving science bonus from the guild specialists they may actually lean towards the cultural side.
It turns out that when playing a generic civ (one without any cultural or tourism bonuses) that the standard cultural victory is largely theming great works + tourism driven.
So first, what generates more guild specialists:
1. Garden (requires fresh water unless playing Indonesia)
2. Coffee House (requires you to be playing Austria)
3. Aesthetics opener
4. National Epic
5. Leaning Tower (also provides free great person)
6. Arts Funding (normally popular with the AIs if proposed early, the faster the better so you do want to meet the world.)
Stacking all those faster spawn rates is so important, that if you don't have a fresh water start then unless playing Indonesia or Austria that science victory is likely to be faster. (This situation would also slow down a science victory, but not by as much)
Leaning Tower is normally hand built, and because there are only 2 world wonders + 1 national wonder providing Writing theming bonuses to 3 world wonders +1 national wonder + standard buildings providing Art theming bonuses, using it for the Globe is actually the best option.
The number of turns you save from Leaning Tower + Globe is massive. If you don't have anything to make it up, then if you miss this it's going to result in science victory being faster.
(For a similar reason, if you are on a low enough difficulty level to complete Great Library, it will actually shave more turns off a cultural victory than a science one. [It would also be weird if you got beat out to Leaning Tower after successfully building the Great Library])
So in fact, that is the best guideline, if on turn 0 you are on fresh water and see your capital producing a lot of hammers by Printing Press from say lots of fresh water hills and mining luxaries, then it's looking really good for a cultural victory.
If instead you see yourself with massive flood plains start with some luxury type that provides gold instead of hammers and most of the desert is flat then science victory is a better option.
On the margin, pantheons providing culture will help a cultural victory after Hotels as would Japan's fishing boats. (Same applies to Monasteries with Wine or Incense)
For science victory, early on the AIs generally hate the idea of Science Funding, so its not as important to have the world congress early. However, after mid game the AIs often start preferring science funding which is when this can be safely proposed to squeeze one more Great Scientist out.
Civs with Hills bias: This tends towards a high hammer start which leads to cultural victory.
Iroquois (who leaves the forest intact) : Their normal problem prior to the introduction of cargo ships and caravans to getting their capital big enough to work all the hammers has been food driven. If this is a coastal start, the food cargo ships will help it grow fast enough to easily hand build Leaning Tower for the twofer. If inland (and limited to caravans), I don't know if that is the case or not.
The other start biases are much more mixed. (Hills vs Flat), and in case of the Celts, what's underneath the forest?
Neither will I go into comparing them with domination victory turn times.
It's also clear that Brazil can always get a faster victory going cultural than science. (Largely GA driven after they get their base tourism high enough but their UI also helps with this once Hotels are reached)
But in the other direction, Babylon is designed to get the fastest Science Victory possible, but with more science actually helping all victory conditions, it's not always the case that science will be faster than cultural. Korea also has a big science bonus, but with it also giving science bonus from the guild specialists they may actually lean towards the cultural side.
It turns out that when playing a generic civ (one without any cultural or tourism bonuses) that the standard cultural victory is largely theming great works + tourism driven.
So first, what generates more guild specialists:
1. Garden (requires fresh water unless playing Indonesia)
2. Coffee House (requires you to be playing Austria)
3. Aesthetics opener
4. National Epic
5. Leaning Tower (also provides free great person)
6. Arts Funding (normally popular with the AIs if proposed early, the faster the better so you do want to meet the world.)
Stacking all those faster spawn rates is so important, that if you don't have a fresh water start then unless playing Indonesia or Austria that science victory is likely to be faster. (This situation would also slow down a science victory, but not by as much)
Leaning Tower is normally hand built, and because there are only 2 world wonders + 1 national wonder providing Writing theming bonuses to 3 world wonders +1 national wonder + standard buildings providing Art theming bonuses, using it for the Globe is actually the best option.
The number of turns you save from Leaning Tower + Globe is massive. If you don't have anything to make it up, then if you miss this it's going to result in science victory being faster.
(For a similar reason, if you are on a low enough difficulty level to complete Great Library, it will actually shave more turns off a cultural victory than a science one. [It would also be weird if you got beat out to Leaning Tower after successfully building the Great Library])
So in fact, that is the best guideline, if on turn 0 you are on fresh water and see your capital producing a lot of hammers by Printing Press from say lots of fresh water hills and mining luxaries, then it's looking really good for a cultural victory.
If instead you see yourself with massive flood plains start with some luxury type that provides gold instead of hammers and most of the desert is flat then science victory is a better option.
On the margin, pantheons providing culture will help a cultural victory after Hotels as would Japan's fishing boats. (Same applies to Monasteries with Wine or Incense)
For science victory, early on the AIs generally hate the idea of Science Funding, so its not as important to have the world congress early. However, after mid game the AIs often start preferring science funding which is when this can be safely proposed to squeeze one more Great Scientist out.
Civs with Hills bias: This tends towards a high hammer start which leads to cultural victory.
Iroquois (who leaves the forest intact) : Their normal problem prior to the introduction of cargo ships and caravans to getting their capital big enough to work all the hammers has been food driven. If this is a coastal start, the food cargo ships will help it grow fast enough to easily hand build Leaning Tower for the twofer. If inland (and limited to caravans), I don't know if that is the case or not.
The other start biases are much more mixed. (Hills vs Flat), and in case of the Celts, what's underneath the forest?