I'm assuming readers know how to play isolated starts, if not I think there's some guide in one of the lonely hearts club pages. Even if you narrow it down to beelining astronomy, there are a lot of different plays. Some people like to go for great lighthouse, or great library if they have marble. Some people will go for monarchy and build up a huge academy capital. My personal rule is that you have time to detour into one classical tech, so it better be the best tech for the situation. --- So let's talk about the worst case scenario for an isolated play, not including weird one city spots. -You have no extra happiness. Happiness often dictates how you play an isolated start. If there's a lot of calendar resources, well you go calendar. If there's a lot of precious metals, you can skip non-beeline techs and rely on gold happiness with the occasional forge. Even if you just have some hunting happiness resources, it's often enough to make an academy in your capital worthwhile. So instead we're stuck with a 5 happiness capital. -You have no wonder resources. Of course if you can get stone, you can representation, which means happiness and extra beakers. If you have marble, you can often fail gold parthenon, so you can skip alphabet and dump hammers into wonder hammers instead. And you can get great library. -You have poor isolated traits. No charismatic, no philosophical. I did my test cases with tokugawa, just to make sure I didn't even get discounts on anything. So if it works for him, it works for everyone. What you do have some food resources (enough for at least 3 cities without sharing food resources), some riverside tiles, and some hills. What's the best way to to get fast optics/astronomy? Planning You need 3 fast libraries of course, to get fast astronomy. However, 2 size 4 cities and a size 5 aren't going to produce nearly enough beakers to in time. Academies aren't very useful. Especially when you have seafood + one riverside tile. Granaries aren't useful for size 4 cities. Whipping doesn't create commerce, and not being able to work a tile for ten turns costs you at least 37.5 beakers. Libraries (outside of your 3 core cities) may or may not be useful. If you have too much food, then you either have to stall by pumping workers/settler, or build a library. The earlier you get the library, the more time it offset its cost. So if you haven't guessed, this means that we're going to be building mostly research. Our early extra food (after the libraries) we dump into more cities, which we will use to build research. Food->hammers->research. Micro details Usually we save gold until we have our academy. Since we're not building an academy, it's probably better just to save gold until two or three libraries are up. When saving for multiple bulbs (without caste system), it doesn't matter much how fast you get your earlier great people. It only matters when you get your last one. Hence the fastest way to get multiple great people is to complete your libraries as close as possible. You can delay running scientists in your earlier libraries in favor of more worker/settler production. Since we're saving our first great scientist for optics, this means we can delay the first two libraries so they finish close to the 3rd. Unless you want to gamble, you usually have to wait quite a few turns for your caravels to find most of the civs. Which means you can delay your 3rd (and hence 2nd) great scientist so that it finishes a handful of turns after you get optics. Cottaged riverside plains tiles are your friends. Especially once you complete your great person, you can switch off to cottages, though this usually means you end up with too much food. Plains tiles help defray the extra food. Riverside hills also have high value. Sample game: There's silver, but I pretended it didn't exist. Spoiler optics : Maybe with further refining, speeding up my 3rd library (and slowing down the previous two), and better use of plains tiles, I could shave off 2 or 3 turns.