1.21
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I spent the rest of my game, from 680AD, pursuing two goals at once: expansion and space.
On the expansion side I attacked one Civ after another until I was near the domination threshold. I used just Cavalry in all these wars, plowing through Riflemen, and in some later cases a few Infantry, with sheer superior numbers. Cavalry on their own have one great advantage - they can be used from a distance, causing less war weariness.
I'd previously taken over Germany, Minoans, Russia, and France. I hit Ottomans next, with some concerns since she had Sipahi. No problem, they were gone in 740AD. Next came Celts, gone in 800AD. I finally built a few boats, attacked Hittites, and reduced them to one remote city in 870. Next Egypt, gone in 910. I started for Babylon but Zululand attacked me at this point so I hit Zulu and Babylon at the same time, buying an alliance against Zulu from Carthage to reduce the pressure. Finished off Zulu in 1010, Babylon in 1040. And that was it on the expansion front.
The research side of the game was more complicated.
At the start of the Industrial Age I'd guessed that the AI's wouldn't be able to learn any further required techs. But after a while I decided to try it anyway. I was confident I could maintain four turn research for the rest of the game. The only way to improve my finish date would be to squeeze research out of a rival. I laid out the ambitious goal of getting two required IA techs out of them. Since they were still working on Nationalism (BTW, I don't think it makes a big difference if that's one's free tech or not - if it is, the AIs can work on other stuff, if it isn't they'll fixate on it first, losing one other tech they might have worked on), and I'd just learned Replaceable Parts, that determined my plan. I picked Spain, Zulu, Persia, Carthage, and Rome as potential helpers. I gave them luxuries and didn't take any more of their gold. I gave them Electricity so they'd start on Replaceable Parts if they finished Nationalism. I researched to Combustion and then gave my helpers Combustion and Replaceable Parts, hoping they'd go for Mass Production and Flight. I finished off the bottom techs with fingers crossed.
The plan partly worked - Spain learned Mass Production for me. So that was one useful tech gained. But that was it. I'd been watching AI research rates for some time. Spain was my best helper. None of the others had much chance of learning Flight before I had to do it myself.
So, time for a new plan. Could I get a Modern tech from the AIs? It would be hard to direct them there, with one exception - Computers. I hadn't used my Golden Age yet. If I didn't get Computers as my free tech, I could leave 24 turns for the AIs to learn it and use my Golden Age to maintain a four turn rate without labs. I decided to go for it. I timed ToE to complete when I learned Motorized Transportation, in 960AD. I took Flight as my first ToE tech, got Fisson as my new era tech, and took Ecology as my second ToE tech.
I swapped a prebuild to complete UN in 1010. Selected Spain and Persia to be my only remaining helpers (Rome and Babylon were too slow, Zulu had declared war on me.) I gave them the required techs and a few hundred gpt. MPP'd them both. Kept them fully stocked on luxuries and resources from that time onward.
First they learned Amphibious War and Sanitation. I chewed my nails. Finally, Spain learned Computers one turn before I'd have to start it myself, phew!
So that knocked another four turns off and I launched the spaceship in 1240AD.
Here's my world map at that date:
This sure was an interesting game! I did a lot of things which were unusual for me:
o Started out very slow, a long time till I began pumping settlers.
o Didn't use any boats until the Industrial Age.
o Skipped some wonders I usually treat as important, e.g. Smith's, to avoid an unwanted Golden Age. I even abandoned a number of unwanted wonders in captured cities.
o Delayed my Golden Age until Modern Times.
o Attacked Infantry with unsupported Cavalry.
o Had few leaders - I hung onto one for a long time to have flexibility in quick changes of plans. Never did use him

o Supported a couple of AIs with large gold donations.
I think I did it the hard way, that it was a mistake to defer my Golden Age. If I'd taken it very early, while in Despotism, I think I could have gained more turns than the four I got by using it in Modern Times, and with a lot less work. Initially I delayed it to get into Republic and to have two core areas which would benefit. And ever after that, I kept delaying it for a rainy day since I didn't need it yet.
I also have the feeling I might have squeezed one more IA tech out of the AIs if I'd focused on that all along and done it right.