Optimum number of workers?

[Oggums]

I don't ever do a per city thing. If I don't have enough, I build some more.

Also, I always group my workers into 1-turn road/chop/mine teams (2 workers on normal speed, 3 on epic, not sure what marathon was). Sometimes it's wasteful, if you build a watermill for example, but it's easier to manage. Also the desert tiles take longer and I think you end up wasting a turn with one of the workers there, but I don't care.

So if I felt I needed more workers on epic, I'd build three and group them.

 

[Yzen Danek]

Ditto to using my workers in pairs or trios. Especially if you're playing as India.

Three different workers working on three different projects cheats you out of a few turns of actually using two of those improvements.

e.g. if it takes 1 worker 9 turns to build an improvement, and you have 3 of them to build, you can either put one worker on each of the 3 improvements, all finishing on turn 9, or you can put them all on the first one, finishing in turn 3, move them to the second one, finishing in turn 7 or 8 (including movement), and then finish the third one in turn 11 or 12. While the overall project is completed 2 or 3 turns later because of having to move, you got to use the first improvement for 6 extra turns, and the second one for 1 or 2 extras, for a next gain of 5 turns of using that improvement.

 

[ohioastronomy]

I agree on using multiple workers, but mostly late game. Early on the optimum is to simultaneously develop several cities to build/connect key resouces, and it's more efficient to connect three resources on turn 9 than to connect one on turn 3, spend several turns moving, and then the second on turn 9. The key governor in early city development is that your young cities simply can't use a lot of worked tiles. Multiworker improvements work better when you're upgrading with technology advances (windmills, watermills, lumbermills, railroads). In this case a mature city really can use all of the new improvements all at once, and the timing advantage is real.

 

[Oggums]

I wouldn't say "late" game. I start grouping them whenever I begin feeling annoyed at giving all of them orders.

Early on I micromanage just about everything.

5-10 cities later and I start slacking