First of all, I would point out that the situation in that screenshot only applies if you are running an Agri civ (i.e getting 3FPT from the city-tile), or if your farm has at least one +1f bonus-tile(s) (e.g. Wines, or Sugar) in its BFC. If neither of those points apply, then you can't actually keep a Pop6 or Pop12 farm running at 0FPT net, even on fully-irrigated grass -- you will have a deficit. Before rails: Pop6, with 3 Scientists, food-output = (3*3 + 2) - 12 = -1FPT Pop12, with 5 Scientists, food-output = (7*3 + 2) - 24 = -1FPT After rails (adds 1FPT to irrigation), you can run 3 or 6 Scientists, but with a food excess: Pop6, with 3 Scientists, food-output = (3*4 + 2) - 12 = +2FPT Pop12, with 6 Scientists, food-output = (6*4 + 2) - 24 = +2FPT If you're running your farms at that level, you'll be wasting 2FPT per town, which could be feeding someone else. So you could run 1 more scientist in each size town at a deficit again, but the deficit will be higher (i.e. the food-box empties faster): Pop6, with 4 Scientists, food-output = (2*4 + 2) - 12 = -2FPT Pop12, with 7 Scientists, food-output (before rails) = (5*4 + 2) - 24 = -2FPT Either way, getting the absolute maximum BPT out of any town would require careful MM: by sending a Scientist back out to work the fields when the town's food-box gets down to 1 or 2f, you can then refill it (at a rate of +1 or +2FPT, but 3BPT fewer per town). But if you accidentally allow the town to starve (because e.g. you forgot to check the 'Town-about-to-starve' option in CivAssist's Alert-screen), you will then need to regrow the town from Pop5 (or Pop11), and refill the box again at Pop6 (or Pop12), wasting 6-7 potential beaker-production turns. In terms of BPT output, you're absolutely right that two Pop6 towns running at negative FPT (3 or 4 Scientists per town, i.e. 6 or 8 Scientists per 12 citizens) will give more BPT than one Pop12er (5 or 7 Scientists per 12 citizens). But in terms of MM, Pop12 towns are certainly better than Pop6ers -- because their food-boxes are twice as large, they'd only need reassignment every 39 turns before rails (every 19 afterwards), instead of every 19 turns (or 8 turns after rails). But personally, I have never been interested in optimising my games to the nth degree and finishing in the absolute minimum number of turns, and frankly I can't be bothered with (read: am too lazy for) that level of MM. It's certainly not necessary for a win at Monarch, nor at Emp (and I suspect not often at DG either). In the above Chinese game, where I didn't start farming in earnest until I'd got Steam/rails (i.e. early Industrial Age), I found it simplest to keep the grassland farms at max. Pop 5 or Pop11 with 3 and 6 Scientists, respectively, for 0 FPT and no further MM. While doing so sacrificed the potential extra BPT (while the food store is being used up), it also significantly reduced IBT processing time -- and tedium -- because I didn't need to fiddle with 10-20 farms per turn, every turn. And my now-decided preference for 1 big farm rather than 2 small ones is aesthetic as much as anything. Having now produced a whole map of CxC cities (I can post a screenie if anyone's interested...), I confirmed my previous suspicion that I would find such a map extremely ugly.