Working the coast gives 11+1 base commerce or 14 beakers
Working the hill gives 10+1 base commerce or 13 beakers
Working a forest gives 9+1 base commerce or 12 beakers
Working the hill and coast gives 12+1 base commerce or 15 beakers
The magic line to get 3 beakers from the 20% bonus is at 14+1 commerce, which gives 18 beakers.
Currently it is T26, and we are at size 3, 12/26 food and 40/60 into our double speed Ikhanda. Working the 2 deers gives us 6fpt, 5hpt.
Worker-wise, our position is pretty set. With no Wheel, Pottery or Bronze Working, we can only mine our 2 hills. Well I guess we could farm our one bare grassland but I wouldn't be surprised if that has a resource on it. Still something to consider. So plan would be continue river plains hill mine, done on T28, then move to the other hill and mine it (done T33).
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Option A: Max growth. This is working the 2/0/1 grassland river, then the grass forests (2/1) till size 5
T27: 18/26, 50/60
T28: 24/26, 0/X (workboat?)
T29: 4/28, 5/X, now work the grass forest, giving us 6hpt
T30: 10/28, 11/X
T31: 16/28, 17/X
T32: 22/28, 22/X
T33: 0/30, 27/X, growth to size 5.
Working the 2 deer, the 2 hills, and a coast, that gives 2fpt, 12hpt.
If we work the 2 deer, the river mine and 2 coast, that makes 2fpt, 9hpt, and the 14+1cpt to give us 18bpt.
I guess we need to figure out Sailing time in all this. My spreadsheet says that Option A gives us Sailing (172b) on T38.
Let's look at it another way. We have 1 beaker overflow, and every turn gives me 12 beakers towards Sailing. Every turn working one of the river tiles adds 1 beaker, and every turn working coast adds 2, and if we work 3 coasts (or 2 coasts and a river tile), we add 1.
So by T37 under Option A, there's 11 base turns, plus 7 turns working a river tile (pre-size 5), plus river + 2 coasts + bonus for 4 turns (post-size 5). So that's 11 * 12 = 132 + 7 + 24 = 163 beakers + my overflow beaker = 164, which means that the spreadsheet is right that it will be T38. Always nice to double check results
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Okay so Option B: Max commerce. This is working 1/0/2 coasts till size 5. I'm going to ignore hammer counts for purposes of this sim.
T27: 17/26
T28: 22/26
T29: 1/28, growth to size 4, now 4fpt
T30: 5/28
T31: 9/28
T32: 13/28
T33: 17/28
T34: 21/28
T35: 25/28
T36: 1/30, growth to size 5.
T37: 4/30
So figuring out commerce as of T36, that's my 1 overflow beaker, plus 10 base turns. 3 turns of 1 coast, and 7 turns of 2 coasts So 1 + 12 * 10 + 3 * 2 + 7 * 4. 1 + 120 + 6 + 28 = 155. Next turn would be 19 beakers, so Sailing on T37.
We gain one turn (11 beakers), but we lose
Comparing the two options as of T38:
A: 10/30, 74 hammers of "stuff", 9 beakers post-Sailing
B: 7/30, 50 hammers, 21 beakers post-Sailing
So is 12 beakers (and 1 turn start on our LH) worth 3 food and 24 hammers? I don't think so. More analysis (of course) coming up....
Also T26 sandbox save attached