OK, so I think I have this figured out. Supposing you have a granary, the difference between having an improved banana tile and an unimproved one is +2
, -2
.
1
= 1
, so if the extra 2
can net you 2
in the time it will take you to get from building the plantation to building the university, then the plantation pays for the loss of jungle pretty easily (slightly more than pays for itself, since that's +2
that you don't need to allocate a worker for).
This table is the amount of turns that +2
will save you, depending on how much you already have and how big your city is.
Code:
1FD 2FD 3FD 4FD 5FD 6FD 7FD 8FD 9FD 10FD 11FD 12FD
1POP 10 4 2 1 0 1 1 0 0 0 0 0
2POP 16 6 3 2 1 1 1 0 0 1 1 0
3POP 22 8 5 3 2 1 1 1 0 1 1 0
4POP 30 11 6 4 2 2 2 1 0 1 1 0
5POP 36 14 8 4 3 3 1 1 2 1 0 1
6POP 44 17 9 5 4 3 2 2 1 1 1 1
7POP 52 19 10 7 4 3 3 2 1 1 2 1
8POP 60 22 12 8 5 3 3 3 1 1 2 1
9POP 68 25 13 9 6 4 3 2 2 2 2 1
10POP 76 28 15 10 6 4 4 3 2 2 2 1
11POP 84 32 17 10 7 6 4 3 3 2 2 1
12POP 93 35 19 11 8 6 4 4 3 2 2 2
So, to figure out whether improving bananas pays off in science, find your city's
on the left and your current
on the top. Add the number at that intersection to the number one down and to the right (since after 1 turn, you're going to get one more
who will presumably be working a tile producing one more
). If the sum of those two numbers is greater than the number of turns it will take you to get a university out, you should build the plantation.
This is incomplete, of course; this only states whether the extra
will give you +2:c5cscience:
before the university is built. Even if it doesn't net your the extra
before that, it will still make up that difference at some point.
My conclusion: I'm probably going to convert my banana tiles to plantations a lot more often, especially if I get a sugar, spices or cotton start and end up researching Calendar earlier than I would normally.