The original request for this info dates back to October, but the answers are useful either way for the next person who wants to know.
A fairly
simple method to determine a fairly accurate mana ratio.
First count the number of mana symbols of each type on all the spells in your deck.
If the mana symbol shows up twice on the same card, that counts as two. (1GG counts as two)
If it is a two color spell, say B/G, then it counts one for the green count and the black count.
Once you have counted all the colored mana symbols, add the total up. Then determine the percentages of each color against that total. Let's say the total number of mana symbols is 50; 30 green ones, and 20 black ones. That makes the
simple percentages, 60% for green and 40% for black.
If we have 24 lands in our deck, then 15 of them need to be capable of generating green mana, and 9 of them need to be able to generate black mana. If using all basic lands then that is the ratio.
If you are using
Llanowar Wastes, that covers one for each. Using
Unknown Shores covers all colors, including Waste.
It isn't too complicated to determine, and it gives you a very very close curve right out of the gate.
Just don't
forget to revisit the ratios as you change out cards on your way to tuning yourself into a friend-beating machine.