Quote from Creevy »I definitely agree with you that the deck needs to be consistent and statistical in order to properly function. As an alternative thought, I use this article by Frank Karsten when it comes to hitting my colors: https://www.channelfireball.com/articles/frank-analysis-how-many-colored-mana-sources-do-you-need-to-consistently-cast-your-spells/
According to this, as long as you have at least 14 sources of a color, you should be pretty statistically fine. Maybe one more is ideal, because he does his calculations under the assumption of 24 lands and we use 18-20.
I wouldn't fudge Karsten's numbers when making deck-building considerations. Instead, use his methodology with your land count to see how many colored sources you need.
Also, note that 14 G and 14 W is not adequate even in a 24-land deck since his guarantees are one-at-a-time. I.e., if 14 G gives 90% to find it in your opener (or whatever % and whatever metric he used), then 14 G and 14 W does not give 90% to find W and 90% to find G. In fact, I think he has a table for double color requirements, so if you want a R/W land and a R/G land by turn 2, I think he recommends 20 total sources of those colors, which is many more than the 16 you'd have separately (assuming 12 fetches, 2 of each shock, say).