Dan Nelson.

If you ever wondered about mana bases and mathematics in limited you should read these:http://www.starcitygames.com/tags/DanNelson/2002-09-20/2014-08-15

Included (not all in the same article)
* why 2 land hands suck, and should generally be mulled (especially on the play) - also general mulliganning (land based!) guidelines
* why cards above 6 mana are unplayable
* why you CANNOT splash for double colored cards
* why 2 mana gold cards like are harder to cast than cards like
* by what turn you can expect to be able to play cards of cost X
* why you should play 10/7 land splits with costs like CCX

Good stuff.