What’s your mana THAC0?

At least, the article’s tables remind me of those old THAC0 charts.
Over at ManaNation.com, Dan Eckstein kicks out another useful edition of Magic: the Classroom, this time exploring the probabilities involved in drawing the cards you need given a certain number of copies in your deck, with a special emphasis on making sure you have the mana you need.
If you keep getting mana screwed, go read.