Daniel Leader's Pain Au Levain

I believe this is the same recipe in "Bread Alone" which he calls "Basil's Pain Au Levain". Anyway, this is the recipe I've most recently been following, and it is really no more clearly written than the one in Bread Alone... http://www.foodnetwork.com/recipes/my-personal-favorite-pain-au-levain-recipe.html

Anyway, if anybody is struggling to decipher this recipe, I think I may have cracked the code. The problem for me arises (heh) from his instructions for creating the chef. Well, it's a 100% starter, isn't it? Anyway, he gives very detailed instructions for building it in 3 days. However, if one adds up all the measurements of flour and water for each day, one ends up with 24 ounces of chef -- to which he then instructs to add 6oz of flour in order to make EIGHTEEN OUNCES of levain. I want some of his anti-gravity flour.

Okay. So to get eighteen ounces of levain, one should use 12oz of chef (assuming the amount of flour to add to it is correct...) Oh hey, that's half of 24oz. Which brings me to my theory that he simply forgets to mention that you may want to keep half in order to propagate what is essentially a starter (even though he even more confusingly refers to the levain as a "levain starter"... really???)

Ideas, opinions? A few times, I was able to somehow successfully make this bread before I even owned a scale probably because I just intuitively kept adding flour until I could actually handle the dough... Then I learned to slap-and-fold and ended up making slightly salty, but very tasty and flat quasi-ciabatti...