Oh I understand. What I skipped explicitly writing there is, if he writes an abstraction, and defends it well then give him 10 points, if he can't defend, give him 5 points. If he doesn't write an abstraction and defends it well, then give it 10 points, if not then 0....you get the jist.

The fundamental point is, who can best figure out the requirements of the customer, and write code which makes most sense with least amount of 'future problems'.