3.4 The Two Types of Concise and Complete Area Rules

Formulations of the two types of area rules described so far are given in Part I, together with a third type of area rules and three types of territory rules. Area rules I and II differ on whether there is a cutting bonus, and on whether points like 'a' and 'b' in Dia. 3-3-4 are counted. The situation in Dia. 3-3-4 is that White has no possible move anywhere. The chance that such a situation will ever occur in actual play is vanishingly small, so for all practical purposes, the only difference between these two area rules is the cutting bonus.*

Dia. 3-3-4

* Another scoring difference between area rules I and area rules II occurs in seki positions where one side has an eye that cannot be filled in. In reference diagram 1, area rules I deprive Black of one point in the bottom left and two points in the bottom right.

Reference Diagram 1