Analysis of information sources in references of the Wikipedia article "Rules of Go" in English language version.
Area counting may only be used by prior agreement between both players. It will give exactly the same game result as the Territory Counting rules above.
This appendix shows that with normal play, under the given rules the "area" and "territory" scores of a game will always be the same.
Around year 700, when the Chinese were still using territory scoring, go spread to Japan, and so the Japanese also came to play go with territory scoring. The Japanese then gradually altered the rules of the game, for example abolishing (...) the group tax.
[Group tax] was a byproduct of stone scoring: originally, only living scores counted towards a player's score, so in the end the board was filled with stones; but every group has to leave two empty intersections for its eyes. Therefore, when the 'group tax' applies, every group costs a player two points.
Therefore, when the 'group tax' applies, every group costs a player two points. This rule made the territory scoring process more convoluted, which is probably the main reason why it was abolished.
This is stones scoring. In fact this rule was in use in China until the beginning of the last century (ang.).
So around the mid-Ming Dynasty, a new way of counting was invented: unilateral stones-counting on the overall 361 points. The total number of points on the board is 361, and we can count the total number of the stones and empty territory by one side, and compare it with the number 180.5. To be sure, eye points will have remained discounted, and in practice the score will have been amended with the difference between the numbers of both strings of living stones.
