Japanese Rule Sharpness

This page aims to provide a simple position in which Japanese Rules are “sharper” than Chinese Rules, where (as indicated in the article Sunjang Baduk Counting) a rule set ``R`` is considered “sharper” than another rule set ``S`` in a certain position if fewer moves are optimal in that position under ``R`` than under ``S``.

Table of contents Example Analysis by Bill Spight See also

Table of diagrams Black to play Correct play White takes ko Incorrect play

Example

Example:

Black to play  

Analysis by Bill Spight

Bill:

Correct play  

is a 1 pt. sente, threatening to kill White. gains 1 pt. Black wins by 1 pt.

White takes ko  

In the potential ko fight, fills the ko with sente, threatening to kill Black with a throw-in at 4. If throws in at 4, Black takes the ko and wins it. If White were komaster, would fill at 4, and the ko would be a 1⅔ pt. White sente.

Incorrect play  

gains 1 pt. and then the reverse sente, , gains 1 pt. The resulti s jigo, 1 pt. worse for Black.

See also

• The discussion section in Chinese Rule Sharpness