Informally, a group consists of a number of stones of one colour, hanging together as if effectively connected. They are a functional unit on the board, occupying and influencing a certain area.
Note. I think the Japanese reading should be taiseki not ooishi. Taiseki is the reading given in furigana in a footnote definition in a book I have. Taiseki is also given in this online website glossary of terms. 大石 The same applies to the page on Japanese Go Terms. Richard Hunter.
In this game, 100 stones have been played. The following stones are commonly called a "group"
- the nine white stones in the lower left
- the three white stones in the upper left
- the black structure in the upper middle
- the black stones in the upper right
- the unmarked white stones running from the upper right to the centre
- the ten white stones in the lower right
- the black stones at the bottom form two groups that are likely to become one, if they swallow the five white stones dividing them, or connecting via one of the points a
The term group is sometimes also used to refer to collections of stones which are all solidly connected together. In those contexts where it matters, such as in rules texts or go theory, the terms chain or string are usually used instead, to differentiate this concept from the more vague group concept described above.
- Weak group and strong group
- Virtual groups
- Formal definition of group, for algorithmic and programming purposes
- Chain and string