![]() StartingPoints Homepages
|
Group
One or more isolated stones or strings of stones of one colour, hanging together as if effectively connected. This is a major term used in discussion, but is informally defined only. See weak group, strong group, virtual groups. Many particular names are given to the groups which are interesting examples for life-and-death. KarlKnechtel contributes his understanding and formalism: A group of stones is a set of stones on the goban, such that
Unfortunately, the term is sometimes also used to mean something similar to the above, except that empty points are not allowed in the paths. I.e, a set of stones of the same colour, all connected to each other by orthogonal adjacency. However, it seems that the term string has become preferred for such an entity. These sorts of things may be intuitive even to beginners, but those with an interest in ComputerGo programming really need mind-boggling precision in these definitions, and it's often a lot harder to give that precision than you'd think (given that you don't have any difficulty with the concepts when you're actually playing Go ;) ). See also EyeDefinitionDiscussion. Surely this definition isn't very useful? In many games, there will only be two groups on the board (one black, one white) until late in the middle game. Thanks for the definition Karl. To paraphrase then, a maximal subset of the stones of one color connected by stones of the same color or empty points. For the definition of string or unit, just remove the 'or empty points' clause. I agree that it seems like this definition may not be useful in the early or mid-game. We may have to invoke some sort of localness condition. Again, thanks. --DaveFinlay This is a copy of the living page "Group" at Sensei's Library. (C) the Authors, published under the OpenContent License V1.0. |