Alternating play

    Keywords: Ko, Rules, Theory

In the game of Go, players alternate turns. A turn can be a move or a pass. When analysing a global board position or a local group status we assume players alternate moves.


axd: I'm not sure if there is a page that describes the procedure to follow when a group's status is contested? once the game is finished. As far as I know, in such a case, players resume the game and play alternatingly around the contested group; passing is not allowed then, as it would influence the end score. Can anyone confirm this?

Bill: This situation is handled differently by different rules. Among current official rules, AGA Rules and Ing rules have clear procedures for continuing play in such cases.

axd (13k): reading the Ing rules draws my attention to the word disputed?, see also

Question About Japanese Scoring
has lengthy discussions about what to do - I (reluctantly) decide from there that the obligation to play an equal number of moves (i.e. not passing) is not essential. But I also understand that this is a dark area of the rules. A bit disappointing for someone who thought Go was simple :-)
Japanese Counting
some procedure exists...
Japanese Rules/Discussion
use a separate board to decide on the status of a contested group
Scoring/Discussion
Bill suggests playing out, including pass stones
Territory and Area Scoring
There are territory rules that allow disputes to be settled by play, such as the Lasker-Maas rules and Spight rules.

Quite disappointing (yes, welcome to the game, I know :) ... Not quite certain, but I believe I lost a potential (and most probably brilliant) Go player because he might have had problems with such issues.

Bill: You should have played him using area scoring, such as AGA rules. Even if you are used to territory scoring, the transition should be easy for you.


On the other hand in considering play on a sub-board we can and should try to understand the effect of tenuki plays, which break up the alternating pattern. When play isn't alternating in a local situation, the balance of plays there can become one-sided (as measured by the local tally). This often happens, for example in ko fights: the ko rule prevents alternating play, and follow-ups after the ko is dissolved are common.

The same effect can be achieved on a full board by using the rules for environmental go.


This is a copy of the living page "Alternating play" at Sensei's Library.
(OC) 2009 the Authors, published under the OpenContent License V1.0.
[Welcome to Sensei's Library!]
StartingPoints
ReferenceSection
About