How to agree on dead stones in Go?

After 2 consecutive passes in a game of Go, how can two players (who may lack a common language) come to an agreement about what stones to be considered dead and removed prior to scoring? This is particularly important to online Go servers.

Agreement Proposal: marking strings

Let's assume that stones can be visibly marked as dead. After 2 passes, the players keep alternating with the following 3 choices on each turn:

Marking a string as dead, which automatically marks all other same colored strings neighbouring the adjacent empty region(s).

Disputing a string marked as dead. In this case, all markings are removed and play continues as if the agreement phase had not existed. If both players pass immediately in this continuation, then there are 4 consecutive passes and the board is scored as is without any removals.

A done, when one is done indicating dead groups. Two consecutive done's end the game with dead groups removed as agreed.


The Kiseido Go Server implements a similar protocol, but in an asynchronous manner, and without the 4 pass ending. The asynchronous nature presents a problem when the opponent manages to mark another group as dead just when we choose Done. Thus we require a confirmation of the Done, complicating the protocol. Alternation seems to be better behaved, and clocks can be kept running.

When playing with symmetric (lens shaped) stones on a real board, it's not clear how to implement the marking. Suggestions are welcomed.


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