AGA Passing on OGS

Hi, I am wondering if there’s any difference in the way that passing is processed on OGS using AGA rules as compared to Chinese rules. I notice that the flag for “white_must_pass_last” gets set to true for AGA rules on OGS, but in practice I’m not seeing any difference in ending a match with black or white passing last. After two passes of any order, the game goes into the stone removal phase and once both players accept the stones the game is over. In the AGA rules it mentions that for each pass, the opponent takes a passing stone as a prisoner, but in AGA scoring, prisoners don’t get counted towards/against the score, so I am wondering what is the point of them, or if it only matters when playing over a physical board. I feel like I must be missing something and want to make sure I implement it correctly in my game. Thanks!


The AGA passing rule and passing stones are only needed when you intend to use territory scoring (these rules make the territory score difference equal to the area score difference).
When you use area scoring, these passing rules are redundant.


Thanks, Gennan! So for the purposes of OGS, since it uses area scoring for AGA, the passing rules can be ignored. Maybe that flag for white passing last was put in place just in case territory scoring on OGS would ever end up being used for AGA rules in the future.

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I think in real life AGA games, people commonly use territory scoring because it’s more convenient.

Maybe it’s only in the OGS source code for reference, or for completeness in case people insists on using AGA territory scoring on OGS.


Makes sense. Thanks again for your time!

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