# Determining who has won is very hard?

I’m assuming the game is played under Japanese rules.

1. If the players pass in this position, …

2 … the next step is to remove dead stones. Dead stones are stones of which both players agree that they can’t avoid being captured.
For argument’s sake, I assume that both players agree that the marked stones below are dead and all the other stones are alive (that assessment is not neccessarily correct[*], but that’s OK as long as the players agree):

1. When all dead stones are removed and added to the prisoners, we arrive at this situation:

1. Now we determine which regions of the board are fully closed off by stones of one color. In this position, we can find these regions:

1. The triangles mark white territory and the squares mark black territory. I count 8 points for white and 10 points for black. Besides this, white has an additional 5 points for the prisoners added in step 3. Also, white gets 6.5 points to compensate for black playing the first move of the game (this compensation is called “komi”).

2. So in total white has 8 + 5 + 6.5 points = 19.5 points, while black has 10 points. That means that white wins by 9.5 points.

That being said, more experienced players would not pass in the original position, because both players still have opportunities to close off more territory than displayed in my diagram of step 4, so they would do that before passing.

[*]The players may not actually agree on the dead stones that I marked in step 2. Experienced players would assess black’s group in the upper right is also dead, and also white’s group in the lower left. And the black group on the right side can be dead or alive, depending on who plays at L6 or N9 first.

If both players pass to stop the game, they can. If they agree on step 2, they can continue the scoring process as I described above to determine the winner.
If they disagree on step 2, they can resume the game to fix those loose ends.

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