score calculation

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tom
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score calculation

Post by tom »

Hi,
In the following 9x9 board:
Image

I (black) lost by 11 points.
I'm not sure I understand the way the scored is calculated, because the total area I have is 24, while white has 23.
Does white get +1 for each of my stones in his area? this might explain it.

Thanks!
Uberdude
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Re: score calculation

Post by Uberdude »

tom wrote:Does white get +1 for each of my stones in his area? this might explain it.


Yes. The dead stones of yours within his areas are removed from the board and added to his captures. Each capture is +1 point, so he gets that plus the 1 territory. (in Japanese rules)
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Re: score calculation

Post by Tryss »

But you need to also count the other stones captured during the game too
tom
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Re: score calculation

Post by tom »

Got it. Thanks!
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Re: score calculation

Post by Pio2001 »

Hi,
In japanese rules,
Black score = Black territory + black's prisoners + white dead stones inside black's territory
White score = same thing (reversed) + komi

In chinese rules
Black score = Black territory + number of black stones on the board
White score = same thing (reversed) + komi + number of handicap stones

In AGA rules
Definition 1:
Black score = Black territory + number of black stones on the board
White score = same thing (reversed) + komi + number of handicap stones minus one
Definition 2:
Black score = Black territory + black's prisoners + white dead stones inside black's territory + pass stones given by White
White score = same thing (reversed) + komi
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Re: score calculation

Post by Vio »

It's a good example game for understanding the rules.

In Chinese you simply count all and you don't care of prisoners.
Here a quick look you see white as a whole (stones and emptyness inside) is bigger. He took like all the middle line more. He wins
(By 9+komi)

Now comes the Japanese rule, which try to be a bit more elegant by counting only the emptyness inside. How can it work?
Well if you consider that we are going to play the same quantity of stones (we alternate plays) we can afford to forget the boundaries.
To make it working, we will now have to put back the prisoners on the board (so we will still have that same Quantity of stones played)

Indeed these prisoners will lower the points of black here and then... magically you will find the same score in both rules!

Well here there is not the same quantity of stones played (there is a difference of 3) so my guess is black did capture 3 white stones which we don't see. After putting them back on the board with the black prisoners too, you then get the same number of stones played and then... The same score as in Chinese.

Last note to explain the equivalence (read it only if you still don't have a headache):
In Chinese a empty point has same value (1) as a stone so you can add or remove stones it will give the same score as long as you don't perturb the boundary. So you can have the same quantity of stones played for each colour and so you indeed don't care either on prisoners, and so you can build the equivalence with the Japanese rule.
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