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Wait, please.

All the white groups are alive, in a condition known as 'seki'. See http://senseis.xmp.net/?Seki

Try it for yourself: set up the board, and play black. Try to actually kill the white groups. You will find that when you do so, you will be putting yourself in atari.

The lower left is basically seki, but is complicated by kos. I recommend studying the other two first until you have a feel for what seki means, then try it.

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Lower right:

Black has no way to play. White can make a ko, which she takes first, like this.

Click Here To Show Diagram Code

[go]$$W
$$ . . . . . . . . . . . |
$$ . , . . . . . X X X X |
$$ . O O O O O X X O O O |
$$ . O X X X X O O O 1 4 |
$$ . O X . X 5 X 3 O a 2 |
$$ ----------------------+[/go]

White can leave it on the board and black will be considered dead under Japanese rules, and will also die under other rules unless there are unremovable ko threats. Also, white has an internal threat at a

Although Herman is correct, I recommend that you study it without considering ko. In other words, just assume that all white wants to do is live. Try to figure out if black can kill white. ( You'll find out that he can't )

Later, once you have a solid understanding of what seki is, come back and look at it, asking yourself if white can not only survive but can he kill black.

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Uh, you realize that MJK is a strong player, I hope

@MJK: Where did you get the positions from? They look like they are from a rules rarities thing (i.e. the lower left is triple ko, upper left has bent four).

Different rules may produce different results, but in general these will be the results at the end of the game.

The top left is Bent Four in the Corner, and the Black stones are all dead.

The bottom right is a ko that only White can make and White plays first. So the Black stones are all dead.

The bottom left is a Moonshine Life, and the White stones are all dead.

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The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

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Nope. I assumed from the question that he was a beginner.

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The thread title question needs precision: under which ruleset? Three separate boards or all shapes on one board?

There are three different examples, which are numbered accordingly.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

Wow, this one is a doozy.

So, lets catalog:

Upper Left - Rabbity-6 vs bent 4. white can be forced to start the ko if black starts making nakade, but doesn't have to until B drops him to 3 liberties
That region is worth (Using chinese counting cuz it's easier) 35 for W or 35 for B, so 70 points

Lower Right - Similar to a bent 4, W can start the ko at his leisure. and has 1 internal threat if he starts the ko
21 points for each side- 42 points

Lower left - triple ko
20 points for each side- 40 points

The upper left is obscenely large, also, if he starts in any other position, there's no way to later involve the upper left. In order to bring the situation to a head, he has to start there. White has no advantage to tenuking so he captures the rabbity-6, and then starts the ko.

W has to find the first threat, he has 1 local (threatening for both sides to live), AAAND I'm stuck there for now, there are so many internal complications...

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Hmm... I think this was my little dumb question. I found this image in a Korean baduk website and the poster asked why it is stated in the Korean rule that figure 9 is considered dead for white, and someone replied that since white has to capture black by ko and black has 'locally' captured white, is the reason. But I found no way that black can 'actually' capture white in figure 9, so it made me ask here. By the way, it was just a careless happening that I applied this "all dead" question to other figures too, which was because in Korean, indicators of 'where's are often hidden, and by my uncareful reading I thought the poster was asking why 'all' positions in the board is dead for white, while later I did see his or her mentioning that this question only applies to figure 9. Anyway, I have just read the website of Korean baduk rules and it clearly agrees that black is dead in figure 9 and 11, for only white can attempt to capture black by ko. Figure 10 is an interesting position. The Korean rule states that "In the case of figure 10, black with an eye has the right, so he can leave it as a seki or start a repitition of kos (whole board seki tie). However, when both sides have the right by, for example a double ko, the position should be resolved in the real game or the game is a tie. (10도의 경우 집이 있는 흑에게 권리가 있으므로 흑이 빅으로 하거나 계속 패를 되풀이할 수 있다 (판빅 무승부). 그런데 다른 곳에 양패 등의 형태가 발생하여 쌍방권리가 되면 실전해결 혹은 판빅이 된다.)". I unfortunately don't clearly understand the situation of figure 10, perhaps owing to lack of my brain power or the rule's my-presumed disclarity. It was anyhow a good and rare chance to actually carefully read the go rules.

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Wait, please.

Could someone explain to me why any ruleset would rule the white in bottom left dead? (In particular: does any Japanese ruleset say they're dead?)

In the absence of positional superko (which usually isn't enforced at tournament level anyway) this looks like a "triple ko seki", since white has infinite local threats on the inside because of the double ko, so she can always recapture the outer ko.


It is a bit weird. It's a triple ko but black doesn't need to play it. Black only needs to play the double ko.

This is "Life & Death Example 8" of the Nihon Kiin Rules.

Within "status confirmation" it is necessary that a player who has captured a Ko plays a Pass, before any side is allowed to re-capture a Ko (this is -- simplified -- Robert Jasiek's version of the Ko-ban that is really correct with the Nihon Kiin Rules).

Black starts the mutual Ko-captures from above. Thereafter, White's group is in Atari, but she is not allowed to re-capture any Ko. So Black's next move will take White's group off the board.

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White to play can only initiate play in the double ko. He cannot afford to "win" the triple ko by filling it. This position is not the traditional Moonshine Life position, but nobody recorded it anyway. But they both share the characteristic that one player can initiate a triple ko, while the other player can only initiate a double ko, which he uses as a threat for the third ko in the triple ko, which he leaves open if he is allowed to recapture in it. Whether Moonshine Life positions have been considered alive or dead has been different at different times. Ing calls this a disturbing ko, with White dead. AFAIK, only the Korean rules among the main rule sets today regards this position as a possible seki.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

The top left position (#9) is quite interesting. If Black has one simple unremovable ko threat that gains B points by area scoring, which we may represent as {B | 0 || }, then normally the ko will be played out at the end with the area result of B - 35.

But along the way, as you point out, White gets a local ko threat and can initiate the ko, answer Black's threat, and get his threat in. Assuming that Black ignores it and lives, the result is -11 by area scoring. However, Black can guarantee -7 by area scoring if he can leave the position as seki. (Assuming that the rules allow that.) In that case, if B > 28 seki would be the canonical result.

Here as an SGF file.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

Thank you, Bill!

I didn't understand the whole problem until you explained it with very nicely for a Beginner like me.

Me too.

And I’d play Q 16


Greetz, Tom

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