My answer was
at F1, and a 
response at E1 shows as wrong. But capturing with 
at E2 strikes me as a perfectly valid solution. What am I not seeing?GoChild Problem
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ninestone
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GoChild Problem
I'm going through the problems on GoChild, and it marks my answer as wrong but I can't see why. The problem is #98 of the Basic 900 Connect and Cut pack:
My answer was at F1, and a response at E1 shows as wrong. But capturing with at E2 strikes me as a perfectly valid solution. What am I not seeing?
My answer was
at F1, and a response at E1 shows as wrong. But capturing with at E2 strikes me as a perfectly valid solution. What am I not seeing?-
Magicwand
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Re: GoChild Problem
"The more we think we know about
The greater the unknown"
Words by neil peart, music by geddy lee and alex lifeson
The greater the unknown"
Words by neil peart, music by geddy lee and alex lifeson
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daal
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Re: GoChild Problem
E2 makes a ko. This gives white a chance to keep you separated and kill at least one of your groups. There is a better answer. 
Edit: which you can see above, if Magicwand doesn't hide it...
Edit: which you can see above, if Magicwand doesn't hide it...
Last edited by daal on Thu Feb 24, 2011 1:46 pm, edited 1 time in total.
Patience, grasshopper.
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quantumf
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Re: GoChild Problem
ninestone wrote:I'm going through the problems on GoChild, and it marks my answer as wrong but I can't see why. The problem is #98 of the Basic 900 Connect and Cut pack:
My answer was
ko
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ninestone
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Re: GoChild Problem
I saw that it's ko. There are no threats for white so the only response is to connect at E4. Maybe I just have an aversion to calling the solution wrong just because it's not exactly what the author wanted. And capturing 5 stones is optimistic when white can connect after the peep (that's another solution GoChild accepts).
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Chew Terr
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Re: GoChild Problem
9stone:
With ko in go problems, you have to assume that there MAY be threats elsewhere. For that reason, ko is worse than life. And for this connection problem, if you can connect without ko, it's superior to ko. So gochild is hoping for something like this, as 'ideal for both sides'. If W could separate black, W could kill at least one side by making it a dead shape. However, by connecting, black saves both. White can't play 4 @ 5 because then she would be in atari.
With ko in go problems, you have to assume that there MAY be threats elsewhere. For that reason, ko is worse than life. And for this connection problem, if you can connect without ko, it's superior to ko. So gochild is hoping for something like this, as 'ideal for both sides'. If W could separate black, W could kill at least one side by making it a dead shape. However, by connecting, black saves both. White can't play 4 @ 5 because then she would be in atari.
Someday I want to be strong enough to earn KGS[-].
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daal
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Re: GoChild Problem
ninestone wrote:I saw that it's ko. There are no threats for white so the only response is to connect at E4. Maybe I just have an aversion to calling the solution wrong just because it's not exactly what the author wanted. And capturing 5 stones is optimistic when white can connect after the peep (that's another solution GoChild accepts).
It's not that black can necessarily capture stones, but if w connects after the peep. black connects and is unconditionally alive. Usually when doing this type of problem, we assume that there are ko threats elsewhere, even if they are not shown on the diagram, and if it's possible to survive without ko, then that's better.
Patience, grasshopper.
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ninestone
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Re: GoChild Problem
These connect and cut problems make me feel like I'm too stupid to play Go. I nailed everything up to them, and now I don't get any.
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Chew Terr
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Re: GoChild Problem
ninestone wrote:These connect and cut problems make me feel like I'm too stupid to play Go. I nailed everything up to them, and now I don't get any.
Oh, don't worry, they're really tough. If you have a bad time with them, you can always work on a different set and come back later. That set and some of the endgame sets are particularly merciless.
Someday I want to be strong enough to earn KGS[-].
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judicata
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Re: GoChild Problem
ninestone wrote:These connect and cut problems make me feel like I'm too stupid to play Go. I nailed everything up to them, and now I don't get any.
Starting out, I found "connect and capture" and shortage of liberties problems to be difficult to grasp at first--keep practicing and you'll get the hang of it.
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Shaddy
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Re: GoChild Problem
I looked at the connect and cut series and got a few of them wrong on the first try, and then I ｒｅｃｏｇｎｉｓｅｄ a problem from what I ｔｈｉｎｋ ｗａｓ ａ ｄａｎ－ｌｅｖｅｌ ｐｒｏｂｌｅｍ ｂｏｏｋ． Ｓｏ ｄｏｎ＇ｔ ｇｅｔ ｄｉｓｃｏｕｒａｇｅｄ， ｈｅｈ．．
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Bill Spight
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Re: GoChild Problem
ninestone wrote:I saw that it's ko. There are no threats for white so the only response is to connect at E4.
Not so, as I shall show below.
Maybe I just have an aversion to calling the solution wrong just because it's not exactly what the author wanted.
Oh, go players are quite aware that a problem may have multiple solutions. That is not the case here. There is only one solution.
And capturing 5 stones is optimistic when white can connect after the peep (that's another solution GoChild accepts).
It's not another solution, it's another variation. For Black to have a solution, it has to work for every reply White could make. In fact, capturing the 5 stones is the key variation because Black has to see the tesuji combination of throwing away three stones to reduce White's liberties. GoChild should not really accept a solution that does not include that variation. (IMO, it should not accept a solution without both variations.) In real life, White should not choose that variation, but this is a problem for Black, not White.
WHy is ko not a solution? First, because it is unsure. If there is a sure way to kill or live or connect or cut, ko is not the solution. (Sometimes double ko is the solution, if it provides a sure way.) One reason for that is that you may lose the ko in real life. The problem does not show the whole board, so we do not know the ko threat situation. (Oh, looking at the diagram, perhaps GoChild shows the whole board. It should not. If this were the whole board, Black could resign.
) Let me illustrate the other reason below. connects. White can save and 
as ko threats. elsewhere is the correct response (almost regardless of the rest of the board) to . The ko is humungous, and in real life White will not have a ko threat that Black should answer. But White should make the ko, anyway. Making the ko forces Black to make two net plays to connect instead of one. White sacrifices a few stones for an extra play somewhere else. (It is conceivable that there will be no play big enough elsewhere for White to make that sacrifice. However, the possibility that there is is enough for not to be part of the solution when Black has a sure connection in one net play.) The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins
Visualize whirled peas.
Everything with love. Stay safe.
At some point, doesn't thinking have to go on?
— Winona Adkins
Visualize whirled peas.
Everything with love. Stay safe.
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lefuet
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Re: GoChild Problem
beginner - ko - problem 140
i think there is no need for ko to live or am I missing smth?
i think there is no need for ko to live or am I missing smth?
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Magicwand
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Re: GoChild Problem
lefuet wrote:beginner - ko - problem 140
i think there is no need for ko to live or am I missing smth?
i dont see any way to kill this group
"The more we think we know about
The greater the unknown"
Words by neil peart, music by geddy lee and alex lifeson
The greater the unknown"
Words by neil peart, music by geddy lee and alex lifeson