BQM 262

    Keywords: Question

From Cho Hun-hyeon Weiqi Sucheng. Either the book is wrong or I am seriously misunderstanding an aspect of this problem. Please review and correct.

Volume 3, Problem 23

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Problem Diagram

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Book Answer

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White Alternative

After W2, the marked white group (white+circle) wins the capturing race with the marked black group (black+circle), thereby saving the white+square stones. Black does have a ladder against the two white+square stones. Are ladders assumed to be good for Black in problems of this type?

Bill: Yes, as I understand it. That follows from the assumption that all relevant stones are shown. If there is a ladder breaker, it should be shown. If one isn't shown, it's not there.

unkx80: Yes. Unless stated otherwise, Chinese books assume that the remainder of the board is empty, and hence all ladders are good for either player. I presume Japanese books make the same assumption as well. In fact, the Igo Hatsuyoron seems to take this idea a bit far, in that quite often crawling along the second line is also considered a solution for making life.

Thank you both. Yes, all the stones are shown. The book diagram only a quarter of the board.

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No ladder required?

dnerra: Doesn't this B1 do everything we want without requiring a ladder?

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No ladder required?

unkx80: I wanted to post something about this too. However, I was not able to read out completely what happens here. W6 at W10 may be another possible variation.


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