Cut the Keima

  Difficulty: Beginner   Keywords: Shape, Tactics
[Diagram]

Cutting a keima

A keima can be cut, but the cutting stones will be cut themselves, so one should carefully choose the moment.

B1 and B3 cut White, but W4 puts B1 in a ladder. Black can change the side, and the ladder, by playing B1 at W2.


Bill: Isn't this lousy advice for a beginner? After all, the result of B1 - B3 is the same as White's extending to a crosscut.

fractic: I think the text above properly indicates that the cut has its risks and needs to be timed properly.

Bill: Well, I just did a Go Base search for this pattern:

[Diagram]

Very rare

including the empty points. There were exactly four hits. Out of hundreds of thousands, maybe over a million moves. You don't advise beginners, or anybody, to make such a play. If it is right, and they are good enough, they can find it. As for saying that a cut has risks, etc., that is asking beginners to exercise judgement they have not yet acquired. I say, get rid of this page entirely.

Yes, B1 may be often be a good play with supporting stones nearby. But not in itself. Show those supporting stones.

fractic: I agree that supporting stones do indeed make all the difference, but the diagram is just illustrating a general idea.

Out of curiosity, in your search how often did that keima appear without the black stones and no stones nearby?

Bill: I searched for the pattern without move numbers and got five hits. One was when White made the last play, not Black.

fractic: I ment to ask how often the white keima appeared by itself without B1.

Bill: Go Base doesn't just count, it retrieves references, and not all of them if there are many. It finds at least 100 such keimas, which is no surprise. :)

Dieter: The diagram is canonical and indeed needs to be immediately followed by an example of real play, justifying the presence of the keima AND the decision to cut.

Bill: It should also be explained that it is usually a bad idea. With all that rigamarole, why bother? I mean, if somebody wants to do a monograph on cutting the keima (or not), that would be nice, but it would not be a single page called Cut the Keima. Cutting the Keima, maybe, could be the parent page.

uffehellum: Cut first, think later, and smile while paying the price! Or, place a stone to break the ladder before rushing to cut the keima. We beginners absolutely should cut as early as possible. Notice that the cut is just as dangerous to white. Escaping with keima is like running with scissors. Both black and white should consider good placements of a supporting stone before the cut.


Further reading


This is a copy of the living page "Cut the Keima" at Sensei's Library.
(OC) 2009 the Authors, published under the OpenContent License V1.0.
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