Seki inside the bulky five

    Keywords: Life & Death

A seki that will probably never see the light of day...


Jasonred : ... why... oh, fine, I'll indulge you. I guess that this shape can come about during poor playing when there are 3 very large kos in the game. Black plays in there, White ignores... no, wait, that's impossible too, since Black's first move kills the shape... in fact, why has Black just changed killing a group into a seki???

Making seki  

Bill: I doubt if this particular situation would arise on the board, but I seem to recall this shape occurring in a more complicated situation.

Charles I've found a near-miss in a pro game (Hashimoto Utaro-Iwamoto Kaoru 1936-05-31). Clearly enough the middle stone would be the final one played (otherwise Black could kill); but White's external liberties should also be filled, or White could prevent the seki by oshitsubushi. In the game I mentioned preventing the seki might have cost one point in teire.

Black to live  

Truc I found this problem in Encyclopedia of Life and Death. While the problem is contrived, some similar position might occur during normal play.


Of course black can throw in B3 at circle to make a (very bad for him) ko, but if black has any chance of gaining from that ko white would play W2 at circle to make a different kind of seki.

Harry: What happens if White plays first at circle? If Black connects at B1, then White can play, either at W2, or to the right of W2 -- then Black dies. If Black does not connect at B1, then White immediately plays there, and Black will lose all their stones.

Bill: Harry, Black plays first, and so is already connected at B1. If White plays at circle instead of W2, we have the seki in the next diagram.


Seki inside the bulky five last edited by Bill on May 6, 2009 - 20:46
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