Hi, simple question here. I was reading some articles and practicing on my own and I’d like to confirm if these are the places where the presence of an extra black stone guarantees that the white stone will be captured (the board can be bigger, just suppose there’s a reasonable amount of empty space on both sides). Thanks!
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These are some, but not all.
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If I may chime in as a mere 15 kyu: Personally, I frequently stumbled when I would hear more experienced players say that a stone “was captured” when it was still on the board. What I came to understand is that:
- This phrase is often shorthand for something like “the stone is as good as captured in this current board state aka ‘for now’”
- Or even more perplexing to me as a 20kyu, “the cost to save the stone would be such a bad trade that you must forget about it for now”
- …Because until the stone is actually deprived of all liberties and removed from the board, it may come in handy later on
Stepping back, I think (again, this is coming from a mere 15 kyu) that this sort of phrase stems from the fact that go is ultimately about controlling territory rather than capturing stones. So, the shorthand is used because conceptually that is how a stronger player thinks about the stone: as good as captured… for now…
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Anyway such a board position never occurs, with a single white stone in atari, a fourth black stone and no other white stone nearby. Or it occurs so rarely that it’s not worth studying that position specifically.
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Fair enough, I shouldn’t have made the example on the 9x9 board (you meant “black can do”, right?").
@martin3141 Well, I forgot to mark the obvious ones to me (triangles). But it looks that the circles work too, is that it?
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Did you check any others? What sequence(s) do you consider critical in the case where no additional stone is present? Maybe looking at it will reveal other places where an additional black stone changes the outcome.
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@martin3141 It seems that this unprotected point is the problem (and the points I marked before, except the circle, take care of it):
but now I realize that Black can keep extending to the side (instead of move 4), like @Groin did, so a stone much further away to the side of my circle can still work, leading to the “Six die but eight live” position of the second line. At this point, this is just a theoretical exercise of course, since the stone becomes so far away that even an invasion is possible. Still, since that’s the answer to the isolated problem I was interested in, I guess a stone even 5 spaces away from the initial one on the third line can influence the result. Is that what you had in mind?
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Yes, even far-away points on the second line work. Some stones on the first line work.
Additionally after black extends, white crawls, black can Hane on 2nd line. Then white has the clamp. Black is forced to connect back, and white can connect underneath.
But certain stones on the fourth or even fifth line enable black to disconnect in response to the clamp.
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@martin3141 Thanks, that was very helpful. I was always thinking about White cutting from above, like N3 in your example. Other related sources I found: MAEDA METHOD Lecture by Tuerda 4Dan / Sensei’s Library - Third line capture
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