Below is problem 1 and solution from Graded Go Problems for Beginners Vol. 3. Can someone explain why black need not worry about white cutting (and atari) at the double hane? And the solution even specifically states that white ends in gote, implying that black still doesn’t need to worry about that cutting point after white 4. I guess a white cut there might not be that big of a deal (depending on surrounding situation) but it just seems like it would be easier for black to protect, but at the cost of losing sente I guess.
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I remember finding this puzzle also a bit tough to understand when I first came across it. I think move 1 is the most important anyway for shape. The rest can be details.
For black in the solution, I think in most cases the five black stones in the centre are fine and have a lot of liberties and room to jump to the centre.
There’s a good chance white also needs to defend the top group before being able to make a cut like the push and cut near the 4-4, but even then the black stones are resilient and can atari underneath.
Generally if black only had to handle one set of weak stones here it should be manageable, and it might be tough for white to make multiple cuts and not be very weak themselves with the cutting stones.
There’s two things black’s hane achieves. One is it lowers the liberties and creates some follow-up moves the white can’t really ignore, and giving white some shape problems to deal with. If you ignored black 1 in the solution, another atari either leaves white quite low on liberties or could potentially capture the three stones in the middle. Or ignoring 3, then Black playing at 4 is an issue. So it’s hard to ignore.
The other related idea is that it confines white more or less in sente on the side, which is the point of the puzzle.
So 1 is probably a good move fairly often in many board positions, but I think it depends a little bit as you said on surrounding stones for the continuations and there’s other variations white could try like playing two Ataris before making a tigers mouth.
As is though in the book, once white is forced to live, black can take sente and potentially even give up the two stones (1 and 3) on the side now. It’s not going to make white more alive. If it’s not going to turn into a large upper white territory, then black can give up those 5 or 6 points and take sente again in some situations.
Some examples to show different scenarios:
- Where Black 3 in the correct diagram is a bit too much
Still even enough but black needs to squeeze the white stones a bit.
- You can probably give up the two stones if the cut at A below, and resit the cut at B
- Theres other cases where the cut isn’t that important. Cutting and extending wouldnt be great here
In some scenarios white might rather this sort of endgame to be available at a later stage and leave the cut for that.
- A push and cut, but this move is kind of annoying for white
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Excellent reply—thank you! I especially appreciate the diagrams with the various “what if white cuts?” scenarios.
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You definitely want to train your shape intuition to double hane at 1 here, that’s most important lesson. And then cover at 3 seeing the shape point attack at 4 inside next. But you are right to think about the cuts, and the explany words in the book about 4 gote are kinda wrong. White doesn’t absolutely need to defend at 4 to live, if they cut and extend like shinuoto’s 4th diagram then j19 being sente is enough to be (barely) alive. But this is a bit beyond the basic beginner shape lesson purpose of this problem. Also quite often black taking gote to defend the cuts could be a good move, depending on the position in top left area.
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