Weekly Go problems: Week 48

Here are the weekly Go problems for week 48.

Black plays first in all problems and all solutions are labeled ‘correct’. Have fun!

Easy Go problem

Normally white A is a good shape, but here B is better. Black has a clever technique to capture two stones now.

ggg easy 48 picture

Download the solutions to the easy problem as an SGF or PDF file.

 

Intermediate Go problem

One of the basic principles of capturing races is to avoid filling shared liberties until the very end.

ggg intermediate 48 picture

Download the solutions to the intermediate problem as an SGF or PDF file.

 

Hard Go problem

Intuition is important, but in unusual situations reading is unavoidable.

go problems 48 picture

Download the solutions to the hard problem as an SGF or PDF file.

Still want more Go problems?

You can find Go books packed full of life and death problems, tesuji problems and other valuable Go knowledge at the Go Game Shop.

Discuss other possible moves

If you have any questions or want to discuss any of these problems, please leave a comment below at any time. You can use the coordinates on the problem images to discuss a move or sequence of moves.

You can also download the solutions as a PDF or SGF file by clicking the links below each problem.

About David Ormerod

David likes teaching, learning, playing and writing about the game Go. He's taught hundreds of people to play Go, including many children at schools in Australia. In 2010 David was the Australian representative at the 31st World Amateur Go Championships. He's a 5 dan amateur Go player and is the editor of Go Game Guru. You can find David on Google+ and follow Go Game Guru on Facebook, Google+ or Twitter.

Comments

  1. In easy problem, you say W better to play B instead of A, but correct shape here, I believe, is G6. After that G5 and F7 are miai for good shape. If W plays F6, as you suggested, after B F7 G6 W’s shape is worse, B’s liberty at G5 remains, and W can’t press with moves like H4 (which in some circumstances may be killing move for lower B group or at least part of it).
    I’ve seen intermediate problem in Sakata Eio’s book “Tesuji and anti-suji” and was impressed at the time.
    Hard one feels weird; unusual shape.

    • David Ormerod says:

      Hi Flandre,

      With the position leading up to the easy problem, choosing between white F6 and G6 can be quite difficult. It depends on what other stones are nearby, but G6 can sometimes be a terrible blunder, whereas F6 (while being bad shape) is rarely that bad. Because, like many things in Go, the answer is ‘it depends’, I wanted to avoid confusing people by saying ‘move x is always best’ and just show a reasonable alternative to the attachment.

      If white plays G6, she has to keep in mind that black can choose to squeeze with F6, F5, G5, F7, F4, F5 and then black can extend to E8. In this case, it’s not that bad because white’s already alive in the corner, but it’s important to know that playing G6 gives black the potential to cover the weakness at F3.

      If white thinks that black’s going to play the squeeze, then she might decide to simply play F6. It’s bad shape, but it also avoids helping black to make shape. After F6, if black pushes from behind with F7, white will be grateful to just extend. Yes, white is being forced, but black will have to do something about the cut at D7 eventually and then white can play first on the lower side. The further black pushes white into the center, the more severely white can play later.

      Thanks for bringing this up. You gave me some good ideas for some other problems :).

      • Reasonable. Though main trouble with G6 is may be that suggesting it in commentary immediately hints how to solve actual problem, making it even easier -_-
        Oh, and example of “good empty triangle” is also very nice for kyu players who sometimes too much believe in “good shape” and refuse to play what position requires them to.

        • David Ormerod says:

          Good point, one of the only criticisms I have of the Lee Changho Life and Death books is that quite a few problems say things like “black should have played at A,” and immediately draw your attention to the vital point. Even if you can’t read the text, there’s still a mark on the board. Apart from that they’re excellent.

          I’m sort of a fan of bad shape tesuji, because they’re interesting exceptions to the rule and they’re often powerful moves that are overlooked. I’ll try to come up with some problems like that.

  2. Hello David, The hard one is hard to me… I will keep on trying it!. I very like the intermediate, black 3 at A5 is a surprising move .

    • David Ormerod says:

      Hi Jangalf,

      The hard one is really strange :). The space isn’t that big, so if you keep trying you’ll get it eventually. In my opinion, regularly solving problems like the intermediate one is more useful because that sort of situation can potentially occur fairly often and knowing black’s first two moves speeds up your reading a lot. The hard one is just a test of your reading, so I don’t include those sorts of problems too often.

  3. Great intermediate problem, but there is no way I can read this in an actual game.

    The hard problem is more “natural” it can be done without “reading” all posibilities.

    Thanks a lot!

    • David Ormerod says:

      Right Damián, I remember having trouble with something similar to the intermediate problem the first time I saw this sort of idea too. But now that you’ve seen that this is possible, you’re much more likely to see it if this ever happens in your games. To some extent that means you don’t need to read, because now you ‘know’ ;).

    • The hard problem is a classic one for inverting the move order in analysis.

      What I mean is, instead of looking for the first move, imagine white getting a move on some vital point then you get 2 moves in a row. The end result is that ONLY the ways you can succeed with two moves in a row after that PLUS the move on that vital point can be the first move. Nothing else need be considered.

      The simplest example (as here) is when you can read that if white gets a certain move in, 2 moves are no use. Then white’s first move is your only option.

      The second simplest is if there is only one pair of moves that work, say A and B. Then the only 3 moves to look at are A, B and (not to forget it!) the move you allowed white to start off with.

      Even more choices can still be helpful if you can discard some options quickly. The trick is to find a vital enough point in a problem; and if there is none to reject this method of reading.

      • Younggil An says:

        That’s a nice explanation Hippo.
        That theory is quite useful to know, especially when you have difficulties to find a right move in life and death situation. :)

  4. The hard one is quite hard for me that I only got almost correct with a ko (打劫)!

  5. Hey! I did it! But there’s still a ko!

  6. Hi. I solved the easy and the hard problems but I’m having trouble on the intermediate problem. Couldn’t you play this sequence of moves(in the intermediate problem): B4-B5-B3-C6-A6-E7-A5-A6-A7-A8-A9-A8 and then capture at B6? If not, can you explain why? Thanks.

    • David Ormerod says:

      Good question Tan. After white play E7 in your sequence she’s ahead by one liberty in a capturing race. Black can keep taking liberties and connect along the left side, but white will have time to play E5 and E6 and will capture the four black stones.

      There’s a way for black to save the four stones by trading for the corner or winning a capturing race (if white is stubborn). In some situations it could be better to connect along the edge and sacrifice the stones in the center. It would depend on the relative size of the corner and the isolated center group.

      The point of this problem is just to show you that there’s a technique to save the four stones, but in a real game there are many more things to consider and (after seeing that black had these tesuji available) you’d still have to decide whether it was worth saving the four stones or not.

      That’s one of the differences between practical play and the isolated world of Go problems :).

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