This is an experiment. Can we have a book club discussion in the forum that doesn’t give away too much of the content of the book? In that vein, I request that if you participate, please really get legal access to the book and read it. Let’s post in the spirit of fair use. That said, some diagrams will be necessary to facilitate the discussion.
On to the material:
Snapbacks can be so hard to see! The squeeze tesuji has also been really hard for me to see. And I can’t say that this chapter told me anything helpful about what to look for.
The problems in this chapter represent a wall that I have hit in playing Go. Can I get past it with focused effort?
With regard to the squeeze, there is a characteristic shape that comes up, with two right angle groups in opposition to each other, making a square. Maybe that will help me see stuff?
I still need to start rereading the chapter but the first thing that comes to mind is liberties. When you see a group down to about 2-3 liberties, I think with a lot of experience, it started to become an indicator that there’s something you might be able to do.
Even strong shapes like bamboo joints can have liberty shortages when the group they connect to gets low on liberties.
Maybe I can come back to this comment once I resume reading and read chapter 3, but I hope that’s kind of a helpful comment.
It’s something I’ve been trying to consciously work on myself is keeping track of liberties of groups while I’m reading sequences, it’s difficult, but I think it’s also a source of why I miss some things and make some bad judgements - that and many other things
I also want to highlight this in the context of what I mentioned about the last chapter when I mentioned
I do think that some books show you a lot of things but leave it up to you to really understand why, either intuitively or through experience or thought or reflection and so on.
I guess what I mean is a comment like
is telling you what you need to know in a sense but in a very minimal way, in problem 1 say - but it’s not saying that the reason it’s kind of working - ultimately ending in a snapback - is that you’re keeping the white stones to two liberties the whole time, so there’s no time for any sort of counterplay, counter cuts anything. The only thing white can do to resist is to run and try to gain liberties but it’s doesn’t work.
Don’t ask yourself too many questions.
- Try to find the solution in your head.
- If you can’t, try to find the solution with a board and stones.
- If you can’t, look at the solution and replay it on a board, then visualize it in your head (just looking at the initial position).
Repeat several times to train your neural net, and all problems will become obvious. Less obvious is to spot snapbacks in a real game. As a rule of thumb, a group with 3 liberties is often in immediate danger of being captured in a snapback.
Example (not from the book but from one of my games):
It’s Black turn, but if Black plays elsewhere, can White capture the marked group?
In problem 40/41-3 I found it strange that White played a ko instead of attacking the cutting stone. Is there something wrong with this sequence to show how Black can connect in sente?
Also, does the tesuji have a name?
I think your sequence is implicit in the book’s solution. White would like to capture the cutting stone like in your diagram but can’t because of lack of liberties. The only way to gain an additional liberty is to capture the ko but Black can still save his cutting stone like in the solution diagram of the book.
In practice, in a real game White doesn’t want to play like in your diagram because it’s gote for White.
He said this nicely in the first chapter:
If you respect your opponent’s reading ability you’ll want to avoid many of the even-numbered moves in the answer diagrams of this book.
Yes, sente is more valuable as a few more points here. Black has to answer to connect or white can eat his cutting stone. White then can play elsewhere.
So I just finished rereading chapter 3. I’m going to move on and post about chapter 4 in a week or so.
I have started re-reading the book as well, I am in chapter 2, but I’ll probably get to chapter 3-4 tomorrow.
Regarding the squeeze and the snapback, I have not noticed any particular shapes that occur for it, but it is all a matter whether there are sente moves (usually atari), that force the opponent to play connecting moves that ultimately reduce their liberties. Then, at the end, there might or might not be a snapback, but usually the squeeze itself is quite a good result in and of itself.
Since the topic is a “book club” another example from my own book might help you:
In the last board, it might be hard to believe, but all those White stones get squeezed and die. It seems such a wide and safe group, doesn’t it? But too many ataris and tiger’s mouths can be detrimental. I will not bore you with that, I actually spend four pages (156-159) with that example. Feel free to download it and read it on your own pace, but imho it was worth the time and space.
Squeezing, throwing in and going for the snapback are worth the trouble to learn, plus there are immensely fun when they work out.
I suppose snapbacks are just one of the ways things get captured on low liberties.
It doesn’t always have to be a snapback but it can be especially when groups aren’t solidly connected.
Random examples where snapbacks can show up in different Tsumego
If you watch capture fights (semeai in J.) you will often see players sacrificing a stone, or at reverse some solide connection avoiding this tactic. Those sacrifices are played to reduce the total amount of liberties.
When capturing the sacrifice results in a chain with 1 liberty only (which can be captured) this is called snap back.
Players miss them when they are too sure of their connection and not yet very used to sacrifices technics.