Book Club. Tesuji by James Davies, Chapters 1 and 2

[saxmaam]

I’d like to start a discussion of Tesuji by James Davies.

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.

My notes follow.

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Chapter 1. Reading

This chapter shows an exhaustive reading example that involves reading up and down a possible move tree. That looks well beyond my abilities, and I guess the point is that knowing tesuji can help us when the reading is too hard.

I don’t follow the two moves in a row comment in the following quote. He’s not talking about ko, so how does one effectively get two moves in a row somewhere?

“you lose much more by having a lot of stones captured in a sequence that fails than by letting your opponent defend where you could have destroyed him. In the latter case, while your opponent is defending you get two moves in a row elsewhere on the board”

Can someone show an example?

Chapter 2. Capture the Cutting Stones

I’ve encountered many of these ideas before in working problems, but I like having them put together by theme. I’ll have to work through these repeatedly to really get them, I think.

The cross-cut tesuji in particular seems to be over my head. I don’t know how to think about it. I realize that somehow the initial move threatens both the diagonal connection and the 2 point jump on the third line. I see lots of stones with just two liberties in the diagrams. I see a sacrifice stone. I see a double atari. I think that grasping this will definitely improve my game.

I lost track of how many of the final ten problems I got right. It wasn’t an impressive percentage, however.

[Uberdude]

@saxmaam

“you lose much more by having a lot of stones captured in a sequence that fails than by letting your opponent defend where you could have destroyed him. In the latter case, while your opponent is defending you get two moves in a row elsewhere on the board”

Can someone show an example?

He just means you get 2 gote moves in a row, not an ignored sente move.

Black could kill with 1 but didn’t realise and plays elsewhere, white realises and defends with 2, black gets second move elsewhere with 3.

[Groin]

Tesuji has a special place in my heart. Why?
Because i didn’t read it. (I was then like 7k)

Instead I searched it, each problem, one by one.
I can’t say that it is because of that that I reached like 3k because during that time, like a few months, i was very very active, playing in many tournaments IRL.

@saxmaam

That looks well beyond my abilities, and I guess the point is that knowing tesuji can help us when the reading is too hard.

Only the first chapter i didn’t search as it is complicated, an introduction of how to search.
To me the author mosty wanted to push the reader to study, not just read.

All the other dias, I duplicated on a wood board with stones. And found by myself where to play without putting more stones. It seemed that this book was perfectly fitted to what i needed to improve.

[jlt]

I read the book 3 or 4 times. Problems were hard the first time, when I was 12k. Now tesujis in the book feel familiar, which doesn’t mean I never miss them in a game…

[JethOrensin]

This is a book that I plan to study soon (I’ve only read it once), so it is a happy coincidence. By memory I can only say that this is a very good and useful book and I’ll be glad to add feedback later, once I get back at it.

@saxmaam

Can someone show an example?

On your question, if you want a practical example, as luck would have it I have a similar in my book of how I understand this concept, and since this is a book topic here it is. For context in the previous page (127 - feel free to download it and look at the whole thing) it is pointed out that Black aims to play at either 1 or 2 and in this page it is shown how he tries to play at both those points, by making white defend.

The idea here is that there is a threat of losing some stones, but if that loss is not significant compared to the kind of moves that exist elsewhere on the board, then if you spend two moves on capturing those stones, then in reality the opponent won the exchange, since they got to play two free (unanswered) moves elsewhere on the board.

If anyone wants to be pedantic about Davies not meaning exactly that, yes, you are correct. But it is a very similar concept. Another similar way to view this idea is this, that maybe you can kill the opponent, but why bother when squeezing is much more profitable:

I was Black in that game and while I did “manage to survive” (I realised that the stronger opponent was squeezing, so it is not so much that I managed it, but it was the opponent’s plan to let me live with a couple of points) it was White that gained a lot more points than the ones that my living group managed to reduce. He later used all that influence to gain even more and attack all over the place. In that case he didn’t get only two free moves out of that life and death situation, but more like fifteen “free” moves.

[shinuito]

@saxmaam

I don’t follow the two moves in a row comment in the following quote. He’s not talking about ko, so how does one effectively get two moves in a row somewhere?

“you lose much more by having a lot of stones captured in a sequence that fails than by letting your opponent defend where you could have destroyed him. In the latter case, while your opponent is defending you get two moves in a row elsewhere on the board”

Can someone show an example?

The example could be the problem itself

As in you haven’t fully read it out, you play away, your opponent realises they have a cutting issue and so they defend, and then you get a second move elsewhere. (1 and 3 supposing to be interpreted as “away” more like @Uberdude ’s example)

[shinuito]

@Groin

To me the author mosty wanted to push the reader to study, not just read.

I think this is just a perspective on learning. I think some books and authors will suggest that you just read though once, don’t worry if you can’t solve something because seeing the solution will help you improve. Then the next read through you’ll have a better chance to solve the ones you couldn’t before.

Other people suggest that you struggle to solve puzzles, and the struggle can mean people don’t ever even finish the book which is probably worse than just seeing the answers.

But of course it can be rewarding and more memorable when you do find things yourself also.

I think the intermediate is when you see the answer that you couldn’t understand, try to see why it works, and how it might show up elsewhere or what are the key stones that are making it work and so on.

[saxmaam]

@shinuito

@Groin

To me the author mosty wanted to push the reader to study, not just read.

Other people suggest that you struggle to solve puzzles, and the struggle can mean people don’t ever even finish the book which is probably worse than just seeing the answers.

i have made this mistake so much!

[yebellz]

Even if one cannot solve all of the accompanying problems, I think that the examples systematically given in the text can help in providing exposure to new ideas to consider when reading in practice. A general aspect of tesuji is that they are sometimes counter-intuitive (for those lacking some experience with them) and hence the correct moves could be overlooked when one is not familiar with certain patterns. But just reading through this book might help with improving one’s pattern recognition and possibly broaden one’s reading abilities when try to solve tricky situations.

[Groin]

@yebellz

I think that the examples systematically given in the text can help in providing exposure to new ideas to consider when reading in practice

Yep, if you don’t grasp something from the example in each chapter, then maybe you’re just not ready yet for this book.

[saxmaam]

So far this thread has concerned my thoughts about the material and responses to them. i am pleased with all of it, but i don’t want this to be a one-sided conversation.

if you have read these chapters or decide to read them now, please share your thoughts. Did anything surprise you? Do you have questions?

[jlt]

I’m not really reading it, rather taking the opportunity to check how fast I can solve the problems. I’ll however share an observation that I found useful when I studied the book a few years ago: in loose ladders (see the link to Sensei’s Library), the key point is that Black has at least three liberties. This observation may seem trivial but I wasn’t aware of it, and once it was formulated, all variations became clear.

[shinuito]

@saxmaam

The cross-cut tesuji in particular seems to be over my head. I don’t know how to think about it. I realize that somehow the initial move threatens both the diagonal connection and the 2 point jump on the third line. I see lots of stones with just two liberties in the diagrams. I see a sacrifice stone. I see a double atari. I think that grasping this will definitely improve my game.

I kind of see it as one particular aspect of a whole line of variations. In some sense it’s what’s being said in the first chapter that the tesujis help speed up reading

the attachments to kosumis come up a good bit, as forcing moves. If you can force the opponent to go in a certain direction in the centre or to the edge of the board, maybe you can capture if they run into an edge or another wall, or maybe you can get a wall of stones you can use for another purpose.

The cross cut part is kind of branch of this attachment, attach + hane is kind of natural to put pressure on the attachment stone (removing a liberty) and then whether you can get a net positive from the cross cut, like capturing cutting stones, capturing the whole group or causing some other large damage to surrounding groups is kind of the thing making it a tesuji.

I do feel like some of the cross cut problems aren’t exactly straight forward overall, but just that the capturing the cutting stones is a possible variation is kind of what the message is to be taken out of it, I think, given the chapter.

I don’t think a sample variation like

is particularly simple, because then you need to evaluate what also happened on the outside, white captured two stones and they’re probably alive, blacks corner got damaged and they only got a couple of stones in compensation and so on.

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As an aside, from my own perspective I don’t feel like the chapter really gives you the idea as to why some of the moves are what they are.

The net kind of makes sense, the nose into loose ladders or nets and so on kind of makes sense. Particularly when the surrounding groups are reasonably solid and the inside group has low liberties.

The knights move tesuji for me still isn’t very clear as to when you’re supposed to know that it works. Again I guess when the liberties are low or there’s liberty shortages like

where when black tries to break out their liberties are going to start disappearing really fast because of the empty triangle and kosumi.

Even though in the case of this modified shape

the knights move is super strong, it’s just black has a bit more to work with, hane underneath and tigers mouth and other ideas to try make shape, the liberty shortage not being a severe problem.

[jlt]

Yes I agree that it’s not obvious when the knight’s move tesuji works. The only thing to remember is that the knight’s move is played from the weakest stone and… you have to read variations to check whether it does work.

[yebellz]

@jlt

you have to read variations to check whether it does work

I feel like this is true for basically all of the tesuji. Ultimately, each are just ideas to possibly consider, and one still needs to read ahead to check if they actually work.

[Atorrante]

For people who are interested in actually doing the puzzles: I made a puzzle collection with the 264 puzzle that are presented in this book.
Enjoy.

Note on the numbering of the puzzles: format is [page number - puzzle number].

So Puzzle 15-1 is the first puzzle on page 15.

[saxmaam]

@jlt

I’m not really reading it, rather taking the opportunity to check how fast I can solve the problems. I’ll however share an observation that I found useful when I studied the book a few years ago: in loose ladders (see the link to Sensei’s Library), the key point is that Black has at least three liberties. This observation may seem trivial but I wasn’t aware of it, and once it was formulated, all variations became clear.

Yeah, that’s a big insight.

[yebellz]

I’ve opened the book today and found my bookmark on page 86, where I stopped reading over a year ago, on the problems at the end of Chapter 5. I’ll start over from the beginning to review the earlier material and better participate with others that are also working from the beginning. However, it may take me a week or two to work through the first two chapters and share my thoughts.

[saxmaam]

Yeah, I need some more time with this chapter before going to the next as well.

[Feijoa]

Okay, I’m in!

@saxmaam

Did anything surprise you?

I was thrown off a bit by 3 in Ch1 D7 being called the eye-stealing tesuji. Why are we talking about eyes already when the goal is just to separate?

But after reading the conclusion of the chapter I get it! If we don’t play the best sequence that bottom group could still live disconnected.

And separately maybe tesuji are good moves to consider even to achieve something other than their usual purpose?