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© Copyright 2016 by Thomas Redecker

Tsume-Go Strategy 2

Learn to Recognize Vital Points in Go Problems

Thomas Redecker

Buy the full book at gobooks.com

Have you ever complained about Go problems that are much too difficult for you to solve? And then lost courage?

Inoue Dōsetsu Inseki’s advice — written down over 300 years ago — is to study shape. This book helps you do that and overcome your current weakness in the beautiful field of tsume-go.

Study over 400 problems – based on 44 side patterns – that are analysed in great details. Absorb numerous hints that direct your gaze to previously unrecognized vital shape points.

This book tries a novel approach in offering an important intermediate step between the main problem diagrams and the respective solutions. Alternative approaches as well as failures are presented as separate problems to be solved individually.

This volume is a successor of “Tsume-Go Strategy” (Volume 1), but it can be studied independently.

Copyright Page

First edition.

© 2016, Thomas Redecker, Berlin. All rights reserved.

This book or any portion thereof may not be reproduced or used in any manner whatsoever without the express written permission of the publisher except for the use of brief quotations in a book review or scholarly journal.

Email: igohatsuyoron120@gmail.com

Introduction

“The problems are too difficult!”

… reads a typical complaint which occasionally accompanied the solution attempts of the participants in the problem corner of the bimonthly German Go-Journal.

For most of the problems in question these comments were quite astonishing for me. This was true especially for problems in which it seemed to me that the correct sequence of moves was clearly guided by “typical” elements of the problem’s structure, and shape.

Over a long period of time I thought about a suitable kind of presentation that might help some problem solver to sharpen their view for these typical shape elements. Lately, I was heavily motivated by what Inoue Dōsetsu Inseki (who published the most difficult problem ever created – Igo Hatsuyōron #120) wrote in his afterword to the original edition of his classic book. He explicitly stressed the importance of studying “shape”, and also mentioned that this study would become the more important the stronger you are.

In this book, you will find a very detailed in-depth analysis of 44 (easier) side patterns from another classic problem selection, the Gengen Gokyō, resulting in over 400 individual problems. An evaluation of the difficulty of Gengen Gokyō’s problems is not easy; you will find quite different estimates in the literature. It is often said that these problems might be suitable for players who are at least in the upper single-digit Kyū range.

However, I am firmly convinced that even double-digit Kyū players will gain a lot for their games by studying these problems from Gengen Gokyō, especially the easier ones. A large number of the side patterns that are given in this book can also be found in any standard dictionary of “Life & Death”, so these must be very important for weaker players too.

“Do not look at the solution!”

… regularly reads the most important advice given to those who want to solve Go problems. In real games you are on your own as a Go player and there is no one standing beside you to help with words and deeds.

If you have not found the solution within a reasonable period of time, let’s say about three to five minutes, it is best to switch over to the next problem. Perhaps you do not try so fiercely with the second or third attempt and the correct sequence suddenly falls like scales from your eyes. Then you can enjoy the fantastic feeling to have found the solution on your own.

In Western countries you will not find any problem book without solutions. As a rule there is no teacher available who could answer the pupil’s question “Correct or not correct?” However, it needs a great amount of self-control not to turn over to the page with the solution diagrams too early.

Usually a very important condition is kept back in the advice given in the headline. This additional part of the advice reads “… before you are very sure that you have totally solved it.” This implies that only getting the first move of the solution right, or the main path of the solution sequence, is by far not enough. In your own games – did you ever experience that your opponent did not answer your moves as “demanded” by the books, and caught you by surprise?

Therefore this book tries to follow a middle course. Every problem points to solution hints and not directly to the solution. These hints specify crucial points and try to explain important structures, and shape points, of the problem. If you tried to solve the problem beforehand, and still are not completely sure about your own solution, in most cases you should be able to realize whether your solution is likely to be correct or not by reading the hints carefully.

Subsequently, you will not so often need the solution pages but only in a few remaining cases, perhaps especially with difficult problems. You will also find the view of your opponent or sequences which do not work successfully. Most of these sub-variations are presented as separate problems to make you find their refutations on your own.

And be seriously warned: There is nothing available like an “easy-to-follow cooking recipe” that tells you to do this first, and to do that second. This book can do nothing more than give you numerous hints; it is you alone who will have to find your own individual path for solving Go problems successfully.

The more difficult a problem is the more the solution is kept hidden below the surface. This made the composition of clues for the problems in this book (especially for the later ones) a little bit time consuming. Please take into account that I am a strong Kyū player only when judging the accuracy of the presentation. Several sub-variations cannot be found in other books, and have been developed on my own. Therefore, if you find anything better, or have a question, or a suggestion, please do not hesitate to report via the following email address:
igohatsuyoron120@gmail.com
This book contains more than 6,000 diagrams, so please be forgiving if you find a fault in one of them.

It is my hope that reading this book first of all is fun, and that it also helps to eliminate some of the blind spots which have blocked your way to solving Go problems so far.

Berlin, August 2016
Thomas Redecker

Contents

The chapters in gray are included only in the full book.

Problem 001

Problem 002

Problem 003

Problem 004

Problem 005

Problem 006

Problem 007

Problem 008

Problem 009

Problem 010

Problem 011

Problem 012

Problem 013

Problem 014

Problem 015

Problem 016

Problem 017

Problem 018

Problem 019

Problem 020

Problem 021

Problem 022

Problem 023

Problem 024

Problem 025

Problem 026

Problem 027

Problem 028

Problem 029

Problem 030

Problem 031

Problem 032

Problem 033

Problem 034

Problem 035

Problem 036

Problem 037

Problem 038

Problem 039

Problem 040

Problem 041

Problem 042

Problem 043

Problem 044

Excursus

This collection of “Excursus” gives more detailed explanations on several shape issues.

You might find these additional texts useful, but their study is not mandatory for understanding the hints, or the course of the solutions. Therefore, if the topics covered are well known to you, you might skip these further explanations.

All the “Excursus” are collected at the end of the book, so it will be possible to read these on their own.

Table of contents

Excursus – Real eyes vs. false eyes

Excursus – Cutting points reduce your options for connecting out

Excursus – All stones are shown that might affect the solution

Excursus – Ko fights (I)

Excursus – Capturing a four-stone pyramid shape on the edge

Excursus – Capturing two stones on the edge

Excursus – Capturing three stones on the edge

Excursus – Dead eye shapes

Excursus – Adding a second stone for sacrifice

Excursus – Excursus – “Snakes”

Excursus – Linear shapes vs. bulky shapes

Excursus – The centre of three stones

Excursus – Troubles with descending towards the edge

Excursus – Cutting a keima (knight’s move)

Excursus – Strike at the waist of a keima

Excursus – Under the stones

Excursus – Eight live, six die

Excursus – Excursus – Six live, four die

Excursus – Capturing five stones in a pyramid shape on the edge

Excursus – The 1–2–3 principle

Excursus – Mannen ko (ten thousand year ko)

Excursus – Ko fights (II)

Lessons learned

The conclusion of the book provides a collection of core messages extracted from all the “Lessons learned” that can be found in this book.

Please be well aware that these hints are taken only from failure variations. So it is still your task to find your own way of identifying the correct lines of tsume-go problems.

Table of contents

1–2–3 principle

Atari

Attack

Capture

Connecting

Cutting points

Dead eye shape

Defence

Eye space

False eyes

Holes

Inside

Knight’s move

Ko

Liberties

Moves

Outside

Sacrifice

Semeai

Snakes

Two areas

Zigzag line

Legend: Important shape points and further points of interest

This section introduces the symbols, and labels that are used in this book to highlight various important shape points.

"●"

circle

The potential eye space of a group (here a white one) is marked with "●".
Usually, this space is understood as the maximum that could be achieved (playing own moves for its fortification only).

“e”

eyepoint

Sure eye points are marked with “e”.

“△” / “” / “”

deadeyeshape

Dead eye shapes are marked with “△”. These might be partially occupied (“” / “”).

outsidestrong

Strong positions on the outside (preventing any escape), are marked with “” / “”.

outsidedescent

Important descents that have been played on the outside, and which look deep into the opponent’s position, are marked with “” / “”.

“□”

centralpoint_deadeyeshape

The central point of a dead eye shape is marked with “□”.

“●”

blackliberties

Liberties of black groups are marked with a black dot (●).

“○”

whiteliberties

Liberties of white groups are marked with a white dot (○).

“1” / “2” / “3” / “4” / “5”

libertycount

The liberty count of single stones, and entire groups of stones, is displayed by using the respective number on all involved stones.

Please be aware that – solely in the “Hints” – we use “1” for marking a single stone that has only one liberty left. Do not mismatch these stones with “moves”.

“✕” / “” / “”

falseeye

False eyes are marked with “✕”, the respective opponent stones engaged are marked with “” / “”.

falseeyeline

Lines of potential false eyes are marked with “✕” / “” / “”.

diagonalconnection

Stones, and groups (at their ends) that are not yet securely connected are marked with “” / “”.
These stones / groups may be diagonally adjacent to each other, or have a hole in-between.

zigzagline

A potential zigzag line of stones that should be connected out is marked with “✕” / “” / “”.

zigzaglinear

Please note that we also use this term “zigzag line” if the line of stones that should be connected out (, ✕) is positioned only on the first line.
To be honest, we simply did not find a better one.

stonecapture

Stones that cannot escape capture, or stones that could become captured easily, are marked with “” / “”.

“!!”

hole

The empty space (= hole) between a group, and the edge of the board, is marked with “!!”.

Gaps in the middle of an encirclement are also marked with “!!”.

“◇”

jump

Points on the edge of the board that will serve as potential candidates for a jump from a friendly position ( here), are marked with “◇”.

“ko”

kocapture

The empty point that is left after capturing a single opponent stone in a ko shape (with Black 1 here), is marked with “ko”.

“n”

neutralpoint

Neutral points in a seki are marked with “n”.

“?”

uncertainarea

An area where it might be uncertain whether an eye can be developed there is marked with “?”.

Variation trees

Some readers of the first volume reported that they felt a bit lost in the complexity of some problems with many variations, not really knowing where they were in the context of the entire problem.

For this reason, I decided to add variation trees besides the problems that are reduced to the most necessary information. The presentation style chosen (due to some restrictions of the SmartGo Books format) may be perceived as not ideal, but I am sure that these additional compilations are better than nothing.

Please feel free to utilise these compilations as an aid for your navigation through a dark, deep and twisty forest of leaves.

We use a very “condensed” version of the variation tree, showing its branching points only. The following example shows the variation tree of problem 001, including additional explanations of the variation levels.

1 start main line

  `-> 1   var. for Black 1 (I)

 :        `-> 3     sub-var. for Black 3

  `-> 1   var. for Black 1 (II)

 :        `-> 3     sub-var. for Black 3

 :       :        `-> 4       sub-sub-var for White 4

  `-> 1   var. for Black 1 (III)

 :        `-> 2     sub-var. for White 2

 :       :        `-> 3       sub-sub-var. for Black 3

 :        `-> 3   sub-var. for Black 3

2 continuation main line

  `-> 2   var. for White 2

4 continuation main line

  `-> 4   var. for White 4

5 continuation main line

  `-> 5   var. for Black 5

Please note that we display “branching moves” of a superordinate level only for the main line.

In the book, there will be no explanations of the variation levels.

1
    > 1
            > 3
    > 1
            > 3
                    > 4
○ ● ○ ● ○ ● ○ ● ○
    > 1
● ○ ● ○ ● ○ ● ○ ●
            > 2
                    > 3
            > 3
2
    > 2
4
    > 4
5
    > 5

Legend:

Text in bold font refers to a problem (mainly failure diagrams).

Text in normal font refers to a variation.

○ ● ○ ● ○ ● ○ ● ○
Text in black font between the two lines of small “stones” (here: the third sub-variation for Black 1) refers to the current problem.
● ○ ● ○ ● ○ ● ○ ●

All other lines can be tapped for direct access to the respective problem / variation.

Glossary

Atari

atari

The state of a stone or a group () which has only one liberty (○; and could be captured by the next move). Very often used for the move itself (here: Black 1) which takes the penultimate liberty.

Bamboo joint

bamboo joint

The shape of the four black stones after Black played 1. It is normally impossible to cut through this strong connection.

Descent

descent

A move like Black 1, which descends towards the edge of the board.

Double-ko

doubleko

Two ko, happening simultaneously in the same fight, and serving the same purpose. If one player captures the first ko (here with Black A / Black 1), the other player captures the second ko (with White C / White 4). Can become a large supply of ko threats (here for Black) if there is another ko on the board.

Gote

Losing the initiative. A move which need not be answered.

Guzumi

guzumi

Good bad shape. A shape (usually an empty triangle), which looks bad, but is good, and effective, in the local context.

Hane

hane

A diagonal move played from one’s own stone, in contact with and around an opponent stone. Often facing the edge of the board.

Keima (Knight’s move)

keima

A relationship of two stones that is similar to the movement of a knight’s piece in chess. Black 1 is a keima = (small) knight’s move from .
If the jump goes one line further, like White 2 from , it is called “ōgeima” (= large knight’s move).

Kikashi

kikashi

Forcing move. A sente move, which often has some additional effect that might be used later. Often played outside the main flow of play.

Ko

ko-rule

Shape in which the rules prohibit the immediate capture of a single stone (White 2) that has just captured a single stone at the prohibited point (ko).

Me ari me nashi (One eye vs. no eye)

me ari me nashi

Capturing race wherein one side () has an eye (e), the other () does not.

Miai

miai

Two options with the same value, or purpose. If one player takes one of them, the other one is left for the opponent (who is often forced to play there).

Seki

seki

Mutual life, shared life. A configuration where groups of both colours share liberties, and are not independently alive. Neither side may capture any of their opponent stones without losing more points than they gain.

Semeai

“Capturing race”. Fight for life and death, usually involving only two groups.

Sente

Initiative. A move which is answered.

Shortage of liberties

shortage of liberties

For example, Black cannot play at A to secure two eyes for his group without putting his own stones () in atari.

Snapback

snapback

One side sacrifices a single stone (here White 1, which is captured by Black 2) in order to recapture a larger opponent’s group (here with White 3).

Tesuji

A skilful move that is the best play in a local position.

Throw-in

throw-in

An aid to killing or capturing using a sacrifice stone, which results in a false eye shape (, ✕) and which is often used to prevent the opponent from connecting at that point, or to reduce eye space.

Tsume-Go

The field of “Life & Death” problems.

Problems

Problem 001

Black to kill.

< Go to the solution >

< Go to the next problem >

All the problem diagrams in this book are interactive, but probably not as you expected.

I ask for your kind understanding that it was not possible to include entire solution sequences. There are so many sub-variations available that it would not really help to have only the main line included; but realising the entire variation tree is impractical.

Therefore, you will find “level 1” of the variation tree only; this is the next move, here “1”. The feedback of the program is as follows:

- When tapping on a “correct” solution point, the respective stone will be displayed.
– When tapping on a “failure” point that is further explained in the book, the respective stone will be played, but with a red “X” on it.
– When tapping on any other board point, only a red “X” will be shown.

This is useful for two reasons:

– You will be able to check your main ideas to some extent before flipping the pages.
– You will be shown which failure moves will be explained and their refutations discussed.

Please kindly note that correct starting points that result from a change in the order of moves of the solution sequence might not be highlighted as “correct” in the respective problem diagram.

Next column: Variation tree

○ ● ○ ● ○ ● ○ ● ○
1
● ○ ● ○ ● ○ ● ○ ●
    > 1
            > 3
    > 1
            > 3
                    > 4
    > 1
            > 2
                    > 3
            > 3
2
    > 2
4
    > 4
5
    > 5

Next page: Hints

Hints 001

White’s potential eye space (●) is already divided into two parts.

At the top, there is one sure eye (e) for White.

The marked area on the bottom (?) is still unsettled, so Black will have to stop White from getting her second eye there.

Parts of White’s formation are not yet solidly connected (), leaving cutting points for Black to exploit.

White’s single stones at the left have only two liberties, and so are very vulnerable to an attack.

However, this book is about tsume-go, and so you should be on your guard here.

It is always advisable to think twice before giving atari to a single stone (or a group of stones) – especially in the very beginning of the solution sequence – as this move might be sente.

It is also very advisable to think twice before cutting into the opponent’s formation – especially in the very beginning of the solution sequence– just for the sake of capturing some stone(s) that look like as if they could become captured quite easily,

Very often, these types of “easy prey” are only on the board to bedazzle your mind!

White’s large group at the right has four liberties, and so will not be the primary aim of Black’s forthcoming attack.

In the left centre of the bottom area, there is a line of false eyes visible (, ✕).

< Excursus – Real eyes vs. false eyes >

Please note that Black also needs a permanent stone at its other end on the bottom to bring this line to life.

At the utmost left, there is already a false eye for White (, ✕).

At the left, White’s -stones deny Black easy access from that side.

At the right, there is a hole (!!) in White’s encirclement, giving Black access to the bottom area inside White’s formation.

At the right, Black has a strong outside position () that is looking forward to friendly stones on at least one of the ◇-points.

However, Black must be very well aware that connecting stones out that are arranged on a zigzag line (✕, ) might suffer from a shortage of liberties.

< Excursus – Cutting points reduce your options for connecting out >

< Return to the problem >

Next page: Solution

Solution 001

The placement of Black 1 hits the vital point of the problem. This move threatens either to connect out to the right, by playing at A, or to cut / give atari at the left, by playing at B.

Black will succeed neither by cutting at the left, nor by playing hane at the right, nor by jumping one point farther to the left.

Tapping on hyperlinks like those above (i.e. the text in blue) will take you to another sub-variation of the current variation tree. This will include either another problem (for a mistaken choice) or a variation (for an alternative option).

At the end of these sub-variations you will find a hyperlink that brings you back again. Hopefully this will ease your attempts to analyze the various options that are included in the problem.

White descends to 2, blocking Black’s escape route to the right.

White might try to play at the left, with a move at A, instead, but this option will not work either.

Black uses his second option and cuts at 3.

Black’s last move is also an atari, so White connects at 4.

White might try to give atari at A instead, but this option will not work either.

Black 5 descends on the outside, simultaneously occupying an important liberty of White’s right-hand group. Now, neither side can play at A or at B.

Black, however, can attack White’s left-hand group from the outside and capture it, eventually resolving the partial seki mentioned above. White’s right-hand group has only one eye, and so is dead.

This descent is the usual move shown in the books. In a real game, it might be advisable, because it solidly closes the bottom area.

< Excursus – All stones are shown that might affect the solution >

Black might consider giving atari at C instead.

< Return to the hints >

< Go to the next problem >

Next column: Variation

Variation for Black 5

Black 5 gives atari to White’s three stones.

White’s counter-atari at 6 is fruitless.

Black simply captures at 7, and there is nothing left that White could do at the left.

At the very end of every single (sub-) variation you will find a diagram like this one above, showing the status of the final position.

< Return to the hints >

< Return to previous choice >

You will find hyperlinks “Return to previous choice” at the end of every sub-variation. Tapping on these will take you (probably back) to the superordinate branching point of the current variation tree. Hopefully this feature will ease browsing through the various options that are included in the problem.

Next column: Variation

Variation for White 4

White 4 gives counter-atari at two single black stones, but this will not lead to success.

Black 5 captures White’s single stone at the left, saving his just-played stone on the second line.

White desperately captures a black stone with 6, but there will be no ko.

Black 7 simply connects solidly, and White is left with a false eye on the bottom.

< Return to the hints >

< Return to previous choice >

Next column: Variation

Variation for White 2

The diagonal move of White 2 hinders Black from cutting at the left.

Black, however, uses his second option and connects his pivotal stone out with 3.

White desperately gives atari with 4.

Black must answer with the solid connection of 5, saving his two stones. On the lower edge, White has only false eyes, and so is dead.

< Return to the hints >

< Return to previous choice >

Next page: Failure

001 Problem (failure I)

Black just cut at the left.

Maybe you wonder about the fact that White’s last (mistaken) move is not highlighted in the problem diagram, but described only verbally in the text above. You might remember that this was also the case in the comment of the solution’s main line that linked to this sub-variation here.

The reasoning for doing so is quite simple: I do not want you to memorize, and to learn, false moves.

White to live (by means of ko).

Probably you are taken by surprise to find the explicit hint in parenthesis above, making it evident that the correct solution to the problem will result in a ko fight.

This is quite unusual for books on Go problems, and it is also said to be somewhat counterproductive to the aims that should be reached by studying such a book. Of course in real games there is no one standing nearby telling you to be aware of “ko” just now.

However, “ko” is one of my very blind spots, and I would like to assume that it is not me alone who suffers from this kind of “debility of sight”. For this reason, the treatment of ko fights in this book will be much more detailed than usual.

< Go to the next failure >

Next column: Variation tree

1
○ ● ○ ● ○ ● ○ ● ○
    > 1
● ○ ● ○ ● ○ ● ○ ●
            > 3
    > 1
            > 3
                    > 4
    > 1
            > 2
                    > 3
            > 3
2
    > 2
4
    > 4
5
    > 5

Next page: Solution

001 Solution (failure I)

Think twice before giving atari to a single opponent stone! Your opponent might not connect, taking you by surprise.

White 2 gives atari from below, using the special arrangement of her -stones at the left.

Black captures with 3, starting a ko fight for the life of White’s group.

Giving atari in the corner instead will also result in a ko fight, but Black should refrain from doing so.

Gaining a ko is a success for White here, because Black could have done better and killed her group unconditionally.

From White’s point of view, this ko is a bit like an approach-move ko. White has to look for the first valid ko threat.

If Black wins the ko fight.

● ○ ● ○ ● ○ ● ○ ● ○ ●

White 4 is a valid ko threat, answered by Black 5.

Please note that – when explaining an entire course of a ko fight – ko threats which are placed outside the problem area (i.e. “are played elsewhere”; here White 4) are displayed in an empty area at a border of the diagrams.

Please also note that answers (here Black 5) to valid ko threats are also shown in that border area of the diagrams, at a point that is adjacent to the respective ko threat.

None of these moves is assumed to change the environmental conditions on the “outside” of the original problem.

White recaptures the ko with 6.

< Excursus – Ko fights (I) >

Instead of looking for a external ko threat of his own in the rest of the board, Black plays the atari of 7 here as a local / an internal ko-threat.

White is unable to connect the ko at A, due to Black B, and so captures Black’s remaining stone with 8.

Black 9 recaptures the ko.

White 10 is the second valid ko threat that White will have to find.

White 12 recaptures the ko again.

In principle, playing White 10 at A instead will not make a big difference. Black simply captures at B, and the ko will be fought around the -point now.

However, if White had supporting stones on the lower edge, the descent to A might provide her with several internal ko threats at the bottom right, threatening to connect her group successfully to the outside.

White ignores Black’s ko threat of 13 to connect the ko with 14.

Please note that White needed two more valid ko threats than Black to win the ko fight here, instead of only one.

If White wins the ko fight.

< Return to the hints >

< Return to previous choice >

Next column: Lessons learned

Lessons learned

Think twice before giving atari to a single opponent stone!

Be aware that your opponent will think twice before connecting a single stone that is in atari.

Consider carefully whether your opponent might be able to establish a ko shape (, △), forcing you to start an uncalled-for ko fight.

Establishing a valid line of false eyes (, ✕) requires your stones occupying both end points of this line, not occupying its central point.

< Return to the problem >

Next page: Failure

001 Problem (failure II)

Black just played atari in the corner.

White to live (by means of ko).

< Go to the next failure >

Next column: Variation tree

1
    > 1
○ ● ○ ● ○ ● ○ ● ○
            > 3
● ○ ● ○ ● ○ ● ○ ●
    > 1
            > 3
                    > 4
    > 1
            > 2
                    > 3
            > 3
2
    > 2
4
    > 4
5
    > 5

Next page: Solution

001 Solution (failure II)

White 4 captures Black’s single stone inside her formation.

Black has to capture at 5.

This ko fight is favourable for White, but nevertheless, she has to look for the first valid ko threat.

White 6 is a valid ko threat that is answered by Black 7.

White 8 recaptures the ko.

White ignores Black’s ko threat of 9 in order to connect at 10, ending the ko fight in her favour.

If White wins the ko fight.

○ ● ○ ● ○ ● ○ ● ○ ● ○

Black ignores White’s first ko threat and connects the ko at 7.

But this connection will not terminate the ko fight.

White’s descent to 8 threatens to continue at 9, securing her second eye.

Black 9 captures, continuing the ko fight, in which the ko shape simply changed place.

This is a direct ko now. White has to find the first valid ko threat.

Black ignores White’s ko threat of 10 in order to connect at 11, ending the ko fight.

Black had to ignore two white ko threats to win the ko fight, not only one.

If Black wins the ko fight.

< Return to the hints >

< Return to previous choice >

Next column: Lessons learned

Lessons learned

Do not play a forcing move from the outside () instead of capturing a ko.

You might lose internal ko threats unnecessarily.

Do not let your opponent create a series of nested ko shapes ().

You will have to ignore two ko threats to win the ko fight, instead of only one.

< Return to the problem >

Next page: Failure

001 Problem (failure III)

Black just played hane at the right.

White to live (by means of ko).

< Go to the next failure >

Next column: Variation tree

1
    > 1
            > 3
○ ● ○ ● ○ ● ○ ● ○
    > 1
● ○ ● ○ ● ○ ● ○ ●
            > 3
                    > 4
    > 1
            > 2
                    > 3
            > 3
2
    > 2
4
    > 4
5
    > 5

Next page: Solution

001 Solution (failure III)

White blocks Black’s further approach with the atari of 2, aiming at a potential eye space that is as large as possible.

Please note that White occupied the vital point of the problem that Black should have taken in the very beginning.

Black cuts at 3, stopping White from getting an eye on the bottom quite easily.

Black must not play atari to the first line instead.

White 4 is a counter-atari. Black has to capture with 5, starting a ko fight again.

White has to look for the first valid ko threat.

This ko fight is advantageous for Black, because White will need two more valid ko threats than Black to win the fight.

If Black wins the ko fight.

● ○ ● ○ ● ○ ● ○ ● ○ ●

White plays a valid ko threat with 6 that is answered by Black 7.

This enables her to recapture the ko with 8.

The atari of Black 9 is an internal ko threat.

Due to Black , White is unable to connect the ko with a move at A, and so has to capture at 10 instead.

Black 11 recaptures the ko.

White plays another valid ko threat with 12.

Please note that White – in a real game; with supporting stones on the lower edge – might profit from capturing at A (as an internal ko threat), if this move contains a threat to connect to the outside successfully.

White connects the ko with 16, ignoring Black’s ko threat of 15.

Again, White needed two more valid ko threats than Black to win the ko fight.

If White wins the ko fight.

< Return to the hints >

< Return to previous choice >

Next column: Lessons learned

Lessons learned

Before reducing from the outside, consider carefully whether your opponent’s remaining potential eye space might be sufficient for building an eye.

The central point (□) of a dead eye shape (△, □) inside your opponent’s formation often guides you to an important shape point.

But do not assume that the work will be always done with only occupying this point.

Your opponent will think twice before connecting a single stone that is put in atari.

Consider carefully whether your opponent might be able to establish a ko shape (, △), forcing you to start an uncalled-for ko fight.

Your opponent’s initial reply (△) might be the vital point that you should have taken.

< Return to the problem >

Next page: Failure

001 Problem (failure IV)

Black just played atari to the first line.

White to live.

< Go to the next failure >

Next column: Variation tree

1
    > 1
            > 3
    > 1
○ ● ○ ● ○ ● ○ ● ○
            > 3
● ○ ● ○ ● ○ ● ○ ●
                    > 4
    > 1
            > 2
                    > 3
            > 3
2
    > 2
4
    > 4
5
    > 5

Next page: Solution

001 Solution (failure IV)

White 4 simply captures at the right.

She might give atari at A instead.

Black 5 desperately cuts at the left, but White 6 immobilises his two stones successfully.

Playing 5 at 8 is useless as well. White simply captures Black’s two stones with a move at 5, securing her second eye on the bottom, at the point of 6.

Black gives atari with 7, forcing White to capture his two stones with 8. Eventually, White has got a living shape.

Black is unable to capture with 7 at 8, due to the snap-back of White A.

< Return to the hints >

< Return to previous choice >

Next column: Variation

Variation for White 4

White 4 gives atari at the left.

Capturing with 5 will not benefit Black.

White gives atari with 6, and Black would have to invest two moves in a row (A and B) to save his stones. White will live by capturing Black’s two stones that are in atari.

Connecting at 7 reduces the shape on the bottom to only one eye, but this move is fruitless here. White simply captures four black stones with 8.

The placement of Black 9 does not work here, due to White’s strong position at the left (and her second eye above). White connects at 10 and is alive.

< Excursus – Capturing a four-stone pyramid shape on the edge >

< Return to the hints >

< Return to previous choice >

Next column: Lessons learned

Lessons learned

Think twice before giving atari to a single opponent stone!

Be aware that your opponent will think twice before connecting a single stone that is put in atari.

Remember that connecting stones out that are arranged on a zigzag line (, ✕) might suffer from a shortage of liberties.

Capturing a four-stone pyramid shape (, , ✕) on the bottom is equivalent to an eye (in gote).

Your opponent will defend their important cutting points in order to consolidate the borders of their formation.

< Return to the problem >

Next page: Failure

001 Problem (failure V)

Black just played a placement on the first line.

White to live.

< Go to the next problem >

Next column: Variation tree

1
    > 1
            > 3
    > 1
            > 3
                    > 4
○ ● ○ ● ○ ● ○ ● ○
    > 1
● ○ ● ○ ● ○ ● ○ ●
            > 2
                    > 3
            > 3
2
    > 2
4
    > 4
5
    > 5

Next page: Solution

001 Solution (failure V)

White 2 occupies the vital point of the problem, securing life for her group. Black’s initially played stone lost a decisive liberty by this move.

Please note this is the point that Black should have taken beforehand.

Alternatively, White might consider immediately connecting at A instead.

The cut of Black 3 is a desperate attempt, but will be frustrated by White 4.

Black might consider playing 3 at A, but this will also fail to kill White.

It is fruitless for Black to capture with 5.

In a real game, Black would recognize his mistake with 3, and continue on the outside, with 5 at A (White will live by capturing two black stones with a move at 5).

White 6 captures Black’s three stones in a snap-back.

Black throws in with 7, but White captures with 8 and secures her second eye above.

In a real game, Black will play 7 at A, forcing White to connect at 7.

Black 9 blocks the corner. White connects with 10 and lives with two eyes.

< Return to the hints >

< Return to previous choice >

Next column: Variation

Variation for Black 3

Black has the option to give atari from the left, with the move at 3.

White cannot connect at A, due to her shortage of liberties. However, the connection at 4 does the job.

Capturing with Black 5 does not have any effect on White’s second eye at A.

White recaptures with 6 here, for demonstrative purposes only.

< Excursus – Capturing two stones on the edge >

Black 7 captures White’s single stone, simultaneously making the eye on the first line false. But White has already two eyes elsewhere, and so is alive.

< Return to the hints >

< Return to previous choice >

Next column: Variation

Variation for White 2

White 2 solidly connects at the left, in principle immobilising Black’s just-played stone inside her formation.

Black 3 extends to the right, occupying the vital point of the problem, but this move comes too late now.

Black might consider playing at 4 instead.

White’s descent to 4 blocks Black’s escape route to the right.

Cutting at the left, by playing at 5, does not benefit Black.

White 6 captures three black stones for an eye.

Black throws in at 7, but White captures at 8, occupying the miai point.

White has got two eyes, and so is alive.

< Excursus – Capturing three stones on the edge >

< Return to the hints >

< Return to previous choice >

Next column: Variation

Variation for Black 3 (White 2)

Black’s hane at 3 also tries to connect his stone out to the right.

However, White throws in at 4, aiming at creating a shortage of liberties on Black’s side.

Black captures with 5.

In a real game, Black will connect at A at the right, forcing White to capture at B at the left, avoiding an uncalled-for ko fight for the life of her group.

White connects at 6, also giving atari.

Black is unable to connect his two stones at A, due to White B.

Black 7 connects at the outside, forcing White to live by capturing two black stones.

< Return to the hints >

< Return to previous choice >

Next column: Lessons learned

Lessons learned

Before jumping deeply into your opponent’s formation, aiming at destroying a potential eye, consider carefully your options for connecting out.

Only one hole (!!) in your opponent’s encirclement might not be sufficient for success. Your opponent might have a quite simple option for defence up their sleeves.

Do not be taken by surprise if your opponent simply connects an important cutting point in their formation.

Consider the liberty count of your own stones carefully.

Capturing the central stone of a line of false eyes () alone might result in an uncalled-for snap-back.

Remember that connecting stones out that are arranged on a zigzag line (, ✕) might suffer from a shortage of liberties.

Your opponent’s initial reply (△) might be the vital point that you should have taken.

However, there is no guarantee that each such point (△) will be really a correct starting point for the solution sequence.

That alternative option still might be better than your current move, but nevertheless, not as good as the correct solution.

Remember that it is always necessary to think before making a choice between two seemingly equal valued options.

< Return to the problem >

Problems 2 to 44 are included only in the full book.

Excursus

This collection of “Excursus” gives more detailed explanations on several shape issues.

You might find these additional texts useful, but their study is not mandatory for understanding the hints, or the course of the solutions. Therefore, if the topics covered are well known to you, you might skip these further explanations.

Table of contents

Excursus – Real eyes vs. false eyes

Excursus – Cutting points reduce your options for connecting out

Excursus – All stones are shown that might affect the solution

Excursus – Ko fights (I)

Excursus – Capturing a four-stone pyramid shape on the edge

Excursus – Capturing two stones on the edge

Excursus – Capturing three stones on the edge

Excursus – Dead eye shapes

Excursus – Adding a second stone for sacrifice

Excursus – Excursus – “Snakes”

Excursus – Linear shapes vs. bulky shapes

Excursus – The centre of three stones

Excursus – Troubles with descending towards the edge

Excursus – Cutting a keima (knight’s move)

Excursus – Strike at the waist of a keima

Excursus – Under the stones

Excursus – Eight live, six die

Excursus – Excursus – Six live, four die

Excursus – Capturing five stones in a pyramid shape on the edge

Excursus – The 1–2–3 principle

Excursus – Mannen ko (ten thousand year ko)

Excursus – Ko fights (II)

Excursus – Real eyes vs. false eyes

You have created a “real” single eye point e if, and only if, you are the “owner” of at least three of its four diagonally adjacent board points (✕).

This means that either you have occupied these points with your own stones (), or your opponent is hindered effectively from occupying these (◇; e.g. because you could easily capture a corresponding opponent stone).

○ ● ○ ● ○ ● ○ ● ○ ● ○

However, if your opponent succeeded in taking at least two of the diagonally adjacent board points (), your potential eye point has vanished, and has been turned into a “false” eye (✕).

< Return to the hints >

< Return to the table of contents >

Lessons learned

This chapter is a collection of core messages taken from the “Lessons learned” that can be found in this book.

Please be well aware that these hints are taken only from failure variations. So it is still your task to find your own way of identifying the correct lines of tsume-go problems.

Table of contents

1–2–3 principle

Atari

Attack

Capture

Connecting

Cutting points

Dead eye shape

Defence

Eye space

False eyes

Holes

Inside

Knight’s move

Ko

Liberties

Moves

Outside

Sacrifice

Semeai

Snakes

Two areas

Zigzag line

1–2–3 principle

Think twice before initiating a forcing exchange (from the outside) that might strengthen your opponent’s formation.

Consider carefully whether you might be able to do without (or even later), playing (one of the options for) your second move first.

However, there is no guarantee that each such point will be really a correct starting point for the solution sequence.
That alternative option still might be better than your current move, but nevertheless, not as good as the correct solution.

Remember that it is always necessary to think before making a choice between two seemingly equal valued options.

< Return to the table of contents >

References

You will find many more references to printed versions of “Gengen Gokyō” at Sensei’s Library.

Hashimoto Utarō 9p:

“Gengen Gokyō”
Sankaidō, 1979, ISBN 4–381–00570–8

Cho Hye-yeon 9p:

“Baduk Classic: The Profound and Mysterious”
CJ E&M, 2014, ISBN 979–11–85635–08–8

John Fairbairn:

“The Gateway to All Marvels”
SmartGo Books, 2012

My books

The most difficult problem ever: Igo Hatsuyōron 120

The most difficult of all Go problems, created by Inoue Dosetsu Inseki (1646 – 1719), has still not been solved by professional Go players. The long-standing collaboration of three amateurs from Germany and the United Kingdom has now found the answer!

This book celebrates the problem-collection’s 300th anniversary and is the most comprehensive collection of information about this stunning problem. The book discusses what the authors believe to be the solution to the problem, including an in-depth treatment of the failed lines. All move sequences are explained in great detail. The same is true for the additional work on theoretical issues that are fundamental to the problem (e.g. hanezeki, approach-move liberties, and ko).

English, German
SmartGo Books, 2013
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Igo Hatsuyōron 120 – An Elephant in Slices

The most difficult of all Go problems, created by Inoue Dosetsu Inseki (1646 – 1719), has still not been solved by professional Go players.

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This book presents this difficult problem in 120 slices. Each aspect of Igo Hatsuyōron 120 is explained using relatively simple individual problems, so you can understand the entire puzzle.

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SmartGo Books, 2015
$6.99; 484 pages; 121 problems

Igo Hatsuyōron 120 – Below the surface of most difficult problem ever

Igo Hatsuyōron is the most difficult of the classical books on tsume go.

This problem collection was compiled in 1713 by Dosetsu Inseki, the third head of the Inoue Go School, and was designed for the training of the highest calibre students at the school. It was kept secret from all but a few of them, who studied the book under the direct supervision of the Inoue.

183 problems (of estimated more than 1,500) have survived to modern times. Unfortunately, all others were lost in fire.

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– The professionals' solution to the problem.
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Tsume-Go Strategy 1 – Learn to Recognize Vital Points in Go Problems

Did you ever complain about Go problems that are much too difficult for you to solve? And probably lost courage? Inoue Dōsetsu Inseki’s advice — written down over 300 years ago — is to study shape. This book helps you do that and overcome your current weakness in the beautiful field of tsume-go.

Study over 300 problems — based on 47 corner patterns — that are analyzed in great detail. Absorb numerous hints that direct your gaze to previously unrecognized vital shape points.

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SmartGo Books, 2015
$9.99; 1,304 pages; 314 problems