© Copyright 2015 by Thomas Redecker

Tsume-Go Strategy

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 300 problems – based on 47 corner 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.

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Copyright Page

First edition.

© 2015, 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 47 (easier) corner patterns from another classic problem selection, the Gengen Gokyō, resulting in over 300 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 corner 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

Many thanks go to Marcel Grünauer who painstakingly proofread this book and worked very hard to polish my English. Paul Lalonde and Bill Spight were kindly assisting me with very helpful suggestions on “Lessons learned”.

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, December 2015
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

Problem 045

Problem 046

Problem 047

Appendix – An unimaginable shape point

Problem 048

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.

Excursus – Linear shapes vs. bulky shapes

Excursus – Dead eye shapes

Excursus – A descent to the edge of the board

Excursus – The 1–2 points in the corner

Excursus – How to defend a cutting point

Excursus – Real eyes vs. false eyes

Excursus – Adding a second stone for sacrifice

Excursus – Capturing two stones on the edge

Excursus – Cutting points reduce your options for connecting out

Excursus – Bent four in the corner

Excursus – Bent five in the corner

Excursus – One eye beats no eye

Excursus – Mind the environment

Excursus – Cutting a keima (knight’s move)

Excursus – Strike at the waist of a keima

Excursus – The art of reducing third-line territory

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

Excursus – Liberties in a bamboo joint

Excursus – Play hane on both sides for an additional liberty

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.

1–2 point

Atari

Attack

Capture

Connecting

Dead eye shape

Defence

False eyes

Inside

Knight’s move

Ko

Liberties

Moves

Outside

Sacrifice

Semeai

Snake

Snapback

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 from the corner), 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 “” / “”.

“●”

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.

“12”

12point

The 1–2 points in the corner (either occupied, or unoccupied) are marked with 12.

“✕” / “” / “”

falseeye

False eyes are marked with “✕”, the respective opponent’s 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 “✕” / “” / “”.

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 !!.

“◇”

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’s 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 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 White 1 (I)

  `-> 1   var. for White 1 (II)

  `-> 1   var. for White 1 (III)

 :        `-> 3     sub-var. for White 3 (I)

 :        `-> 3     sub-var. for White 3 (II)

3 continuation main line

  `-> 3   var. for White 3 (I)

  `-> 3   var. for White 3 (II)

  `-> 3   var. for White 3 (III)

6 continuation main line

  `-> 6   var. for Black 6

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
    > 1
    > 1
            > 3
            > 3
3
    > 3
    > 3
    > 3
6
    > 6

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 original problem) 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’s 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 () hasn’t.

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’s 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

＞＜ ▶︎

White 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
    > 1
    > 1
            > 3
            > 3
3
    > 3
    > 3
    > 3
6
    > 6

Next page: Hints

Hints

The maximum eye space that Black could achieve (●) is quite winding. White must be on her guard not to let it become unintentionally divided.

Please note that Black might be able to add an additional point to his potential eye space at the right, on the first line.

< Excursus – Linear shapes vs. bulky shapes >

A potential dead eye shape in the corner is marked with triangles (△).

Another potential dead eye shape marked (△).

You can understand the central point of these dead eye shapes as a kind of spotlight that might guide you to a vital point of the problem.

Please be well aware that there is no guarantee at all that every highlighted point can be taken successfully without thinking. Especially if there are several of these points – as A and B here – additional information is required to let you choose the right one.

< Excursus – Dead eye shapes >

Please note White’s descent to the first line of the board.

This kind of move often plays a decisive role in tsume-go, because it usually weakens the neighbouring position of the opponent to a large extent. It therefore might give you a hint which side to begin with.

In particular, it might become easier to connect seemingly enclosed stones to the outside. In this context, the opponent might fall prey to some kind of shortage of liberties when trying to intercept.

< Excursus – A descent to the edge of the board >

Black has already occupied the lower 1–2 point (Black 12) in the corner.

Usually, it is a bad idea to let Black get the other 1–2 point (12) on the left edge too. With stones on both 1–2 points, Black will have established an eye on the 1–1 point and might easily get a second one nearby.

< Excursus – The 1–2 points in the corner >

Black’s -stones are not solidly connected to each other but leave a cutting point at C.

You will notice that – here in this problem – the edge of the board is near, so that a white cut is no immediate threat. Additionally, there is Black’s stone on the first line, also serving to protect the cut.

< Excursus – How to defend a cutting point >

In this diagram, a “line of false eyes” is marked (, ✕).

If White eventually manages to establish own stones at both ends of such a line, it will result in a false eye of the opponent.

However, White’s supporting stones are positioned only on the third line, so it might become difficult to establish a permanent stone on the first line here.

< Excursus – Real eyes vs. false eyes >

Black’s partial groups on top have three liberties each, which is not very reassuring.

In addition, one of these liberties is shared by both groups, so there is the danger that these may fall prey to some kind of shortage of liberties.

< Return to the problem >

Next page: Solution

Solution 001

＞＜ ▶︎

White 1 jumps to the 1–2 point on the left edge.

White will succeed neither by pushing into Black’s corner at the left, nor by cutting inside.

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.

＞＜ ▶︎

Black has to intercept with 2. Otherwise, the potential size of Black’s remaining eye space (●) would not be large enough for two eyes, after having allowed White to connect her stone.

To be continued …

< Return to the hints >

< Continue with the solution >

Next page: Problem (follow-up)

Problem 001 (follow-up)

＞＜ ▶︎

In tsume-go, it is not sufficient to get the first move right. Very often, the first move of the solution (probably somewhat obvious) only serves as a kind of “appetizer”, or “door opener”, but the real challenge of the problem lies deeper. Therefore, here comes a follow-up problem.

White to kill.

< Continue with the solution >

Next column: Variation tree

1
    > 1
    > 1
    > 1
            > 3
            > 3
○ ● ○ ● ○ ● ○ ● ○
3
● ○ ● ○ ● ○ ● ○ ●
    > 3
    > 3
    > 3
6
    > 6

Next page: Hints (continued)

Hints (follow-up)

One prominent pitfall in this kind of position is a group that could be easily put into atari and so looks quite attractive at first sight.

Black’s -group on top has only two liberties (●), so there are two possibilities for White to give atari.

However, you should think at least twice before playing an atari! In particular if you are quite “early” in the course of the solution sequence.

It might not benefit you that this kind of move is absolute sente (in the overwhelming majority of cases your opponent cannot afford to lose their endangered group – but please take notice that there are exceptions to the rule!).

In the position above, White’s -stone has also only two liberties, and very probably will be massively weakened by Black’s answer. In addition, Black’s reply to such an atari that has been played “early” might serve to solidify his position decisively.

< Return to the problem >

Next page: Solution (continued)

Solution 001 (continued = follow-up)

＞＜ ▶︎

White continues with the somewhat surprising clamp of 3 on the first line.

White will succeed neither with an atari on Black’s three stones on the left (case 1, case 2), nor by blocking on the outside.

However, starting with this clamp, without having played the preparatory exchange on the left edge, would be too early, and so will fail as well.

Black desperately tries to enlarge his eye space, with moves at 4, and – after White’s block with 5 – at 6 (alternatively, Black might choose to play this move on the inside). But now Black’s right-hand group is the second one that has only two liberties.

＞＜ ▶︎

The cut of White 7 is double-atari now, leaving Black helpless. Black can only get one eye in the corner, and so is dead.

Variation for Black 6

＞＜ ▶︎

Alternatively, Black might try to give atari from the other side, with a move at 6 here.

＞＜ ▶︎

White will also give atari, with a move at 7, and Black is forced to connect at 8. With 9, White sacrifices two stones, instead of only one, …

< Excursus – Add a second stone for sacrifice >

＞＜ ▶︎

… eventually turning Black’s potential eye into a false one (11, ).

< Excursus – Capturing two stones on the edge >

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.

< Go to the next problem >

Next page: Failures

001 Problem (follow-up – failure I)

＞＜ ▶︎

White just played atari on Black’s three stones on top.

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.

Black to live.

< Go to the next failure >

Next column: Variation tree

1
    > 1
    > 1
    > 1
            > 3
            > 3
3
○ ● ○ ● ○ ● ○ ● ○
    > 3
● ○ ● ○ ● ○ ● ○ ●
    > 3
    > 3
6
    > 6

Next page: Solution

001 Solution (follow-up – failure I)

＞＜ ▶︎

Of course Black has to connect with a move at 4.

White can do nothing more than blocking the outside with 5, forcing Black to secure his second eye with a move at 6.

< Return to the hints >

< Return to previous choice >

Lessons learned

Think twice before giving atari!

Do not overlook that your opponent’s obvious answer move might serve to partition the winding potential eye space (●) of their group.

001 Problem (follow-up – failure II)

＞＜ ▶︎

White just cut inside Black’s formation, simultaneously giving atari to Black’s three stones above.

Black to live.

< Go to the next failure >

Next column: Variation tree

1
    > 1
    > 1
    > 1
            > 3
            > 3
3
    > 3
○ ● ○ ● ○ ● ○ ● ○
    > 3
● ○ ● ○ ● ○ ● ○ ●
    > 3
6
    > 6

Next page: Solution

001 Solution (follow-up – failure II)

＞＜ ▶︎

Of course Black will save his stones that are in atari, with a move at 4.

And again, White can do nothing more than blocking the outside with 5, forcing Black to secure his second eye with a move at 6.

< Return to the hints >

< Return to previous choice >

Lessons learned

Think twice before giving atari!

Do not overlook that your opponent’s obvious answer move might serve to partition the winding potential eye space (●) of their group.

001 Problem (follow-up – failure III)

＞＜ ▶︎

White just exerted pressure from the outside.

Black to live.

< Go to the next failure >

Next column: Variation tree

1
    > 1
    > 1
    > 1
            > 3
            > 3
3
    > 3
    > 3
○ ● ○ ● ○ ● ○ ● ○
    > 3
● ○ ● ○ ● ○ ● ○ ●
6
    > 6

Next page: Solution

001 Solution (follow-up – failure III)

＞＜ ▶︎

Black maximises his eye space with the descent of 4.

White can close the outside with 5 in sente, but Black 6 secures two eyes.

< Return to the hints >

< Return to previous choice >

Lessons learned

Playing from the outside might help your opponent with solidifying the borders of the potential eye space (●) of their group.

001 Problem (failure I)

＞＜ ▶︎

White just cut inside Black’s formation.

Black to live.

< Go to the next failure >

Next column: Variation tree

1
○ ● ○ ● ○ ● ○ ● ○
    > 1
● ○ ● ○ ● ○ ● ○ ●
    > 1
    > 1
            > 3
            > 3
3
    > 3
    > 3
    > 3
6
    > 6

Next page: Solution

001 Solution (failure I)

＞＜ ▶︎

Black connects his forces with a move at 2, simultaneously putting White’s cutting stone in atari.

＞＜ ▶︎

Now, White 3 on the first line, the final blow in the correct solution sequence, does not work any longer. In a real game, White would give atari at 4 instead, letting Black live with a move at 3.

Black 6 captures White’s cutting stone for an eye.

＞＜ ▶︎

White can prevent another eye on the bottom, …

＞＜ ▶︎

… and eventually White 9 turns this potential eye into a false one, but Black has a sure eye in the corner, and so is alive. Please note that White’s last moves are only shown for demonstrative purposes.

< Return to the hints >

< Return to previous choice >

Lessons learned

Do not overlook that your opponent’s obvious answer move might serve to partition the winding potential eye space (●) of their group, and – additionally – greatly weaken your cutting stone that you played “inside”.

001 Problem (failure II)

＞＜ ▶︎

White just reduced Black’s potential eye space from above.

Black to live.

< Go to the next failure >

Next column: Variation tree

1
    > 1
○ ● ○ ● ○ ● ○ ● ○
    > 1
● ○ ● ○ ● ○ ● ○ ●
    > 1
            > 3
            > 3
3
    > 3
    > 3
    > 3
6
    > 6

Next page: Solution

001 Solution (failure II)

＞＜ ▶︎

Black simply divides his potential eye space into two, with a move at 2, occupying both 1–2 points in the corner.

＞＜ ▶︎

As usual, White can close the lower side in sente, but Black will get a living formation.

< Return to the hints >

< Return to previous choice >

Lessons learned

Playing from the outside might help your opponent with solidifying the borders of the potential eye space (●) of their group, as well as easily partitioning it.

Avoid letting your opponent get both 1–2 points (12) in the corner.

001 Problem (failure III)

＞＜ ▶︎

White just played the clamp on the first line.

Black to live.

< Go to the next problem >

Next column: Variation tree

1
    > 1
    > 1
○ ● ○ ● ○ ● ○ ● ○
    > 1
● ○ ● ○ ● ○ ● ○ ●
            > 3
            > 3
3
    > 3
    > 3
    > 3
6
    > 6

Next page: Solution

001 Solution (failure III)

＞＜ ▶︎

White’s clamp simply was too early. Black responds with 2. White may consider continuing with A, B, or C.

＞＜ ▶︎

White’s jump to 3 comes too late now, because Black is not forced to intercept with a move at 5. He will play at 4 instead.

White saves her stone in the corner with 5, but Black manages to build two single eye points for the life of his group.

< Return to previous choice >

Variation for White 3 (I)

＞＜ ▶︎

Cutting with 3 does not work either. Again Black saves his group with the solid move at 4.

＞＜ ▶︎

In a real game, White might close the bottom, and not insist on making Black’s eye on the bottom false, with a move at 8, instead. Remember that Black has his third eye in the corner.

< Return to previous choice >

Variation for White 3 (II)

＞＜ ▶︎

Blocking from the right, with White 3 here, does not work either. Black 4 immobilises White’s stone on the first line.

White’s jump to 5 reduces Black’s territory in the corner, but again, the solid move at 6 is the match-winner for Black, as far as the life of his group is concerned.

< Return to the hints >

< Return to previous choice >

Lessons learned

Consider carefully whether your move (●) – positioned on the border between “outside”, and “inside” – might force your opponent to enlarge the potential eye space (●) of their group.

Problems 2 to 48 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 – Linear shapes vs. bulky shapes

Excursus – Dead eye shapes

Excursus – A descent to the edge of the board

Excursus – The 1–2 points in the corner

Excursus – How to defend a cutting point

Excursus – Real eyes vs. false eyes

Excursus – Adding a second stone for sacrifice

Excursus – Capturing two stones on the edge

Excursus – Cutting points reduce your options for connecting out

Excursus – Bent four in the corner

Excursus – Bent five in the corner

Excursus – One eye beats no eye

Excursus – Cutting a keima (knight’s move)

Excursus – Strike at the waist of a keima

Excursus – The art of reducing third-line territory

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

Excursus – Liberties in a bamboo joint

Excursus – Play hane on both sides for an additional liberty

Excursus – Linear shapes vs. bulky shapes

The kanji that are used in Japan for naming the game of Go – 囲碁 – “igo”, have the etymological meaning of “enclosure surrounding well – (by) carefully selected small stone pieces”. This also highlights the primary aim of the “surrounding game” (a shorter equivalent), which is to acquire more territory than your opponent.

In reality, you will want to use your stones in the most efficient way, i.e. to surround as many points as possible with as few stones as possible. This implies that you will prefer compact, bulky shapes for your territory.

Here, in this diagram, White has built a territory of 12 points in the corner by using eight of her stones.

Getting 12 points of territory in a linear shape, as shown here, needs the investment of some more stones (+). In total, White needed 14 stones here; the lack of efficiency will become evident.

However, this book is about the field of tsume-go, primarily working on questions of life and death. The amount of territory gained does not matter at all.

Let us illuminate this decisive difference with some tiny examples.

Here, in this diagram, White has used five of her stones to create a bulky shape in the corner that consists of four points. However, White has not created territory of her own because her group is dead.

It cannot get two eyes, even if White plays first (White A, Black B).

White would wish to have invested one more stone (+), here for creating a linear shape for her eye space, which consists of four points as well, and now is territory.

White is alive, because the points of A and B are miai for splitting her shape.

White would not prefer to build a bulky shape of five points with her six stones, shown here. The fate of White’s group depends on whose turn it is (and who will take the △-point).

Again, White could sleep much better – at the cost of only one additional stone (+) – if she had established sure five points of territory in a linear, straight shape.

Please note that this surplus seventh stone (+) would be also necessary to transform White’s bulky five eye space into a living one that is divided into two parts.

< 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 point

Atari

Attack

Capture

Connecting

Dead eye shape

Defence

False eyes

Inside

Knight’s move

Ko

Liberties

Moves

Outside

Sacrifice

Semeai

Snake

Snapback

Two areas

Zigzag line

1–2 point

Do not forget the value of the 1–2 points in the corner for making eyes, especially on the 1–1 point. Even small areas could be partitioned successfully.

Do not believe that every 1–2 point in the corner is always the initial clue to the solution.
Not every 1–2 point in the corner is a real vital point.
If both 1–2 points are still unoccupied, consider the order of moves carefully.

Avoid letting your opponent get both 1–2 points, so becoming the owner of the corner.
Do not force your opponent to occupy a 1–2 point in the corner if you cannot prevent the other one being also taken.

Your opponent will not allow you to occupy both 1–2 points in the corner.

< 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

Hwang In-seong 8d:

Yunguseng Dojang

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
$9.99; 805 pages; 1 problem

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.

“How do you eat an elephant?” is the usual management consultant’s reply when being asked how to manage a huge project.

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.

Enjoy a journey through time — look over the shoulder of Dosetsu and get a picture of how he composed his masterpiece.

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.

Among these the most difficult is #120, widely believed to be the most difficult Go problem ever created, which has still not been solved by professional Go players.

The long standing collaboration of three amateurs, from Germany, and the United Kingdom, has found the answer!

Get the whole story in two volumes. Over 1,100 pages in the hardcover edition!

Published in 2015.

– Our solution to the problem.
– Explains the general structure of the problem in large detail.
– Contains a large number of variations.
608 pages

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– The professionals' solution to the problem.
– Contains all the variations that are known to us.
– Gives deep insights into the ups, and downs, of our research.
– Explains several structural elements of the problem in great detail.
496 pages

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