All About Thickness - Ishida Yoshio

All About Thickness Understanding Moyo and Influence

by Ishida Yoshio, 9-dan

translated by Stuart Dowsey

The Ishi Press, Inc. Tokyo

Published by The Ishi Press, Inc. CPO Box 2126 Tokyo, Japan

© Copyright 1990 in Japan by The Ishi Press, Inc.

All rights reserved according to international law. This book or any parts thereof may not be reproduced in any form without written permission from the publisher.

In North America this book may be ordered from: Ishi Press International 1400 North Shoreline Blvd., Building A7 Mountain View, California USA 94043 ISBN 4-87187-034-0

First Printing April 1990 Printed in Japan

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About the Author Ishida Yoshio was born in 1948 in Aichi prefecture. He became a disciple of Minoru Kitani at the age of 9. He became a professional shodan in 1963 and was promoted rapidly thereafter. In 1971, he defeated Rin Kaiho in the 26th Honinbo title match to become the youngest Honinbo in history and held the title for five succesive terms. In 1974, he defeated Rin in the 13th Meijin title match, thus becoming the third contemporary player, after Sakata and Rin, to hold the top two titles concurrently. In recognition of this feat, he was promoted to 9-dan. Ishida has also won and challenged for many other major titles and is recognized as one of the leading players of his generation. He is an outstanding all-round player but is particularly skilful at overall positional judgment and at the endgame. In this regard he is know as the 'computer'.

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Contents Foreword Translator's Notes Example 1 Connect Up the Star-points Example 2 Blockade The Enemy Example 3 The Attach-and-Extend Joseki: A Good Example of Thick Shape Example 4 Thickness and Extensions from a Star-point Joseki Example 5 Keep Your Nose in Front Example 6 The Large-Scale Push Example 7 Make Thickness During the Opening Example 8 The 3-3 Invasion Example 9 Creation of Thickness Requires Flexibility Example 10 Variations on a Joseki Designed to Take Outside Influence Example 11 The Power and Range of Thickness Example 12 Pincers and Extensions Example 13 Attack or Defense Example 14 The Grand Sacrifice Example 15 The Enemy's Vital Point is My Vital Point Example 16 Combining an Extension with an Approach Move Example 17 Use Thickness in Your Strategy Example 18 In a Case of Opposing Thicknesses, First to Play Has the Advantage Example 19 Take Territory While Attacking Example 20 Protecting the Cut is a Thick Defense Example 21 Choose a Thickness Joseki According to the Corner Situation Example 22 The Ladder and the Outward Facing Joseki Example 23 The Ideal-Thickness Trap Example 24 Taking the High Ground Example 25 Thickness and Profit in Simple Versions of the Taisha Joseki Example 26 One Line Can Make All The Difference Example 27 Maneuvering For a Territorial Moyo Example 28 Pushing Out to Utilize the Sanren-sei

vi vii 2 6 10 14 18 22 26 30 34 38 42 46 50 54 60 64 68 72 76 80 84 88 92 96 100 104 108 112

All About Thickness Example 29 Inviting the Opponent Build Thickness is a Grave Error Example 30 How to Make Territory and Thickness in Actual Play Example 31 The Balance Between Territory and Thickness Example 32 Turn a Wall Into Large-scale Real Territory Example 33 Clear-cut Spheres of Influence and Settled Territory Example 34 The Perfect Solid Connection and the "Thousand Dollar' Bend Example 35 The Early Bird Catches the Worm Example 36 Don't Get Too close to Thickness Example 37 Playing at the Boundary of Influence Example 38 Play in the Corner and Build a Large Moyo Example 39 The Point That Connects in Three Directions Can't Be Bad Example 40 Imperfect Thickness Can Be Erased Completely Example 41 Thickness as the Basis of Large Moyos Example 42 Eliminate the Cutting Point Example 43 Cover the Center With Thickness Example 44 The Capping Move and Thickness Makt Good Partners Example 45 Widen Your Horizons 'Thickness' in Go Proverbs Index: Types of Thickness

v

116 122 .126 ,130

134 138 142 146 150 154 158 162 166 170 174 .178 .182 ,186

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Foreword What is thickness? Ifs difficult to define in just one sentence. If forced to, we could say it is the power of solid, secure stones. Beginners can understand the concept of territory with relative ease. Moreover, they can count the number of points in a piece of territory more or less accurately. However, it is much more difficult for them to handle and use what is called thickness or thick shape. As regards thickness, large territories can be made in its immediate vicinity, thickness can aid attack on an opponent's weak stones and in other circumstances, its power enables the creation of new territory elsewhere. This explanation is straightforward, but words alone are inadequate. For this book, we have chosen situations that occur frequently in actual play, in joseki and in the fuseki, in even games and in handicap games, to develop in the reader an intuitive grasp of the subject and to show him how to use thickness, how to make thickness and how to cope with an opponent's thickness. Also, as it is useful to know how many points thickness is worth, we have touched on this subject to a limited degree. Ishida Yoshio, 9-dan December 1985

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Translator's Notes The term 'thickness' is a direct translation of the Japanese word 'atsumi'. Its use in the game of go is quite specialized and not readily understood. The nearest equivalent is 'strength', but it is that special strength which radiates from a strong connected position into empty areas nearby. Perhaps a brief explanation, starting from basic principles, will help. Every stone placed on the board is in direct relationship with the adjoining points, its liberties. By placing a friendly stone on any one of these adjacent points, stones can be connected together. If the adjacent point is occupied by an enemy stone, the number of liberties and the directions in which connections can be made are correspondingly reduced. However, the same single stone also exerts an effect on the other surrounding points. The further from the stone the weaker this effect is. A stone situated by itself, in isolation, will have an equal effect in all directions. The presence of other friendly stones nearby add to this effect or in the case of enemy stones detract. When this effect is unimpeded we say that the stone or stones are strong and vice versa. The strongest positions arise when stones are securely connected together. Connected stones combine their effect and have a strong influence on the surrounding area. The larger and more secure a group of connected stones is, the greater its influence will be. However not all strong positions are called thickness. This term is reserved for lines of connected stones at right angles to the edge of the board and quite often walls of stones facing in towards the center. When the strength of such a position has a significant effect on adjoining areas and must be taken into account, it is referred to as 'thickness'.

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Proper use of thickness in games is most enjoyable. This book contains examples of every conceivable type of thickness making that pleasure attainable by more and more players. Stuart Dowsey March 1990

Glossary aji: potential aji-keshi: erasing or destroying potential atari: the threat to capture a stone or a group of stones on the next move. byo-yomi: overtime. The time given a player (usually 30 seconds or 60 seconds per move) to complete his move after his clock time has run out. furikawari: a trade, a swap fuseki: the opening hane: a diagonal move played against an enemy stone joseki: a standard pattern of good play (usually in the corner) moyo: territorial framework — potential, not actual, territory sabaki: settling a group by making a flexible and resilient shape sensei: literally 'teacher'. Professional go players are usually referred to as sensei. tesuji: the most skilful move in a local situation

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All About Thickness Understanding Moyo and Influence

Forty-five examples from handicap and non-handicap games, graphically teaching you how to build thickness and the fundamental principles of how to use it once you have constructed it

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Example 1 Connect up the Star-Point Stones

Settled territory

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Playing here is misdirected.

3

The settled territory here isn't very large.

4

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Dia. 1. In 5 or 6-stone handicap games, Black has to utilize his handicap stones from the beginning in such a way as to constantly outdo White. This is the actual sequence leading to Example 1. The pincer of Black 2 is a positive move. After the double approach by White 3, attaching and extending with Black 4 and 6 is easy to follow. After White 7 —

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Dia. 2. The steady block of Black 1 leads to a simple, elegant joseki. Following White 2, Black wedges in and connects with 3 and 5 which is the thick way of playing. In contrast to White's many cutting points, Black hasn't a single weak spot. If White plays 6 at 'a', followed by Black V , White V, Black 'd', once again Black gets thickness.

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Example 2 Blockade the Enemy

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This sanren-sei isn't bad, b u t . . .

The black and white strengths overlap.

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Dia. 1. This is the start of the sequence which leads to the previous diagrams. After White 3, Black splits the white stones with 4. The double approach by White 5 is quite a common tactic. Black then plays contact with 6, extends out with 8 and looks for a way to create thickness.

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Dia. 2. If White pushes in towards the corner with 1, Black is almost certain to play the bamboo joint of 2, as this is the thick way of playing. Taken as an isolated situation, Black will play 'a' after White 3, but in this context, to utilize the marked pincer stone, he will bend round at V and blockade White on a large scale.

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Example 3 WMMMMMBMM—MMMMMMMMMM

The Attach-and-Extend Joseki A Good Example of Thick Shape

Anywhere around here is big.

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harmony and balance.

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Dia. 1. Following White's extension to his marked stone, the one-space defense by Black 1 is steady and reliable. White can now enter the lower side with a midway placement at 2 if he wishes. Black 3 blocks White off from the right White 4 is inevitable, even though he has to accept the diagonal contact play of Black 5. The sequence to Black 7 is to be expected and represents a satisfactory development

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Dia.2

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Dia.3

Dia. 2. Going back to the example diagrams, Black might not feel able to extend as far as the marked stone if he doesn't know how to handle White's counterattack, the push through and cut of White 1 and 3. The descent of Black 4 is sente threatening a cut at 'a'; 5 is White's strongest response, but Black seals him in with 6 and 8. Dia. 3 The diagonal move White 1 may look disconcerting, but Black simply descends to 2. When White jumps to 3, the wedge in by Black 4 is a tesuji. The sequence up to White 9 leads to ko after Black's atari at 'a'. As Black has the cut at V to provide him with ample ko threats, he cannot lose. If White plays 5 at 9, Black can then atari from 7 and again is in no danger.

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Example 4 MHHHMHaBMMMMMMMHHUMMM

Thickness and Extensions from a Star-Point Joseki

The right point is around here.

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A good extension, achieving both vertical and horizontal balance

15

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Dia. 1. Black can also consider playing the high extension at 1 but this is vulnerable to a deep invasion. For example, the invasion at 'a', the peep at White V in combination with 'c', and so on. In many instances, when building a position on the fourth line, it is necessary to be aware of possible invasions on the third line.

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Dm. 2. The lower move, Black 1, will probably result in the capping move White 2 but Black's reply at 3 is quite adequate. White 2 is well inside the sphere of influence of the marked stones, so sabaki will prove difficult. When surrounded by reinforcements, the low extension of Black 1 has great territorial potential.

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Example 5 Keep Your Nose in Front

The sequence in this corner follows a standard handicap joseki.

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Black is virtually guaranteed 30 points of settled territory.

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Dia. 1. In this situation, White can further enclose the right side with moves such as 1 and 3. To make counting easy lefs assume White 'a', Black 'b'', after which White's territory on the right side is worth about 30 points. This is equal to Black's settled territory on the lower side, but remember White only has one position on the right while everywhere else is Black's.

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Dia. 2. Many players might play Black 1 to reduce the thickness of White's two marked stones. However, this allows the hane of White 2 and is a mistake. The shortage-of-liberties trap White 'a', Black 'b', White V now comes into play. To avoid this, Black had better play 3 at 4, which, though bad shape, is the only way to fight back.

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Example 6 The Large-Scale Push

The white territory here is about 10 points.

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The shaded area could be as much as 30 points

23

This white area is still only 10 points or so.

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Dia. 1. Black 1 is considered the proper move as it prevents White coming to the aid of his isolated stone with a jump out to 'a'. Black can expect to get territory between the dotted line and the edge. However, if you want a really large-scale utilization of the black star-point stone on the right side then play as in the previous diagram.

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.:.-.-.»:«.>-.V'-->»--r'V.:--Xj'>-o.t.r.:.:.>-.:.:o>-.-.-.:

Dia. 2. This is the actual sequence which produced the example position. The sanren-sei of Black 4 is a fine move. Black could equally well have played the large knighf s move at 'a'. Black 6 is also good. The 3-3 of White 7, leading up to White 15, is a common joseki. After this, Black 'b' is the way to make thickness.

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Example 7 Make Thickness During the Opening

The sequence in this corner follows a standard star-point joseki.

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The one-space jump here instead Black 1 is a bit weak.

27

Pressing down with B l a c k 1 is ver y severe-

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Dia. 1. This is a possible continuation. Once Black has pushed ahead as far as the marked stone, White may choose the capping move of 1, a familiar tactic, but once again the proverb 'answer the cap with the small knighf s move' proves appropriate. White is going to find sabaki in the middle of Black's sphere of influence hard to come by, while Black still has the blocking move of 'a' as a treat to look forward to.

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Dia. 2. Returning to the earlier sequence (page 27), White may counter Black 1 with the push through and cut of 2 and 4, but this is nothing to be afraid of. The battle will unfold from Black 5 to 11 and thereafter White will forever be anxious about the situation around the two stones 4 and 6 lest they be ensnared by Black.

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Example 8 The 3-3 Invasion

White's territory is 6 points.

Up to Black 6 is a typical joseki.

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immediately

White's territory is 6 points.

This block is the only forcing move.

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Dia. 1. Here is another example of the 3-3 invasion when Black has played the one-space jump. After Black 2, the hane and connection of White 3 and 5 is normal. White 3 at 'a' is a bad mistake, as the block by Black 'b' is nigh perfect.

Dia. 2. The slide to White 1 is the right move. Black can stop White at 2. The sequence up to Black 8 is one joseki. Compared with White's 7 points in the corner, Black's outer thickness is extremely powerful.

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Dia. 3. The 3-3 invasion by White 1 is not so good against Black's small knighf s shape. One has the sense of burrowing away in a tight little spot. It is quite different from the large knighf s shape and life will be very restricted.

Dia. 4. Black blocks confidently at 2. After White 5, Black has the highly efficient small knighf s connection at 6 to make his thickness almost impregnable. Set against White's 7 points in the corner, Black is even less worried about White 'a' than in Dia. 2.

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Example 9 »—0—WWM——W—BWBW5BWC

Creation of Thickness Requires Flexibility

Start with this atari.

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Black 8: captures

Black has sente.

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Dia. 1. If White plays 'a' and so on after Black 1, as seen in the previous diagrams, he allows Black substantial thickness, so perhaps this is the moment to think again. How about giving up the chance of capturing two black stones in the corner and sacrificing two white ones instead?

Dia. 2. The more correct way to proceed is push out at White 1 and take away Black's liberties. Then White 2 would put Black on the spot. Black is forced to play 2 to capture the two stones, White extends to 3 and finishes with a satisfactory shape. In consideration of this, Black had better choose the alternative answer to the crosscut, as shown in the following diagrams.

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Dia. 3. After the crosscut of White 1 and 3, Black typically strengthens himself with 4 for a far more peaceful joseki. The proverb says 'Against the crosscut, extend'. Now there are no complicated variations.

Dia. 4. White will play atari at 1, followed by the double open connection at 3. Black must take the crucial point 4 to safeguard the corner. Black 6 brings this episode to its natural conclusion. Black has a secure position, and White, through the sacrifice of one stone, has taken sente.

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Example 10 Variations on a Joseki Designed to Take Outside Influence

White's territory is about 10 points.

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This is to prevent Black getting outside influence.

Whichever way he pushes, his stones get tangled up.

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Dia. 1. To avoid the trap laid in the previous diagram, after White 4, Black 'a', White 'b', Black V gives a good result, but Black 5 straightaway is much easier to grasp.

Dia. 2. The ensuing moves to Black 8 form one pattern. Black hasn't constructed thickness, but he is satisfied to have positions along both edges.

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Dia. 3. Up to Black 5 is the same as Dia. 1. However, in place of 'a', White has simply played the contact move at 6.

Dia. 4. Black pushes out with 1, followed by atari with 3 and 5. The outward influence gained here is even thicker than that shown in the initial diagrams, so Black has done well.

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Example 11 The Power and Range of Thickness Against White 1, Black 2 to 12 produce thickness.

The value of the star-point stone is 10 points.

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White has 6 stones. Black has 7 stones.

stone than White, his area can be thought of as about 20 points.

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Dia. 1. Taking the thickness in the upper left corner as our starting point, Black can develop his position as far as the marked stone. The reasoning behind this relates to a white entry at 1. Because White is unable to make a two-space jump in the direction of the arrow, he cannot get a stable base on the side. A deep invasion such as White 1, given insufficient room to make a two-space extension, is very dangerous. That is why Black can develop as far as the marked stone.

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Dm. 2. In view of the strength of his thickness, Black might also consider extending as far as this marked stone. However, if White now invades at 1, he has sufficient room to make the two-space extension to 'a'. For this reason, as a general rule, Black will count 5 spaces from the leading marked stone in the wall to V to find the limits for an extension. Moving away somewhat from this example, we find the same principles apply when making pincer moves against enemy stones. So as not to allow the opponent to make a twospace extension, the limit is set at a three-space pincer. Four spaces left open would allow room for a two-space extension, so such a move would not qualify as a pincer.

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Example 22 Pincers and Extensions

The full extension serves also as a pincer.

Narrower extensions ^axe not good.

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If it were White's move, he would play this extension.

The two-space extension is appropriate.

This is too far.

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Dia. 1. For White to extend with 1 to 'a' comes too close to Black's thickness. Black could then aim at the invasion point of V. Even though it may be a little limited, the two-space extension of White 1 is the right move. Black will probably play the diagonal contact move at V, and White has no option but to extend up with 'd'.

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Dia. 2. White might think of the slide into the corner with White 1 before extending, because if Black answers at 'a', White 'b' is ideal. However, Black is unlikely to answer with 'a'; instead he will choose the pincer at 2. The black position after White 1, Black 'a', White V is without merit.

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Example 13 Attack or Defense

This move utilizes Black's thickness, and also acts as a pincer against White.

-four" across

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If White were to play first, he would play a three-space extension.

According to circumstances, this move is also possible.

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Dia. 1. When Black, using the formula '3 up, 4 across', extends four spaces with 1 from his three-stone wall, this becomes a three-space pincer against the marked stone, a good move which kills two birds with one stone. Faced with the squeeze, White can play the sequence from the diagonal contact at 2 up to 6 in order to settle himself.

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Dia. 2. If White chooses to neglect the marked stone by playing elsewhere, Black can play the diagonal-contact move of 1, followed by 3. As the two white stones have no secure base and are under attack from Black 3, things are looking very difficult for White.

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Example 14 The Grand Sacrifice This is 'Kaizen's Great Masterpiece'.

An evaluation of Black's outside thickness is difficult but it is correct to say that Black's position is superior to White's settled territory.

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This is the start of the sequence which leads to the previous diagram.

An aggressive block

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Dia. 1. Continuing from the previous diagram, after Black cuts with the marked stone, White is able to pull out to 1 because he has a stone at 'a'; if the ladder didn't work he wouldn't have been able to play here. For example, after White 1, Black 7, White 6, Black 10, Black can start the ladder with V . Suzuki Tamejiro, honorary 9-dan, commented that it would have been better for White to play 11 simply at 13.

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Dia. 2. Black plays atari at 1, followed by the capture of 3. If White plays 4 at 'a', he can capture five black stones, but it would be enough for Black to capture at 4 in sente. Similarly, after the loose geta at 5, if White plays 'a', Black can force replies to 6 and 12 to build a flawless wall in the center. As these results are bad, White resists with 6 in an attempt to hack his way out into the center.

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Dia. 3. Yet again Black produces an exquisite loose geta at 1. White plays atari after atari from 2 up to 8 in the hope of eventually breaking out into the center. Black plays 11, which, while reducing White's liberties, seems to knock him on the head. White's retreat from 12 to 16 is galling.

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Dia. 4. Black plays the forcing sequence from 1 to 5 and finishes up with the capture by 7 of one white stone in the center. Thickness billows out like towering clouds, wondrous to behold. Kaizen was a monk at Zojoji Temple in Sanenzan Mountain, Shiba. He was an extremely strong 5-dan with no professional status but on a par with Shinomiya Maizo and Sekiyama Sendaiu.

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Example 15 The Enemy's Vital Point is My Vital Point

five across

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White to play this extension.

The enemy's vital point is my vital point

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Dia. 1. Faced with the attack by Black 1, White will settle himself with moves such as the diagonal contact move of 2 , then 4 and 6. After Black 7, White has two ways to reduce the black area: either lightly with 'a' or more forcefully with the shoulder-hit at 'b'. A deeper penetration at 'c' is out of the question because of the presence of the marked stone.

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Dia. 2. The standard 5-4 point joseki ends with Black 7. Applying the extension rule '3 up, 4 across', Black's threestone wall with 3 and 5 should provide the basis for a fourspace extension by Black 7 as far as 'a'. However, Black 'a' allows White the small knighfs move 'b' and next the quite severe invasion at 'c'. To guard against this would require an extra move, one which negates the purpose of the extension. Although Black 7 is one line narrower, ifs a very thick and reliable extension. Moreover, in Example 15 Black chose to play 7 as the small knighf s move at V and it was that shape which decided the ultimate extension.

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Example 16 WMMMMmmaHMMBMBMWWWWW

Combining an Extension with an Approach Move Black to play

A three-high wall gives a three-stone thickness.

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Black 1 is a four-space extension in keeping with '3 up, 4 across'.

Four lines

The '3 up, 4 across', four-space extension is a good point

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Dia. 1. Black can also give serious consideration to the approach move 1 to prevent White making a corner enclosure. White now needs to stop Black extending to 'a', but White 2 is as close as he can come to the wall. Black makes good his position with 3, getting another fine result The choice between the two is a matter of taste.

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Dia. 2. After Black 1, White might try to order Black about with the contact move of 2. If Black responds with 3 and 5, then he has done White's bidding. In addition to settling the corner, White can play 6 on an ideal spot which is both an extension and a pincer move. It is better for Black to extend with 3 to 6, in which case the exchange of Black 1 and White 2 is counted as a black forcing move.

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Example 17 Use Thickness in Your Strategy Black 1 to 5 is a splendid development

Strong thickness The wily 5-3 point

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Black is satisfied with his structure.

Pressing from above is a good method.

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Did. 1. The 3-4 point of Black 1 is of course another way to play. While standing a little further from the thickness on the left, this move uses that thickness indirectly while getting profit in the corner. The midway placement of White 2 is a calm move, to which Black plays 3 and White 4. If White decides to approach the corner stone instead of 2, Black will play a pincer move backed by this thickness.

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Dia. 2. The 5-3 point of Black 1 is a little too contrived and is somewhat unsuitable. White 2 is a good point; after Black 3, White's extension to 4 is well away from the black thickness on the left side. In other words, Black has just been reduced in strength, so this is unsatisfactory.

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Example 18 In the Case of Opposing Thicknesses, »W9BBBQ«QBWW«Bg«QQB9BB0«9M999BBmBBBJBBBQ«BBBBBBBBBBBBMBB«BBB«PBM

First to Play Has the Advantage White to play:

Prospects of about 30 points

Good aim

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Black to play: he can extend as far as this.

White's moyo has been sharply reduced.

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Dia. 1. The black one-space enclosure in the lower right corner is by no means weak and has quite a powerful effect along the lower side. For this reason, Black 1 isn't overextended, and when White invades at 2, Black can fight back satisfactorily with 3. The slightly more restrained Black 1 at 'a' is another fine move.

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Dia. 2. The high extension to White 1 is a bit problematic. There are two bad aspects. Firstly, because White 1 is a little too close to the influence of the two marked stones, it amounts to a duplication of effort. Secondly, as Black can slide underneath with moves at 'a' and so on, it is a bit weak territorially.

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Example 19 Take Territory While Attacking White to play:

White's thickness to the left is reduced.

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The close pincer works

This stone seals off White's boundary and stops Black's entry.

The only move

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Dia. 1. After the pincer of White 1, Black is likely to poke his head out at 2. White will push up again at 3; by attacking like this he transforms the lower left thickness from a territorial moyo into real territory. White could also play 5 at 'a'. A two-space pincer at 'b' instead of White 1 is a little on the

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Dia. 2. If, for argument's sake, Black were to play first, then the two-space extension to 1 would show correct judgment. To extend any further to the left would only invite an invasion. From Black's point of view, the long-range reduction of White's thickness in the lower left is quite satisfactory.

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Example 20 Protecting the Cutting Point is a Thick Defense If White has a stone on any intersection •

• ^

also be here.

-

^

—

—

•

i

•

i

•

•

i

-

III.III.III

U

•

i ...I

•

|

i his is an excellent move to defend against White "A'.

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The two-space extension is very secure.

An unbroken wall of thickness

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Dia. 1. White 1 may have been played to reduce black thickness as much as possible but it is somewhat over-extended. As White has come so close to the thickness of the marked black stone, Black's invasion at 2 hits the spot White won't be able to fight effectively.

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Dia. 2. In a case where the ladder works, the cut of White 'a' being successfully countered by Black 'b', the defense just seen would be omitted in favor of an extension up to Black 1. This is an example of 'Attack linked to defense'. Black 1 could also be played back at V.

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Example 21 Choose a Thickness Joseki According to the Corner Situation This pincer is to

Black's profit

This joseki works when there is a white stone in this corner.

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If this were Black, the joseki wouldn't be used.

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Dia. 1. White plays the marked pincer stone with the backup of a white stone in the corner. If Black decides to get his stone out into the open, White will attack by capping him with 2. Against Black 3, White plays 4 and now has the possibility that the left side will become territory. This result was possible because of the thickness on the upper side. The balance between thickness and territory is very important.

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Dia. 2. If earlier, after White had pressed Black down along the upper edge with 1 to 5, Black wished to avoid White's pincer, he could have extended to 6 or 'a' down the left side. White wouldn't miss the chance to play the thick block at 7. In this case, White has made thickness toward the upper right. This is quite different from the previous diagram and will lead to a different game.

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Example 22 The Ladder and the Outward Facing Joseki The cutting stone is captured

If a white stone lies on any of these intersections, Black's ladder will not work.

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The cutting stone is captured.

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White gets the outside.

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Dia. 1. When Black, in face of the push by White's marked stone, doesn't want to answer directly, he can play the diagonal to 1. Then again, he can play elsewhere. After this, White and Black exchange 1 and 2. Black's position may seem a little flattened, but his corner territory is secure while White has made outside thickness.

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91

(Wo,

Difl. 2. If White doesn't play the push at 'a', then 1 becomes the vital point for Black. If White replies with 'b', then this Black 1 becomes a forcing move. In addition to territory in the corner, Black has gained influence along the upper side. In the ensuing fight, the white position can still be attacked.

92

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Example 23 The Ideal Thickness Trap

with White's eyesight? What can he be thinking of?

All About Thickness

If you remove the same number of black and white stones from inside, this is exactly the same as the previous shape. Six black stones have been removed.

Six white stones have been returned to the opponent

93

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94

Dia. 1. The usual response to Black 1 would be either White 8 or 3 but the indirect reply at White 2 is a famous trick from ancient times. To an inexperienced player, this would seem too good an opportunity to miss, so Black pushes down with 3 and blocks at 5. Once White pushes out and cuts with 8 and 10, if s too late for Black to pull back.

Dia. 1

Dia. 2 8: connects

Dia. 2 After Black 13, the slide into the corner in the previous diagram, White pushes down at 1 and cuts at 3. Against Black 4, White plays 5 and the first stage of the sacrifice strategy unfolds. This sequence has become a one-way street; Black cannot avoid being caught in White's web of intrigue.

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Dia. 3. White now turns his attention to the right side with the block at 1. Black descends to 2, whereupon White plays 3 and 5 to enclose Black in an ever-tightening noose. Even Black 6 offers no reprieve. Black is forced to occupy the remaining liberties as White cracks his whip with 7 and 9. Finally, with the exchange of White 'a' for Black V, Black has been completely tricked.

Dia. 3

Dia. 4

Dia. 4. Ifs very easy to sidestep the trap. After pushing down to 3, Black calmly steps back with 5. White plays 6 to defend against 'a' and Black embraces the left side with 7. White's position on the upper side is kept low while the white stone on the left side is under pressure and almost surrounded.

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96

Example 24 Taking the High Ground The lower right corner

To extend to here instead of White 8 is uninteresting.

97

All About Thickness

In this position, it is White to play. In one bound, the jump takes control of the game.

This area has increased.

This black area has been reduced.

98

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Dia. 1. In actual play, the position in the lower right was arrived at. The jump of White 1 has come to occupy a crucial point and exert profound influence towards the center. If Black replies with 2, the right side almost certainly becomes black territory but in comparison, White 1 is a much larger-scale move, in a class of its own, affecting as it does the upper side down to the center.

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99

Dia. 2. If White, instead of playing the jump in the previous diagrams, decides to go for settled territory along the left side, Black now expands his influence with 2 and 4. The sequence to Black 8 can be expected and this time it is Black who has taken the high ground and whose game is on the larger scale.

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100

Example 25 Thickness and Profit in Simple Versions of the Taisha Joseki

This ends the sequence

OpWended position

All About Thickness

With this move, Black takes territory.

101 A different version of the joseki in which Black takes profit and White is granted thickness.

his is

Black and White have used the same number of stones.

102

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Dia. 1. After White 1 to 7, Black can cut at 8 to produce another simple version of the Taisha. Black neatly avoids White's provocation which could have led to more tortuous and convoluted variations of the joseki.

Black 4 takes ko (to left ofl); Black 6 connects (to left of 2) Dia. 2. White captures at 1 and by 7 this stage has ended. Viewed locally, White's position is superior but then as Black's aim was simplicity, this can't be helped.

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Dia. 3. Another version of the joseki, which avoids complicated variations, starts with Black playing 2, a solid connection, after White 1 and leaves the points of 'a' and 4 as miai. This version is hardly ever seen nowadays as it gives White a much better shape than the joseki in Dia. 4. White can also restrict Black severely with V.

Dia. 4. Lef s have a look at another joseki, which starts with White 1, proceeds to Black 4, and which resembles Dia. 3 somewhat. The result is even, but this time White cannot pin Black down with 'a'.

104

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Example 26 One Line Can Make All The Difference This is the only move for White. 4 rows

5 rows

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One line lower brings problems.

106

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Dia. 1. This is the sequence which leads on later to Example 26; it gives us another example on the lower side of the impact of thickness. The strength of White's three-stone wall, comprising White 8, 10 and 12, points to a four-space extension to the strategic point of 'a', following the maxim 'three up, four across'. However, Black has prevented this.

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Dia. 2. To continue, White plays the first move of the Taisha at 1, Black avoids unnecessary complications with 2 and 4, and by 10, we have an example of a joseki which produces profit for Black. On the other hand, White has built thickness in the result up to 9. The example presented in the previous pages dwelt on how best to utilize this thickness.

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Example 27 Maneuvering For a Territorial Moyo It is White's move and he should make

This approach is the only move.

The original sequence to produce this joseki is shown on page 110.

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109

This extension misses the point

He reduces White's thickness in a controlled way.

110

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Dia. 1. The sequence from White 4 up to Black 9 also appeared on page 109. White connects at 10 and from 12 to 16 strengthens his thickness toward the lower side.

Dia. 2. Following White's good approach with the marked stone, Black counters with 1 and the crosscut of 3, intending to make White over-concentrated in relation to his right-side thickness.

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111

Dia. 3. When White takes on the black stone with 1, Black settles things with the atari at 2. White's lower side thickness becomes settled territory, but Black has achieved his aim of restricting White's development. Now Black plays 4 and 6 to get a good development on the left After this, 'a' becomes a vital point in the contest between the two moyos.

112

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Example 28 Pushing Out to Utilize the Sanren-sei The small knighf s

Sphere of influence

All About Thickness This becomes White's sphere of influence.

This move heralds the disintegration of Black's strategy.

113

114

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Dia. 1. If, after the exchange of the two marked stones, Black plays the approach move at 1, this too marks a breakdown in his strategy. When White bends round the corner at 2, this is very thick move and occupies a make-or-break point for both players. By taking liberties from Black's three stones, White's thickness becomes stronger.

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Dia. 2. In other words, Black must not miss the chance to play 1. At this point, White can turn his attention to the lower side and play 2. Against this Black has three alternatives: the small knighfs move at 'a'; enlarging his moyo with Black 'b', then White V, followed by Black 'a'; or he could leave the lower side and block White's path along the upper side with

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Example 29 Inviting the Opponent to Build Thickness is a Grave Error This white move takes territory while directing Black to build thickness.

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118

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Dia. 1. If, after White has played the shoulder-hit with his marked stone, Black pushes at 1, White simply jumps to 2 and brings pressure to bear on the isolated black stone in the lower left corner. Next, when Black plays 3 to turn his thickness into a large moyo, White will play the high approach at 4, each player going his own way.

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Dia. 2. In these circumstances, the capping move of White 1 is inappropriate for the reduction of Black's thickness. Black answers with the small knighf s move of 2 which brings help to Black's marked stone in the lower left and seems to consolidate Black's left-hand territory on a larger scale. Moreover, White 1 itself is too close to Black's thickness on the upper side.

120

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Dia. 3. Lef s look at the sequence which led to White's territorial strategy. The sequence of White 4 to 12 in the lower right is a joseki. Black plays 13 in the center of the left side to draw together the stones in the niren-sei. Up to this point, there is nothing special to comment on in this development.

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Dia. 4. White's choice of the irregular corner enclosure with 1 signalled the start of his territorial strategy. White's plan is to tempt Black to play 2 and then immediately invade at 3-3 with 3. Had White 1 been played at 'a', Black at 'b', White 2, followed by Black V, this would have oeen another game altogether. Black 4 blocks from the right direction, White plays 7, and 31a"k continues with 'a' and so on.

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Example 30 BBBIBKBBBBIBBBIBBBBBBBBBBBBBBBBBBBflBMBBBBBI

How to Make Territory and Thickness in Actual Play

resisted White's invitation.

will start the Taisha with T7

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White 1 to 13 follows one joseki.

White has a strong sphere •

•

•

i I.M--

•

•

•

S r

Black's territory is about 15 points.

MI

A

I.

•

ii

•

•

•

i

i

i

The value of White's entire field of influence is about 25 points.

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Dia. 1. After Black has played his marked contact stone in the joseki sequence shown in the previous diagram, it is a mistake for White to block at 1. Black cuts at 2 and White is at a loss. For example, White 'a', Black V , White 'c', Black '&' and White's position is in tatters. Deviate from the joseki and you risk getting neither territory nor thickness.

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Dia. 2. The last move in the lower left corner, the block of White 'a', is a very important point for the completion of thickness. Neglect this move and play White 1 on the other side of the board, for example, and Black will jump out at 2, so White's thickness is left incomplete. Never leave a job half done.

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Example 31 The Balance Between Territory and Thickness Black to play

This thickness is the focus of the game.

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Now White has made about 15 points of territory

127

Though weak on . territory, this move

The black move reduces the thickness of the two marked white stones.

128

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Dia. 1. How about the black approach move at 1? White replies with the large knighfs move at 2 to give him good balance along the left side. The six-space gap between White 2 and the marked stones is virtually territory. It has to be said that Black's fuseki is unsatisfactory.

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Dia. 2. Apart from the shoulder-hit in the actual game, Black could have approached with 1 from another direction entirely. The fuseki calls for White 2 and Black 3. This is quite different, but once again the thickness in the lower left has become the focus of play.

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Example 32 How to Turn a Wall into Large-scale Territory

Black's territory is about 17 points.

This is White's sphere of influence

131

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White's territory is about 20 points.

This move, extending as far as possible, is imperative.

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Dia. 1. White 1 to 3 is a standard corner joseki, but such wanton neglect of White's thickness on the lower left is tragic. Black erases cautiously with 4, which is a big move. The value of White's thickness has gone into sharp decline.

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Dia. 2. This is the continuation of the correct answer. White plays contact at 1 in the lower right corner and Black cuts at 2 to cramp White's style. This strategy makes sense, as this area has already become settled territory for White. Black 2 defends against the push through by White 'a'. Black can also play V to force the response of White V; constraints have been placed on the expansion of white territory and influence. These are Black's countermeasures.

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Example 33 Clear-cut Spheres of Influence and Settled Territory Black to play.

This is almost territory.

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This is almost 30 points of real territory.

This area is Black's sphere of influence and a little difficult for White to enter.

136

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Dia. 1. The one-point jump of Black 1 is a thick move. There are many instances when a one-point jump towards the center from a stone on the third line is a good move. In addition to boxing in the territory in the upper portion, the sphere of influence on the lower side is enlarged. Moreover, if Black can next occupy the point of 2, his large moyo will assume such gigantic proportions that White cannot afford to ignore this point.

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Dia. 2. Black could also play at 1 first Now the cap at White 2 is the only move. Black 1 stops White enlarging his upper side while White 2 interferes with Black's large moyo. Here we have mutual reduction of moyos. Both 1 and 2 are good points and can be treated as miai.

138

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Example 34 The Perfect Solid Connection and the 'Thousand-Dollar' Bend First, Black has to tidy up

It is bad to omit this move.

All About Thickness

This is called the 'thousand dollar' bend!

139

Next if s White to play. The bend of White 2 is a thick move.

In this fuseki, the players are locked together in combat

140

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Dia. 1. The solid connection of Black 1 is a good example of a thick move. If, instead of the bend at 'a', White plays elsewhere and chooses a move like 2 on the left side, Black can then play the small knighf s move at 3, a brilliant large-scale move. In the rivalry between the two moyos, Black is definitely superior.

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Dia. 2. Going back to the start, if Black doesn't play the proper solid connection at 'a' and chooses instead Black 1 on the left side, in reckless disregard of his own safety, White can push through with 2 and 4, putting Black in a right fix. If he defends the two cutting points at 'a' and V, the two corner stones are going to find things very tough indeed.

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Example 35 The Early Bird Catches the Worm If s White's move. How should

This is an urgent point The side to play here first will gain the advantage.

All About Thickness

*2 up, 3 across' in combination with the pincer.

143

This is the ideal spot

144

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Dia. 1. White's marked stone occupies an ideal spot, as it combines both the balance of a 'two up, three across' extension with an attack on the marked black stone. After White has played his marked stone, Black will find it difficult to come to the aid of the single stone right away. The best move for Black is the shoulder-hit of 1, but the timing is tricky.

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Dia. 2. There is also the pincer of White 1, but the balance with the two white stones on the right is poor. Black is likely to invade at 'a', and it becomes difficult to say which has the stronger position. White 1 is too close to Black's strength on the left side, while the gap separating it from the two white stones to the right is too wide.

146

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Example 36 Don't Get Too Close to Thickness How should White play next? Using the principle 'the enemy's vital point is my vital poinf , consider the

The focus is around here.

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White 1 is the appropriate move. Black 2 is to be expected; White 3 on set limits on Black's area.

This is a critical mpve.

148

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Dia. 1. White could also try one line further at 1. This is the large large knighf s move. If next Black 'a', White counters with 'b' and vice versaso White has nothing to worry about White 'c', on the other hand, comes too close to the black thickness. Black can play 'd', after which White has to survive in the face of Black's wall. This will be no easy task.

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Dia. 2. Confining this discussion to the left side, if Black were to play first, Black 'a', White V , Black 'c' would be right and proper. At this stage, it is difficult to quantify the territories, but suffice it to say that Black can make a large territory and at the same time prepare a reception should his opponent decide to invade.

150

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Example 37 4HMMMMMWMMHNM6MMHMMNHHM

Playing at the Boundary of Influence The sphere of influence of the white thickness.

Black to play Whiter thickness

The right point for Black is around here.

All About Thickness

Black 1 is a calm move. White is satisfied with this compromise.

Although a little restrained, this is a fine move.

151

152

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Dia. 1. Black 1 is the very best spot. Against this, there is no way that White can reply at 'a'. If he chooses to invade with White 2, Black jumps out with 3, which also reduces White's thickness. Even after White 4, Black's two stones aren't weak at all, as Black can extend as far as V .

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Dia. 2. The lower move Black 1 is dubious, however. White will cap with 2, and this move, in combination with the thickness above, will establish White's domination of the center of the board. Black 1 at 'a' is a little too close to the thickness. If pincered by White V, Black's position will become quite painful.

154

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Example 38 Play in the Corner and Build a Large Moyo Black to play How do you plan your fuseki to take full

The focus of attention is around here.

155

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Black's forcing sequence from 1 to 11 quickly results in a strong wall.

This area is an almost certain 30 points for Black.

This extension binds the moyo together.

156

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Dia. 1. Black could play 1 and 3 with the idea of staking out the right side, but, because this joseki is too far away, it fails to make proper use of the thickness of the three marked black stones. White can now get a base in the corner with 4 and 6. Black 7 is a good point, but Black's strength lacks something in grandeur and vigorousness.

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157

Dia. 2. In playing the commonplace extension to 1, Black demonstrates a complete lack of grasp in his overall game. White 2 immediately takes the spot vital to both players. He has managed to defend against pressure from Black 2 and settle his corner. The scale of Black's strength is much reduced and there is no way he can use his thickness to build a large moyo.

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Example 39 The Point Which Connects in Three Directions Can't Be Bad White profit

Black to play

White profit

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The sanren-sei is ideal. The sanren-sei strengthens these connections. It is difficult for White to push into the center from here.

160

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Dia. 1. If Black plays 1, one line lower, he can be capped by White 2. Just one line difference has a dramatic effect on the whole game. White 2 breaks the lines of black influence radiating out into the center and it is difficult to see how an effective attack can be mounted against this move.

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161

Dia. 2. Black could have played 1 with the idea of enlarging the central moyo. This is a non-urgent point and in the wrong direction entirely. White will play elsewhere, with the midway point of 2 presenting itself. The distance across the center is too wide and the overall thickness becomes illdefined.

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162

Example 40 Imperfect Thickness Can Be Erased Completely White to play Should the erasure be deep or shallow?

Use this stone indirectly.

163

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The deep invasion will erase Black's thickness.

164

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Dia. 1. If Black caps White 1 at 2, White activates his marked stone with 3. Black plays 4 to prevent White pulling the stone out, White plays 5 and 7, finally descending to 9, and is almost certainly alive. If White can wreak destruction while securing life for himself, his game becomes the more promising.

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Dia. 2. For a shallow erasure, White 1 is normal, but while Black turns the upper side into settled territory with 2, White's two stones 1 and 3 are not yet stable. This insecurity will present problems to White. It is much safer to go the whole hog, make a deep invasion and commit oneself to securing life, as in the correct answer.

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Example 41 Thickness as the Basis of Large Moyos

Here's an ideal chance to build a large moyo from thickness.

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The moyo has grown to this extent

This is the way to build a large moyo based on thickness.

168

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Dia. 1. After Black 1 has enlarged the moyo, if White attempts to erase it from above with 2, Black can fight back with 3. Black exchanges 5 for White 6 to create some useful aji. Against the push of Black 7, White answers with 8 and by Black 13, both have enclosures with Black satisfied by his result. This development occurred in an actual game, with the whole of the right side unified into one large black moyo.

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Dia. 2. For Black to play 1 and 3 to aid the marked stone is a terrible strategic error. White jumps out with 2 and 4 and Black's all-important thickness simply withers away. The invasion at 'a' now appears possible and with no undue effort White has gained the upper hand.

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170

Example 42 Eliminate the Cutting Point Black to play

White has just connected here.

Where is the move

This is uncharted territory.

171

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White may not be able to enter this area of thickness.

White 2 is also a thick and proper move.

The order of Black 1 and 3 is important

Almost 50 points of settled territory.

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Dia. 1. After Black's solid connection at 1, White might well think of capping at 2 to erase the moyo. However this gives Black the chance to activate his single stone in the lower left, with 3 and 5, leaving White at a loss. White V in the previous diagram should have been played and indeed must be played. From Black's point of view, Black 1 looks to both possibilities.

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173

Dia. 2. If Black first jumps out to 1, White can cut at 2, bisecting Black. The attendant shortage of liberties rapidly makes Black's position untenable. Territory can on occasion be made naturally by playing thick moves, and if, when required to defend, a defensive move can be used which is also a thick move, this is doubly valuable.

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174

Example 43 Cover the Center With Thickness Backed by thickness, Black plays the shoulder-hit of 1 against White's 3-3 stone After Black 7, White will find erasure quite difficult.

is about 20 points.

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White's moyo has grown.

Once the central thickness is reduced, White can aim at reactivating this stone.

176

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Dia. 1. How about playing the shoulder-hit of Black 1 to prevent White from enlarging his position on the upper side? It is shrewd for White to ignore Black 5 and build a new position at 6. You can't expect White to reply with 6 at 'a' or such like. In this result, Black hasn't used his stones in the center well at all.

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177

Dia. 2. Against the correct shoulder-hit Black 1, it makes little difference whether White pushes with 2 in this direction. By 7, Black enjoys the same degree of success as in the answer diagram on p. 175. Black has made a majestic structure in the center simply by restricting the movement of the marked white stone from afar.

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178

Example 44 The Capping Move and Thickness Make Good Partners Black to play

The marked group of white

of black influence.

All About Thickness

The field of influence has grown.

179

180

All About Thickness

Dw. 2. Black 1 snuffs out White's light in the center and is the key move on the entire board. It is very difficult for White to find an effective answer to Black 1. If White plays 2 and 4 to strengthen the right side before tackling the upper side, Black will play 5 and 7 in order to settle matters for the whole board.

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Dia. 2. Black 1 is also a good point, but White will jump out at 2 without hesitation. As you can see, White 2 drastically reduces Black's thickness on the lower left This move also stabilizes White's large group. The outcome of the whole game is now unclear.

182

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Example 45 qmWttMmMttBMBMWBBMBBMlWlHBOiWia

Widen Your Horizons White to play

This move encloses the moyo, \,Qt more 8 e e m 8 ca iied for.

some finishing touches.

All About Thickness

White is ahead in territory by the size of this area, about 5 points.

183

A large territorial moyo has been made possible Use this stone

184

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Dia. 1. White 1 is a most conventional way of constructing the moyo but too honest for its own good. This move doesn't take full advantage of the situation, so Black plays 2, By White 7, the game has become extremely close. White 1 at 'a' is too small in scale and can be dismissed as irrelevant.

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185

Dia. 2. White might consider 1 to forestall Black's hane at the head of two stones, but this is from the wrong direction. Black caps at 2 and immediately White's moyo is reduced. If steps aren't taken to consolidate thickness into a territorial moyo, the territory can easily be lost and become insufficient.

186

'Thickness' in the Go Proverbs

'Thickness' in Go Proverbs

The shoulder-hit and the capping move for shallow erasure These methods are effective for reducing both moyos and thickness when a deep entry is impossible. You can't win on thickness alone If, finally, thickness doesn't turn into territory, you'll lose. Don't make territory from thickness While thickness is very useful for fighting, it is inefficient when it comes to enclosing territory in the center. Don't approach thickness Get too close to it and thickness will provide the backing for the most savage attack. You can't win by capturing stones If you concentrate on capturing stones, oblivious to all else, the opponent can employ sacrifice strategy to make thickness. Avoid getting tied in a knot If you don't want to be presented with an impenetrable wall or thickness, don't allow yourself to be tied in a knot by throw-ins or sacrifice stones. The one-point jump is never bad As in Dia. A, one-space jumps breaking out into the center are rarely bad.

All About Thickness

Dia. A

187

Dia. B

Make a large sacrifice to seal off an area Play forcefully from outside to sacrifice stones, create overconcentration in the opponent and make thickness for yourself. Erase large moyos with the capping move and the shoulder-hit This has the same importance as the proverb 'The shoulder-hit and the capping move for shallow erasure'. The tortoise-shell is worth 60 points The strength of the thickness of the tortoise-shell shown in Dia. B can be compared to 60 points of territory. Divide and conquer When trying to split up positions into two or more portions, the presence of thickness has a profound effect. A single cut may be the key to success A single cut may help you to rescue your own groups or cause your opponents thickness to crumble.

188

Thickness' in the Go Proverbs Pushing the cart from behind is an example of bad go The more you push, the more territory you give the opponent. As in Dia. C, pushing helps the opponent to split you into two while making himself thick.

Dia. C

Attack is the best form of defense Attack positively; while the enemy struggles to survive, you build thickness. Don't push along the 5th line Thickness may be made by pushing along the fifth line, but the result will be inferior to the opponent's territory. A gote move may be sente later Although gote, a thick defensive move, strengthening weaknesses, can hold promise of severe maneuvers later. Crawling along the 3rd line is joseki Territory made by crawling along the third line will balance the thickness gained by the opponent. 3 up, 4 across When three stones joined vertically rise away from the edge, an extension of four spaces is possible. Each stone added to a ladder loses 7 points For every stone added to a ladder that doesn't work, the

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loss, in terms of thickness granted the opponent, is said to be seven points. •

Let the opponent hane at the head of four stones, but not at the head of three Let the opponent hane at the head of four stones but not at the head of three. If you let him hane at the head of three stones in a row, he'll reduce your liberties, take the initiative and build thickness.

•

Learn to sacrifice and take a big step forward In Dia. D, by sacrificing one stone at 1, White is able to play 3 and 5 to amass thickness. Dia. D

•

Take territory while attacking If you can use thickness for attack, territory will appear quite naturally. • Attack is linked to defense This proverb is the same as "Attack is the best form of defense". Useful gains can be made by attacking. •

The enemy's vital point is your vital point Look for the point the opponent wants to play: it may also be the vital point for you.

•

In a symmetrical position, the side to play first takes the advantage When equivalent thicknesses or strengths oppose each other, there is usually a vital point midway between them that you want to seize before the opponent.

190

'Thickness' in the Go Proverbs Don't enclose the center Thickness may be made in the center, but it is inefficient to try and use this thickness to enclose territory. Learn the two-step hane and you're nearly shodan The method of play which follows one hane with another to build influence is strong and severe and almost never used by a weak player. The second line is the losing line Crawling along the second line may produce some territory, but the thickness gained by the opponent is far greater. Add a second stone and sacrifice When a second stone is added before a sacrifice, the enemy has to use many more moves, which allows you to build a profitable wall or thickness. Play hane at the head of two stones Hane can be played at the head of two stones in a row, almost without thinking. This builds up your influence. Two up, three across As seen in Dia. E, White 1 can extend three spaces from his two-stone wall.

Dia.E

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All About Thickness •

When you can't pincer, play contact In the case of strong stones which cannot be pincered, play contact moves and lean on them to become thicker.

•

Use the whole of the go board Don't fuss around with small bits of territory: realize your dreams by building magnificent moyos.

•

Poor open-connection, good solid connection The duffer makes open connections, the expert solid connections. In many cases the solid connection will enable you to play strongly in struggles for influence.

•

The star-point always has the 3-3 invasion The star-point is weak on territory, but in compensation making thickness is relatively easy.

•

Ponnuki is worth 30 points Even though the actual point count doesn't amount to much, the power of the shape left by the capture of a single stone, as in Dia. F, when turned into thickness is equivalent to 30 points.

Dia. F

•

The bend-contact is priceless Bending round in contact to block the enemy's route also occupies a key point vital to the development of both players' influence.

•

Cap in the heart of the moyo The move which can obstruct an expanding moyo is the capping move.

192

'Thickness' in the Go Proverbs Never cede to the opponent the key point for building both moyos In moyo contests, there's often a crucial point for expanding both moyos. Leant on in two directions, the game is lost If you come under pressure from two directions at once, the opponent's thickness will become very strong.

All A b o u t Thickness

193

Index: Types of Thickness Thickness in the Opening Arrangements of stones which lead to thickness a. Handicap go 2-stones, 6-stones, 9-stones (Ex. 1, p. 2; Ex. 2 p. 6) b. Niren-sei c. Sanren-sei (Ex. 28, p. 112; Ex. 39, p. 158) d. Miscellaneous (Ex. 21, p. 84)

Josekis to produce thickness (Ex. 3, p. 10; Ex. 4, p. 14; Ex. 5, p. 18; Ex. 6, p. 22; Ex. 7, p. 26; Ex. 8, p. 30; Ex. 9, p. 34; Ex. 10, p. 38; Ex. 11, p. 42, Ex. 14, p. 54; Ex. 22, p. 88; Ex. 23, p. 92; Ex. 25, p. 100)

Thick moves e. Jump (Ex. 24, p. 96; Ex. 33, p. 134) f. Bend (Ex. 34, p. 138) g. Push (Ex. 1, p. 2; Ex. 2, p. 6; Ex. 6, p. 22) h. Press-down (Ex. 7, p. 26; Ex. 38, p. 154) i. Connect (Ex. 20, p. 80; Ex. 34, p. 138; Ex. 42, p. 170)

Thickness in the middlegame Utilization of Thickness j . Expansion of thickness (Ex. 33, p. 134; Ex. 41, p. 166; Ex. 43, p. 174; Ex. 44, p. 178; Ex. 45. p. 182) k. Extending from thickness Striving for safety (Ex. 16, p. 64) Making territory (Ex. 18, p. 72; Ex. 26, p. 104; Ex. 27, p. 108; Ex. 32, p. 130; Ex. 39, p. 158) Attack combined with making territory (Ex. 12, p. 46; Ex. 13, p. 50; Ex. 15, p. 60; Ex. 17, p. 68; Ex. 19, p. 76; Ex. 35, p. 142)

Index: Types of Thickness

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Reduction of thickness 1. Light erasure of thickness and escape (Ex. 29, p. 116; Ex. 36, p. 146; Ex. 37, p. 150) m. Deep erasure, taking the fight to the thickness (Ex. 40, p. 162)

Thickness in actual play One move that can make the difference between thickness and territory (Ex. 30, p. 122; Ex. 31, p. 126)