Chapter Six. Blocking Off

6.1 Open skirts and crawling plays

Plays on the fourth line are much used in modern go, despite the open skirt they leave on the second line. They emphasise influence over territory. Proper shape to block off is essential, since attacking play alone isn’t enough.

White has slid under a fourth line play. How should the game continue?

Black normally plays back with a diagonal at 1. Then the onus is on White to make good shape. The ‘odd diagonal’ at 4 is appropriate, once Black has answered 2 with 3. It looks to make good eye shape at 5. If Black denies White the chance as shown, White 6 and 8 ensure White reasonable shape.

It is a novice’s mistake to jump in at 2 in this sort of position. The territory on the edge is less important than eye shape, until the endgame. Black 5 is strong, and White is left with a weakness at A.

Another mistake is to take violent action with Black 1, to shut off the edge. White will normally be quite happy to sacrifice on the right, to gain a ponnuki and safety for a group on the left inside Black’s former framework.

If the situation demands it, Black can block White’s progress on the second line. As shown here, Black has little chance of attacking White’s group, which has strengthened itself by plays on the right. It therefore makes sense to treat the marked stone lightly with 1 and 3. Black is content with securing the left-hand corner, in sente.

6.2 Moles and submarines

{{Dia 330} {{Dia 331}}

Unsupported plays on the second line, such as White 1, A, B or C in the lefthand diagram, have been called ‘submarine plays’ in English. They range from trick plays to proper invasion techniques. The Japanese say ‘mole’ or ‘hem’ plays, the latter for plays like Black 1 on the edge of the skirt (right).

(Left) Playing from above builds strong shape, and keeps Black low. (Right) Running back with a knight’s move constructs influence, but costs territory.

The diagonal play (left) can lead to sharp tactics. Black could escape with 10 at 15, having only a false eye from capturing White 1; Black 10 here is a novel idea. Note the play 7, reaching further than a solid connection would. (Right) Confrontation with White 1 relies on 2 being a failure. When White 3 is a good idea Black presumably plays 2 at 4 immediately. (Cf. 4.9.)

With this other play aiming at the open skirt of a 4-4 point, Black has room for a comfortable life in the corner (left). White will usually defend it (right).

White can also play in contact. (Left) Black is close to life, next playing A or B. White has an option to play 3 at 4 in this line (cf.15.1). (Right) White tries to make Black heavy with the diagonal attachment at 1. Black’s proper move here is to play 2 at 3; taking the outside risks a heavy group. After 5 Black chooses between A, B and C. Atari at D is to be avoided, for the sake of possibilities in the corner.

It is rare for the approach 1 in this diagram to be good; but in this context it seems to be right. After Black 1, Black at A in the corner would be efficient, so White 2 blocks the way. But then Black 3 combines attack and defence perfectly, putting the marked White stone’s safety in question.

6.3 Half-blocking plays

Threats to block off are an important class of practical plays. They often count as almost sente: having a major follow-up. In the position shown on the left, White 1 aims firstly at A, and then when Black responds at 2, leaves some residual possibilities at B. (Right) This Black 1 is a mistake.

Sometimes the diagonal White 1 (left) gains more influence than the simple bend, one point to the left. But in this case White gives up most of the chances of a later play at A. The follow-up at 1 (right) would have to combine with other stones near the ‘x’ points, to justify this choice.

The knight’s move White 1 here can be thought of as a central strategy. Black probably slides to 2 (left). Cutting (right) should turn out to be an overplay, since after 4, 6 and 8 Black has to take good care of the corner.

6.4 Using the fourth line

This sequence has occurred often in professional play. What is the meaning of White 3? The normal idea here is to play at A, to secure a definite base for the White group; and this is also common.

The idea is to jump at 2 in answer to Black 1. Then White at A is a halfblocking play, which Black will almost certainly answer at B. That exchange would do much to neutralise the influence of the marked Black stone. Black normally defends the left side, and White takes the initiative. In any case, White isn’t here so concerned about points on the lower edge.

The logic of playing on the fourth line includes the use of the footsweep of 5.4, like Black 1 here, to seal the edge, before playing for a framework with 1. As soon as White invades at A, the difference will be noticeable.

White plays 1 to live inside Black’s framework. After White 3 Black extends to 4 for good shape, but this loses an opportunity. White 5 calmly devalues Black’s position, though a chance for Black to play at A remains.

Black could have played the footsweep 1 here. If White resists with 2, Black 3 puts White in trouble. There are tactical chances for White at A and B; but White can’t expect a good result with such weak stones appearing at an early stage of the game.

A story about the previous position, from the 1997 match Macfadyen-Matthews. Matthews had seen White 1 in a game Macfadyen-Janssen, commended by Miyamoto Naoki 9 dan. This variation is given by him as good for White (so Black’s immediate invasion 4 isn’t sensible). Noting novel shape ideas is one way to prepare against strong players.

Problem Set 1. Creating Good Shape

Both problems Black to play at A or B

Answer B is correct. Black should simply extend the three-stone chain. Then the strongest play available to White is hane at 2, an endgame play worth about 13 points.

{{Dia 357}} {{Dia 358}} If Black jumps into the corner (answer A) White 2 is in the hane-at-thehead-of-three-stones position relative to the marked stones. White can capture the corner with 4, threatening 5.

Black should play the hanging connection (answer B). Then Black has a chance to play the cut on the outside at 5, before worrying about the safety of the group.

Descending (answer A) is bad shape. If White attacks immediately Black only just survives and White gains influence (left). Black’s plan of giving up two stones (right) is bad, since the cutting points ‘x’ disappear.

Both problems Black to play at A or B

Black should jump to 1 (answer A). This is an example of light shape. If White cuts at 2, independently of any ladder Black can give up one stone and squeeze with 3 and so on.

Answer B, the hanging connection, is a heavy shape. White can play 2, and then wait for a chance to cut with C, Black D, White E.

Here again the right answer is B, the one-point jump. Black should play lightly, aiming at the point C, and not worrying about 2 and 4. The weak point left at D isn’t so serious.

Extending (answer A) is heavy shape. It is easy for White to jump ahead of Black in the running fight.

Both problems Black to play at A or B

Black should make the table shape (answer B). This is good shape. In this position Black should think first about moving out into the centre. (Right) This result would be good for Black (8 connects).

Black A leaves an incomplete shape. (Left) White 2 is obvious and best. (Right) Then 3 is the proper play for Black, but naturally this isn’t very good shape.

Correct in this case is the knight’s move press (answer A). Black moves out quickly, and can soon attack the marked white stones.

{{Dia 379}} {{Dia 380}} In this case the table shape A is slow. White jumps ahead of Black and takes territory.

Both problems Black to play at A or B

Black should play the diagonal move (answer B). This defends territory. If White spends time taking two black stones with 2 and 4, Black takes profit elsewhere.

The table shape (answer A) is a poor move here. Black’s shape is inefficient. White can exchange 2 for 3 and be content.

In this problem the table shape (answer A) is best. It prepares for the rescue of the isolated black stone shown in the right-hand diagram.

Jumping to B is a loose shape in this case. White pushes up at 2 and then plays 4: Black is in trouble. Therefore Black 3 is bad, though on a bulge point. Since the marked cutting stone also now looks like being swallowed up, it seems that Black has chosen the wrong direction to emphasise.

Both problems Black to play at A or B

The contact play (answer B) is the way for Black to make good shape here. In the continuation shown Black is out into the centre, and White has a cutting point to handle.

Simply jumping out (answer A) is slow. Black runs out into the centre but is subject to further sustained attack.

The contact play (answer B) is again correct here (the contact play on the other side of the same stone is also good). White 2 (right) isn’t a problem as Black comes out into the centre with good shape.

If Black answers at A, it is easy for White to find further attacking plays.

Both problems Black to play at A or B

Black does better here with the cross-cut (answer A). By giving up one stone Black can secure some shape on the left and then play 7.

The problem with answer B, the bulge here, is that Black finishes with rigid shape. No longer does Black have the options to answer 2 at C or D. White also has the option to connect at 5 with 4, for central strength.

Correct is answer B, the contact play under White’s enclosure. With the result shown White’s two marked stones have become a target for attack.

Simply connecting (answer A) is heavy and shapeless. When White plays 2 Black is in for a difficult fight.

Both problems Black to play at A or B

Correct is answer B, blocking White’s direct path out into the centre. Black has nothing to fear in the right-hand diagram, or if White 2 is played one to the left.

Simply extending back is slack shape. At some later point White may be able to cut Black in good shape, with the knight’s move 2.

In this case Black should extend (answer A). This secures for the time being the group on the left side. If something like the right-hand diagram occurs Black has settled on both sides.

To play hane here is to court immediate disaster. With 2 White threatens a snapback to capture the cutting stones. The result to 6 is very bad for Black.

Both problems Black to play at A or B

Answer B, with a sacrificial intention, is correct here from the point of view of shape. In the right-hand diagram White is already in bad shape.

Simply extending (left) is less efficient. Playing atari (right) is a novice’s mistake: there is no reason for White to save the two marked stones.

In this case the jump to A lands on the key point of White’s enclosure. If White immediately tries to cut Black (right), Black will be happy with an exchange.

The shoulderhit Black 1 in this diagram isn’t so good. White takes the key point 2. (Right) Once Black has made shape as shown, Black 1 patches up.

Both problems Black to play at A or B

Here the shoulderhit A is best for Black. It is natural for White to push with 2; but then Black develops good shape with 3. Black is now comfortable answering White C with Black D.

The one-point jump is here loose shape. With 2 White can leave Black an eyeless and heavy floating group. The sharp play 4 is even possible.

Answer B is the key point of this shape. As the right-hand diagram shows, it would also be the best place for White to occupy to attack it.

Here the shoulderhit Black 1 isn’t a good idea. Simply by pushing up White can make Black’s shape look redundant: the three marked stones are too close together.

Both problems Black to play at A or B

The bulge play B is good shape here. By sacrificing one stone Black can break out of confinement, and at the same time make the marked white stones into a weak group.

If Black descends to A to stop White’s connection along the edge, the wedge White 2 causes immediate trouble. Black cannot defend both C and D.

Black should immediately play A. If White plays 2 Black can answer at 3 and 5. Since the marked Black stones aren’t very important, Black has good shape: White has no good way to combine the cuts C and D.

Descending at B is short-sighted. White 2 can cause trouble now or in the future, at E or F.

Part Three. Practical Fighting

Chapter Six. Blocking Off#

6.1 Open skirts and crawling plays#

6.2 Moles and submarines#

6.3 Half-blocking plays#

6.4 Using the fourth line#

Problem Set 1. Creating Good Shape#

Both problems Black to play at A or B#

Both problems Black to play at A or B#

Both problems Black to play at A or B#

Both problems Black to play at A or B#

Both problems Black to play at A or B#

Both problems Black to play at A or B#

Both problems Black to play at A or B#

Both problems Black to play at A or B#

Both problems Black to play at A or B#

Both problems Black to play at A or B#

Part Three. Practical Fighting#

Chapter Six. Blocking Off

6.1 Open skirts and crawling plays

6.2 Moles and submarines

6.3 Half-blocking plays

6.4 Using the fourth line

Problem Set 1. Creating Good Shape

Both problems Black to play at A or B

Both problems Black to play at A or B

Both problems Black to play at A or B

Both problems Black to play at A or B

Both problems Black to play at A or B

Both problems Black to play at A or B

Both problems Black to play at A or B

Both problems Black to play at A or B

Both problems Black to play at A or B

Both problems Black to play at A or B

Part Three. Practical Fighting