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Chapter Eight. Attach-Extend Mysteries

8.1 The common cutting points

This attach-extend pattern is played by Black to become solid, and move across the gain line. But in fact it leaves a number of cutting points (A for White, D after White B, Black C, and E for Black).

Trick plays (White’s cutting point matters greatly). (Left) A ko fight, and Black has a threat at A. (Right) After Black 14, White is in trouble here.

Bluntly pushing along (left) is usually bad for Black (unless White suffers hane-related bad shape from a Black stone at an ‘x’ point). (Right) The more subtle and normally better diagonal play 1 here threatens to cut at 3.

(Left) A tactical trick for White in this shape. (Right) When White has the extension with the marked stone in place, White should play 2 rather than 3 when cut at 1 to avoid overconcentration, and give Black bad shape. White now has forcing plays at A or B.

If White pushes up into the centre, Black must play 2 as a point of pride. Now White cuts with 3, and Black defends in good shape with 4. (Left) White 9 is a possible idea, aiming at A and B. (Right) White 5 sets up a ko lock tactic (5.6), but Black avoids it. Black now must attack forcefully on the top side, since White has made fine shape on the left.

8.2 The double approach

Black 2 in response to White’s second approach at 1 is a venerable opening. Black 6 is quite safe, since White 1 is on the third line. In most cases the cutting sequence (right) is a loss for White.

(Left) The standard sequence, with a number of plays that could easily be missed; for example Black 10 in answer to Black 9 avoids a possible cut. The meaning of 16 is that it prevents the clamp attack (right).

(Left) White should not play atari (marked stone), or the clamp fails: Black 4 prevents White A. (Right) Black may play 1 instead to cover the weak point in the corner. White at 2, therefore, allows Black to take sente. It is perhaps hard to call White 2 a mistake, in isolation from the rest of the board.

8.3 The high pincer attack

Black 1 here is a fundamental attacking shape, when for some reason White neglects to extend along the top side. White has to decide whether life on the side or running out is more important. Any of A to E in reply may be suitable on occasion.

Most usual is to run out with 2 and 4 in the left-hand diagram. This requires some explanation, though. (Right) It can be found in the peep, played in line with 7.7. White’s resource of 2 and 4, to take sente, is the reason White submits to making an empty triangle. Here is another case for pushing into a knight’s move (7.6). In fact Black ought to play 3 at 4, to resist.

Response B implies White will have to react passively to 5 here, since the same idea (right) runs into bad shape with 10 and a desperate ko fight.

Amongst ways to seek life, White C is easy to understand (left). White makes space for eyes, while leaving Black some cutting points. (Right) Another option is double hane with 6 here, emerging into the centre.

White D looks to cross-cut and then live on the edge. Since Black 7 at A is a tactical failure, and 7 at B leads Black into poor, rather heavy shape after White A, this is a reasonable tactic; Black 7 should calmly extend as shown, and leave the decisions to White.

Sliding all the way to E is perhaps the simplest way for White to play. It anticipates Black 3 and 5, cutting off one stone. White has conceded central influence to Black, but the points A and B are now useful ways for White to attack Black’s shape. This final way of playing comes closest to the idea of calculated risk, to be introduced at the start of Chapter 12. White should in any case think twice before allowing Black to attack in this fashion.

8.4 The high pincer as good shape

{{Dia 537}} {{Dia 538}} The high pincer is versatile, turning up in other openings. Black 2 here allows Black 4 and 6, which leave it perfectly placed. (Right) This variation is recent research; Black will continue at A or B.

When White 7 invades the corner instead, after Black 10 the pincer is on a ‘centre of three stones’ point (4.6), as the right-hand diagram reveals.

8.5 The low pincer attack

Black could also play 1 on the third line, perhaps when somewhat stronger locally. (Right) The standard way. Black could now peep at A or B, but seems to need a play at C quite urgently.

White shouldn’t fall into the trap of playing 2 this way. Black’s wedge at 3 is strong here. (Right) White 4 played this way means Black cuts at A or B.

Therefore White 4 must be on the other side, leading to complexities. (Left) After 15 Black has a ladder (A) or net and squeeze (B). (Right) In this other variation White cannot reasonably break out.

Doesn’t work: White is simply creating more and more influence for Black. The low pincer is more severe on White, but is worse shape and potentially an overplay, since the pincer stone may be subject to counter-attack. These tactical variations are possibly misleading, therefore. In professional play either of the pincers may be employed, depending on the requirements of the whole board position.

Chapter Eight. Attach-Extend Mysteries#

8.1 The common cutting points#

8.2 The double approach#

8.3 The high pincer attack#

8.4 The high pincer as good shape#

8.5 The low pincer attack#