2. Ignoring a Forcing Move
The Wedge-in Tesuji

by Richard Bozulich

In the struggle to seize the initiative, especially in the opening and early middle game, the opponent will often make moves that you might feel compelled to defend against. Such moves are known as forcing moves. If such a move is truly forcing — that is, if you will suffer a significant loss by ignoring it — then you may not have much of a choice but to defend against it.

However, if the obvious way of defending against a forcing move results in an inferior position, you should look for alternative ways of responding.

Here is an example from a recent professional game.

White to play
Highlight Diagram. White to play
Black needs to secure his stones at the top, but he also wants to attack the white stones on the top right.

He starts his attack by peeping with the marked stone, threatening to cut at 'a'. How should White defend against this peep?

Figure 1 (1–43)
Figure 1 (1–43)
Here are the moves that led up to the position in the highlight diagram. They were played in the 32nd Ryusei tournament between Akiyama Jiro 9-dan (Black) and Mizokami Tomochika 9-dan on April 27, 2023.

Dia. 1
Dia. 1. An eyeless string of stones
Connecting with White 1 is out of the question. White is left with bad shape (two empty triangles). Moreover, his group is an eyeless string of stones and makes a juicy target to attack. White also ends in gote, so Black can immediately start his attack with 2. This move also secures Black's group at the top. Instead of 1, White could also answer at 'a' or 'b', but the result would not be much different; the point at 1 would be a false eye.
So how should White answer?

Dia. 2
Dia. 2. Living at the top
One possibility for White is to live at the top with 1 to 5. If Black now cuts at 'a', White turns at 'b', threatening Black's group in the corner. Moreover, Black's group in the center top is still not secure.

So how did White actually play?

Figure 2 (44–51)
Figure 2 (44–51)
White answered Black's peep in the highlight diagram by turning at 44. Black's corner is in danger, so he is forced to defend with 45.
Next, White wedges in (hanekomi) with 46. This is a sharp tesuji. After Black 49, White cuts with 50 and Black must make shape with 51. The curious point about this position is that White is unable to cut at 'a'.

Dia. 3
Dia. 3. The Crane's Nest
Suppose Black does cut at 1. White ataries with 2, then wedges in with 4 (a warikomi). This is the famous 'crane's nest' position. The four black stones above 4 are captured!

Dia. 4
Dia. 4. Connect and die
If Black tries to escape with 5 and 7, White ataries with 6 and 8. Suddenly, Black finds his stones short of liberties. If Black connects at the marked stone, White captures at 'a'. This technique is known as oi-otoshi in Japanese, literary 'chase and bring down', but usually translated into English as 'connect and die'.

Dia. 5
Dia. 5. The wedge-in tesuji
Instead of directly cutting with 1 in Dia. 3, Black might first atari with 1, then cut with 3. Black avoids the crane's nest, but he has another problem — the wedge-in (warikomi) tesuji of White 4.

Black tries to escape with 5 and 7, but White ataries with 8. Next —

Dia. 6
Dia. 6. Caught in a ladder
Black must connect at 9, but White now ataries with 10, so the black stones are captured in a ladder.

Figure 3 (52–58)
Figure 3 (52–58)
The game continued with White 52.
Black 55 revives the possibility of Black cutting at 'a', as this move renders Dias. 3 to 6 invalid. However —

Dia. 7
Dia. 7. A vast moyo
Suppose Black cuts at 1. White could then atari with 2, then atari again with 4. Black has no choice but to capture with 5, but White ataries again with 6, forcing Black to connect at 7 (at the marked stone).

White has sacrificed his five stones at the top, but in return he has staked out a vast moyo at the bottom. This more than compensates for the five stones White has lost at the top.

Figure 4 (59–62)
Figure 4 (59–62)
In the game Black ataried with 59 and White connected at 60, forcing Black to capture the key stone with 61. The issue of the cut was now resolved; White ended in sente and played at 62.

Figure 4 (63–100)
Figure 4 (63–100)
Here is how the game continued.

Figure 6 (101–221)
Figure 6 (101–221)

221 moves.
Black won by resignation.