The original meaning of this stratagem is: on the surface we appear peaceable, letting the opponent believe in us, and furthermore making him numb to the main idea. But we secretly prepare a dagger, waiting for the right moment to act, so the opponent has no time to react.
The application to Go is: It looks as if we are playing aimless, ineffective moves, but actually it is a secret operation. When the opponent becomes confused by the false front or relaxes his vigilance, then we suddenly make our move, leaving him helpless.
Basic Figure: Taken from a game in the Fifth “National Championship” of 1985. The exchange of White " for Black + was made long ago. Here Black's correct play is osae at a, settling the position. Because just the stump of this error has been left behind, White has a definite opportunity.
Under normal circumstances, Black would be in the lead. Black has about 55 points, White at least 45 points plus a little potential in the center, and it is White's turn to play. Although with steady play [White] would stay a little behind, in the final analysis the fight would be decided in the endgame. It all depends on what strategy White uses.
Diagram 1: Under normal circum-stances, White would exchange the biggest yose with Black at 1 and 2.
Then after hane in sente at 3, he would turn to some other yose point. But this manner of play is only for those positions where White is ahead or the game is close. In the current position he is behind so he should not play ac-cording to the normal approach, settling the position, because after it is settled the opponent can pre-cisely judge the size of his lead. In the diagram, with White 5 and
af-ter, he loses his options. After White 9 and 11, Black gains sente. He only needs to play the simple tsuke-oshi at 12 and 14 and then reinforcement at 18. Black obviously is better. Now the situation is as follows: Black has 43 points on the left side, a total of 14 points on the lower and right sides, six points in the upper right corner and two points on the upper side, for a grand total of 65 points. White has 25 points in the upper left corner, 15 points in the vicinity of the
right side, about 12 points in the center, a grand total of 52 points plus potential for development in the center.
On the board there is a difference of about 13 points, and no matter how the center is developed he cannot possi-bly make eight points or more, so White is lost.
Figure 1 - Actual Game Con-tinuation: Of course, White absolutely must make the yose plays on the upper side, so he should reserve any
variations and just play 1 and 3. This way, Black's calculations are bit more murky. The magari at Black 4 is the biggest yose play-its value is not small. But this move is Black's little, tiny mistake. Black should have considered playing on the right side. From White 7 to 15, the yose plays are quite ingenious. White gains a lot of profit on the side and in the center. At this point, the game has become close.
The tsuke at 16 down to the capture of four stones with 26 looks large, but actually the gain is insignificant. The profit from Black's capture of four stones is reduced by White's capture of one stone in the center, so the value is small. Therefore, we can recognize that Black 16 and thereafter are the final losing moves in this game.
Figure 2 - Actual Game Continuation: After White takes a little profit in sente at 27, splitting Black up at 29 is the best policy. Black 30 could only be played at 37 or 36 to reinforce that group. If that way, then White would play hane at 33 and a, then take the point on the left side at b, and the outcome of the game is hard to predict. He would have to watch each yose play carefully. In the figure, when Black played 30, White 31 was an alert and
resourceful move! After this, Black has lost the yose play at 40. The balance of victory was tipping in White's favor. The connection at Black 32 was a misconception. He thought he could make life here, but neglected White 35 and so forth taking away Black's eye space, as well as the sente kake-tsugi at 41. This is the legacy of the exchange of White "
and Black + in the Basic Diagram and it is also this mistake by Black that gave White the opportunity to win. Once White had played kake-tsugi at 41, Black could only make life for the big dragon in the middle of the board, and with the kosumi of 45 White unconditionally killed Black's
corner. (After White connects at 47, Black c, White d, Black e, White f.) So right here Black was finished.
Black had responded at + in the first place because he mistakenly thought about the variation in Diagram 2.
Diagram 2: Black overlooked the White kosumi at 45 in the actual game, thinking that the strongest move was White 1 here. After atari at Black 2, he is alive with 4. If White 1 is played at 4, then Black can calmly play ate at 3, and he is alive all the same.
The primary reason Black lost this game is that he did not notice that " would be sente. The other losing moves were 16 and 18 in Figure 1. At that time, Black was still in the
lead. He only needed to make accurate yose plays to gain the victory.
(When he played tsuke at 16, the correct yose sequence was more likely as in Diagram 3.)
Diagram 3: The largest move was the single-stone capture at 16.
After narabi at White 17, when White peeps at 19, the de-ate at 20 is well-timed. This is very hard for White to take. In order to protect his territory on the side, he must reluctantly part with these two stones. The tsugi of White 23, capturing one stone, is a big play. Black gains a little in sente at 24 and 26, then settles the position in sente with 28 to 33, and finally takes the big yose play at 34. Black is ahead of
White by almost 10 points on the board, and can force the win. Perhaps in the course of this yose, there are some better plays. For instance the exchange of the peep at 19 and Black 20 was a slight loss.
But with a lead of close to 10 points on the board, Black only needs accurate endgame play, and no matter what, the end result won't change.
At least we can end this by saying Black wins by a small margin.
Conclusion: Black + in the Basic Figure should have been played as osae at a. But Black did not play this way. So White judged that Black might not notice that White 41 in Figure 2 would be sente. Based on this judgement, he undertook a series of preparatory works, patiently waiting for Black to make a mistake. How can we make Black make a mistake?
Without a doubt we need to adopt several tactics on several fronts. In this game White adopted what seems a most ordinary playing style, to relax his opponent's state of alert. In Figure 1, White used 1 and 3 to start an ordinary yose. It was very far-sighted and circumspect. When Black wholeheartedly entered the endgame, focusing his attention on how to best profit from yose play, White again “calculated” the problem of the safety of the Black dragon. He waited until he was able to play the kake-tsugi at White 41 in Figure 2. Then Black was in the misfortunate position of not being able to save both groups, and therefore losing one of them.
This illustrates how White was able to turn the tables because of his artful utilization of the stratagem “hide a dagger with a smile”.