Validación de instrumentos por juicio de expertos

The stratagem “throw out a brick to attract jade” is a kind of plot used to lure the enemy. There are many ways to lure the enemy. The cleverest of these use realistic means to lure the enemy into a trap. Just from its words, we can explain this stratagem as: we throw out something that is not too good to draw out a good thing. Its meaning applied to Go is:

Make an ordinary, or what looks like an ordinary, move and then use this ordinary play to lead into a series of excellent plays.

Basic Figure: Taken from the Third China-Japan SuperGo Tournament.

Now the foci in this game are the left and right sides. The White camp on the right is wide open. It needs one more move to consolidate. On the other hand, the Black group on the left side is not yet settled, and White is relatively thin. This is a complicated position, so finding a good plan is more difficult.

The following analysis is presented for your edification.

Diagram 1: Playing a strengthening move on the right side with White 1 makes good shape. With this, the right side basically belongs to White. But although this move is very large, it is not the most urgent. With the keima at 2, Black commences an attack. White can only block at 3.

The Black oki at 4 is severe! With move 5 and thereafter, White can only let Black have his way. After Black captures one stone in sente, taking some profit, he plays keima at 12 and White's entire group

be-comes unsettled. We can't even talk about attacking Black. From the standpoint of the whole board, White has only one area of territory on the right side. It will not be easy for him to win.

Diagram 2: The correct approach is for White to play on the left side instead. Sagari at White 1 is the usual play. After Black jumps at 2 to make shape, it is relatively difficult to find a way to attack Black. White 3 and 5 are a strong attack. The play for both sides would probably continue as here from Black 6 onwards. Black builds up thickness in the center in sente, and is able to make the big play with the keima at 18. The yose from 22 to 26 are very large.

27 is double sente. After settling

things with 28 and the following kikashi, Black plays osae at 40. The game has become one that will be won or lost by contesting yose. Overall, the territory is about even, but Black's center is thick and has some potential for development, so the game favors Black slightly.

From the Basic Figure we can see that Black has a lot of territory, while White has a moyo on the right and is thin on the left. If he wants to open up the game, then White has to start on the left and move the battle line toward the right side, using a positive offense as his defense.

Figure 1 - Actual Game Continuation: This was just the right time to press at White 1. To keep White from getting too much use out of it, Black probably could only put up with hiki. Tsuke at White 3 was the key move for using the stratagem of “throw out a brick to attract jade”! It follows that Black 4 played right into White's hands. By peeping from the other side at 5, White forcefully destroyed Black's eye shape, forcing Black to suffer playing 6, 8, and 10 to simply link up his stones. White cut him off and continued the attack at 11. The cap at 13 was perfect. After White's kosumi at 15, taking a little profit, advancing and retreating, sooner or later he would withdraw his army and turn his effort to managing his territory. Capturing two stones at 16 was premature. White again played shinogi in sente and then grabbed the big point on the left at 23. Now Black found it was already difficult to reduce White's moyo on the right side, because from start to finish Black's central group has been unsettled and harassed. White clearly established superiority over the whole board.

Diagram 3: If Black changed his move 6 in Figure 1 to the atari here, then White would cut at 7.

When Black captures at 8, the osae of White 9 is a good, calm move. Now Black has to connect at 10, and White can play atari at 11. Although Black captured one stone, he does not have an eye. If White gets to take the ko at "

right away, it will be sente. In this ko, White is light and Black is heavy, not good for Black. The result is that Black helps White build thickness on the side, so Black is at a disadvantage.

Diagram 4: If White did not block at 9 in Diagram 3, but directly cap-tured a few stones with White 9 as here, then he would have lost sight of his goal. Maybe this is what Black was thinking about at the outset. The Black keima at 10 is severe!

Although White captures seven stones, his territory on the side has been destroyed and some of his stones have become isolated.

Clearly the loss outweighs the gain. White resists by cutting at 11. Black pushes through at 12, then plays atari at 14 and crawls out at 16. Continuing up to 22, White loses the semeai by one liberty. (If White connects at 22 in-stead of playing 17, he suffers a Black hane at a, and is no better off.)

Diagram 5: Getting directly to the reason Black lost: When White played tsuke in Figure 1, Black (Black 4 in Figure 1) should have continued as in this diagram.

Although Black 4 is a vulgar move, in this situation one must adopt a patient attitude. It is better to play this and then jump out at 6 making shape. At least tem-porarily this Black group is not going to face an attack. When White plays tobi at 7, Black can play keima at 8 on the left side, herding White into an attack

between Black's upper and lower groups. This way, the outcome of the game is hard to predict.

Conclusion: White's usual continuation is sagari as in Diagram 2. But playing that way it is easy for the game to become simplified, which is disadvantageous for White.

White chose the method in Figure 1. The tsuke was “throwing out” the main prelude to this stratagem. The idea behind this move is very clear from the start. White wanted to strengthen himself and threaten the Black stones. Looking at it from the standpoint of the normal flow of the game, this is the general area where he should play. Exactly because of this, Black underestimated the strength of White's continuation. White “threw out” this tsuke, “attracting” the series of excellent moves that followed, and establishing a superior position over the whole board. This sort of realistic plot is what we call the clever stratagem of “throw out a brick to attract jade”.