British Go Journal No. 12.  August 1970. Page 8.
John Diamond, 3d
The takamoku  play at in Dia 38, is obviously played with different intent to that behind the komoku  discussed in previous articles. Placed at the intersection of the fourth and fifth lines, it leaves the corner open for white to invade, giving black the opportunity to gain an equivalent amount in the form of a wall of influence, towards the right, left or centre as seems appropriate.
White has two main options. These are 1 in Dia 38, playing at the important 3-3 point in the corner to gain a safe group but giving black the opportunity to get what he wants in terms of influence; and 2 in Dia 43, concentrating more on destroying blacks influence but leaving the possibility of Black playing at the 3-3 point leaving white with little corner territory.
This article will deal mainly with the first option as it is simpler but not so well known.
[The diagram numbering is as BGJ, despite the unusual order.]
Whites play here gives Black the opportunity to take the influence he desires, but secures a small corner group from which he can attack later on. Black has three main lines: 2 in Dia 38, 1 in Dia 41 and 1 in Dia 42.
Diagram 42 ||
Diagram 41 |
Taking these possibilities in reverse order, 1 in Dia 42, although pressuring white more immediately than the other two moves, leads to Whites advantage as Blacks main aim of gaining influence and restricting white to a small corner territory has not worked. Blacks possible territory is not very large. Black 3' could have been played at A, answered by B and the result is much the same as the diagram.
Dia 41 is rather better for Black, but it leaves White able to choose which side to extend along, and after the sequence in the diagram, any territory that black could get along the bottom side is threatened by whites invasion at A.
Dia 38, though more complicated, is probably the best for Black. White 3 then forces the exchange up to white 7. This cannot be played at 8 in an attempt to capture black 6 as in return for the sacrifice of this stone black would gain even more influence.
Diagram 39 ||
Diagram 40 |
Black 8' [in Dia 38] could be played at 1 in Dia 39, but the exchange which follows is clearly bad for Black as white is able to stretch to A at some later stage in the game. Should he try to restrict white to the corner with 1 and 3 in Dia 40, 4 and 6 show him his mistake.
Going back to Dia 38, after white 9, Black plays 10, 12 and 14 to restrict white's corner with sente, thus achieving his main objective of gaining influence and still leaving him with sente to direct play to another part of the board.
White 2 in Dia 43 is much the more popular White alternative and will be the subject of the remainder of this article and the next one.
Black has three main lines of attack on White. The one most often used is to play at the 3-3 point (3 of Dia 43). This reduces any possible corner for White and threatens to gain territory along the left side.. The other possibilities are to play at B, threatening to restrict White to the corner, or a pincer play at C, D, E or A.
After 3 of Dia 43 white can ignore the corner completely with his next move and prevent blacks expansion along the left side. But his only answer in the corner is 4, and, after 5-6, black can extend on the left side to make some territory with 7. Whites best point is now A.
Diagram 44 |
If he does not, then Black can play at 1 in Dia 44 and the whole sequence of the diagram is forced. Playing 4' at D is bad for white as the result is that he is enclosed completely (Black plays one point above 3).
Diagram 45 ||
Diagram 46 |
Black 3 in Dia 45 is also a mistake as the rest of that diagram shows.
Black can also play at 1 in Dia 46 (whites vital point) to get the influence he seeks.
Diagram 47 |
When White does not answer 3 of Dia 43 in the corner he can play as in Dia 47 and the rest of the diagram is joseki. Black 6 at A is also possible, and after 7 Black must play at B to prevent white at C.
Diagram 48 ||
Diagram 49 |
Another alternative for black 4' [in Dia 47] is at 1 in Dia 48, when after 7 White can play at A or B.
Also possible, but more complicated, is Dia 49 where the roles are reversed, black getting a fairly large corner in return for white influence.
Part 8 of this article is in BGJ issue 14 .