Life In 19x19

The forum's going through one of its now too frequent quiet patches, so this is an attempt to provide something worth commenting on or asking about.

There are a few moves that long ago struck me with such wonder that I still vividly recall thinking, for example, "that must be a misprint." To this day, whenever I see these moves I still get that feeling of "Eh!" even though I know what's happening now.

I just came across one of these while inputting an old pro game. It's the triangled move. I know I'm not alone in my uneasy reaction to this move because I've noticed that even very strong amateurs hardly ever seem to have this arrow in their quiver - so much so that it's almost a shibboleth for being a pro. I think I recall words by Fujisawa Hideyuki to that effect. too.



Discussion of this move will probably centre on the concept that walls must have ears and on the value of inviting the opponent to poke the elephant's eye, and you can probably find something to say about a tiger's mouth, but if you find something to say about a nostril or an Adam's apple please do not hesitate to join the anatomy class.

Apart from the reason for the move itself, it will be necessary to compare it with e.g. shape moves such A, B and C which are inferior here.

From my perspective:
Well, if black goes for the elephant's eye directly, white can use forcing moves to sacrifice the two white stones and threaten the black stones on K3 and K5 at the same time. White still has the aji in the corner as well. White could also sacrifice the single stone to come out and damage black's corner group.

As for the alternatives, playing C seems to look to live locally and sealed in, which can't be good. Playing A encourages black to split the white position through a narrow gap. B is more nuanced, but it feels like it is harder to sacrifice one or the other part of the group effectively, and black can take eyespace while threatening to cut, leaving white with a heavy group.

I'm looking at alternatives to poking out the elephant's eye for black, but haven't found anything that looks particularly compelling locally, which may be endorsement enough. It may also be endorsement of my poor reading, of course.

Reference games.

This is the best I can do

I find that trying to really understand why such moves are 'good' is fairly futile. In the present case we have to account for the results from searching GoGoD with the following pattern. Note that these are the only six cases that showed up with the marked White stone in place (two examples of the 'good' move and four others).

Click Here To Show Diagram Code

[go]$$Bc Search Pattern
$$
$$| . . . , . . . . . , .
$$| . . . . . . . . . . .
$$| . . W . . . . . . . .
$$| . . . . . . . . . . .
$$| . . . X . . . . . . .
$$| . . . . . . . . . X .
$$| . . . X . O . . . , .
$$| . . . . X O . . . X .
$$| . . . . . . . . . . .
$$| . . . . . . . . . . .
$$+ - - - - - - - - - - -[/go]

Cases where the 'good shape' move was chosen: Cases where an alternative was chosen: Then we have the situation with a more general search. The pattern below turns up 97 matches with 'd' below being played 10 times. More frequent alternatives are 'a' through 'c' (40, 14, and 14 cases respectively). Perhaps more to the point, the 'good shape' play was last seen in July 1987. White has always chosen something else (including tenuki) in the 37 games where this position arose since then. As usual, I have no clue what these guys are thinking. Note however, that IMHO any discussion of the merits of 'd' really should start with a comparison to 'a' rather than any other move (again, not because I understand either of them!).

Click Here To Show Diagram Code

[go]$$Bc Search Pattern
$$
$$| . . . . . c a . . . .
$$| . . . X . . b d . . .
$$| . . . . . . . . . X .
$$| . . . X . O . . . , .
$$| . . . . X O . . . X .
$$| . . . . . . . . . . .
$$| . . . . . . . . . . .
$$+ - - - - - - - - - - -[/go]

I will provide a weaker analysis than my esteemed thread contributors.

I will merely say that I am aware of the haengma shown. In is covered in the book "This is Haengma" by Kim Sung-rae, but in a very different context, so the ideas are only partially applicable in the original position given in this thread.

Click Here To Show Diagram Code

[go]$$B black to play
$$ | . . . . . . . . . . . .
$$ | . . . , . . . . . , . .
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . g . . .
$$ | . . . . . 1 f c O . . .
$$ | . . O . . . a . . x . .
$$ | . . . , b e . X . O . .
$$ | . . . O . d . X O . . .
$$ | . . . . . h . . . . . .
$$ | . . . . . . . . . . . .
$$ -------------------------[/go]

In this case, is the correct haengma. The elephant eye cut at 'a' is refuted by black 'b'. (This requires reading beyond my level, however.) Although it doesn't say this explicitly in the book, I recall vaguely that has a feeling of making miai of 'c' and a move around 'd' or 'e', however, in this case that usual thinking is wrong because black really doesn't want to to play the 'c'-'g' exchange as it erases the aji of the cut at 'x'. If white plays the vital point at 'd' in response to , black can play e-b-h and protect the cut at 'a' that way, leaving the weakness at 'x'. For a knight's move like 'f' in this case, the vital point is 'd' and I may use the same vital point in the originally posted position, which is why I wouldn't play the knight's move in the position given by the OP.

So the big diagonal in the original post does not seem weird to me. I would consider it as a candidate move but likely would not play it unless I could read out the result of my opponent's playing at the elephant eye. That might depend on how much time I have in the game, how cocky I feel, or a number of other factors.

In the OP, I suspect the final analysis will not recommend any variations that hurt the white C8 stone, as this is a valuable stone and there is aji in the corner.

Thank you for inspiring me to revisit "This is Haengma," though.

I know of ear moves but have not heard the expression "walls must have ears." What's that about?