Book reference for the ideal distance from a wall?

[Bill Spight]

Among the first go books I ever bought was a set of small books about the basics, published by the Nihon Kiin. One of them provided an extensive discussion of the proverb in question. As John Fairbairn indicates, it is not about walls in general, but about standing walls of stones connected linearly with the bottom stone on the third line. The main point of the discussion was that, unless the opponent had stones in the vicinity, an invasion of those walls plus the indicated extension was not a good idea. Generally the invasion could be killed. I have not seen any other book that went into such detail, and those little books are long out of print.

Pro games show frequent violations of the proverb, usually by making closer extensions, particularly in the presence of opposing stones, and sometimes by making wider extensions, or no extension at all. (Walls with eye shape do not require an extension, and the proverb does not apply to them, but sometimes even linear walls do not get an immediate extension.)

[RobertJasiek]

Except when restricting one's view artificially like allegedly for the proverb, there is no need to avoid consideration of walls of any shape (needing an extension for eyespace at all).

[John Fairbairn]

Another example of an amateurish professional, this time Honinbo Shusai:



In 270 examples of this three-stone wall opening, White extends with a three-space gap only about 90 times, so it is the commonest single choice but nowhere near a majority choice. Which means, I suppose, most pros are amateurs... (or worse: "Japanese 9-dans").

Also, the three-space choice actually has by far the worst winning ratio (about 42%). The best is the knight's move into the centre (60%).

Tenuki is very common, and this opening, with or without tenuki, illustrates some very interesting aspects of go strategy that normal joseki evaluation criteria completely miss. One is that this wall-based group is not just resilient when attacked, but usually manages to stave off the opponent's attack without incurring any significant collateral damage. There is a class of josekis to which this applies, the most notable examples being when a low approach to a komoku is attacked with a widish pincer and the pincee then jumps out to the fifth line above the pincer. It seems that it is the angle of egress into the centre that counts for much.

The other strategic aspect of this three-stone wall is that it conveniently fits into a well known sacrifice strategy where it can be sacrificed because the opponent will have to use far more than three stones to capture it. This no doubt is why it is often treated with tenuki. In general straight walls of stones are often considered for sacrifices because they are, in one sense, inefficient in that they can be difficult to turn into true thickness.

This opening is still being played and so merits some study. Even by professionalish amateurs.

[RobertJasiek]

:)

Such reminds me of my 9-7 openings when I play forcing moves against corners and then tenuki. Such strategies have been becoming more popular also among European 4d+ for the last two years. Single stone forcing moves were played also by others.

However, your professional examples differ: the forcing moves install a heavy group while we European amateurs prefer light groups (typically only 1 or 2 stones). A heavy group cannot be easily discarded permanently by tenuki. Therefore, we see some soon extension in the pro examples you have shown thus far.

Again, I am not convinced by White's strategy (C10 at C11 is at a better place). Do we see such examples as intentional hamete in no-komi games, which hope for Black's suboptimal exploitation of the aji?

[RobertJasiek]

Somebody forgot to tell Shusaku, Shuho, Shusai and a host of 9-dans.

Kombilo search among 70179 GoGod games, ignoring 2 unfinished games. Pattern without fixed colour:

$$W
$$ ----------------
$$ | . . . . . . . .
$$ | . . . . . . . .
$$ | . . . . X . . .
$$ | . . X X . X . .
$$ | . . O O O . . .
$$ | . . . . . . X .
$$ | . . . . . . . .
$$ | . . . . . . . .
$$ | . . . . . . . .
$$ | . . O , . . . .
$$ | . . . . . . . .

Click Here To Show Diagram Code

[go]$$W
$$ ----------------
$$ | . . . . . . . .
$$ | . . . . . . . .
$$ | . . . . X . . .
$$ | . . X X . X . .
$$ | . . O O O . . .
$$ | . . . . . . X .
$$ | . . . . . . . .
$$ | . . . . . . . .
$$ | . . . . . . . .
$$ | . . O , . . . .
$$ | . . . . . . . .[/go]

1807-08-22a: Nagasaka Inosuke - Kadono Matsunosuke (B), 143g
1914-06-08a: Nagahama Hikohachi - Kogishi Soji (B), 33a
1917-12-12: Fujita Toyojiro - Iwamoto Kaoru (B), 11b
1925-04-00b: Honinbo Shusai - Segoe Kensaku (B), 17b
1928-00-00a: Go Seigen - Wang Youchen (W), 42f-
1929-11-07b: Takahashi Shigeyuki - Hashimoto Utaro (B), 15c
1991-12-06a: Kim Heui-chung - Kim In (B), 14d-
1993-12-28b: Yang Keon - Kim Seung-chun (B), 27h
2004-12-26b: Chang Hao - Ch'oe Ch'eol-han (B), 59e

Summary:
- no komi games: 6 wins by the attacker, 0 wins by the defender
- komi games: 2 wins by the attacker, 1 win by the defender
- total: 8 wins by the attacker, 1 win by the defender

Conclusion:
The four-space extension wins in 11% of the games and loses in 89% of the games if the attacker plays the keima punishment.

[John Fairbairn]

Conclusion:
The four-space extension wins in 11% of the games and loses in 89% of the games.

You know perfectly well this is a silly conclusion.

1. The sample is too small.

2. The opening usually has black in the corner. We expect Black to make a big plus score anyway in no-komi games.

3. The knight's move in several of these games was played late in the game when many adjacent stones affected the position, so it cannot be said to be the decisive factor (and even without adjacent stones there is nothing to say mistakes elsewhere did not decide the game).

You are sounding desperate to shore up your theory. I think it's more honest to ask what the pros might know that you don't.

Remember I am not saying that move A is better or worse than B. I am simply pointing out that pros do not share your rigid thinking. Again, ask why?

[RobertJasiek]

OC, statistics prove nothing. I show my statistics as a reminder that your statistics in http://www.lifein19x19.com/forum/viewto ... 84#p186984 also prove nothing because they refer to an even less related (earlier) shape.

You need not point out a rigid thinking of mine because I have already clarified in this thread (by specifying to presume a 3rd line extension for the question about the usually right distance of such an extension, meaning that other moves can be considered anyway) and with the flexibility in my principle in the book that my thinking is not rigid. Uberdude, just because I do not provide a complete discussion of whole board strategy in every message does not mean that my rigid thinking should be presumed.

A reference to pro thinking and asking pros do not help us because we have hardly any chance to know their thinking in those games about the extension. We need to study the games and draw conclusions from that.

[Uberdude]

Uberdude, just because I do not provide a complete discussion of whole board strategy in every message does not mean that my rigid thinking should be presumed.

Then don't use such strong words as "correct" and "punishes" without qualifiers.

[RobertJasiek]

Sounds fair enough, but you know the consequence of expecting, also in informal discussion, everybody everywhere to write "usually correct", "usually punishes" etc. E.g., you yourself would have to replace "makes almost sente" by something like "depending on the global positional context can make an immediate sente or prepares a severe follow-up", "threatens to separate" by "usually threatens to separate", "provides one such global position" by "it can be argued that it is such a global position" etc. Do you really want everybody to apply the same precision in informal texts I apply to formal definitions? Great! :)

[Uberdude]

There is a balance to be had between precision and readability of language. I thought mine struck a good one, whilst yours did not.

[John Fairbairn]

Sounds fair enough, but you know the consequence of expecting, also in informal discussion, everybody everywhere to write "usually correct", "usually punishes" etc. E.g., you yourself would have to replace "makes almost sente" by something like "depending on the global positional context can make an immediate sente or prepares a severe follow-up", "threatens to separate" by "usually threatens to separate", "provides one such global position" by "it can be argued that it is such a global position" etc. Do you really want everybody to apply the same precision in informal texts I apply to formal definitions? Great!

No, Robert. This illustrates nicely the problem with monolithic thinking: picking up on one thing and ignoring whatever may suit everyone else. Uberdude mentioned TWO things: "Then don't use such strong words as "correct" and "punishes" without qualifiers." You picked up on "qualifiers" but ignored "strong." If your original statement (move A was "correct" and move B was a "refutation as it threatens the connection" had been expressed as move A was "more usual" and move B simply "threatens the connection", there would have been fewer words, not more, and the meaning would have actually been clearer, and I don't think anyone would have commented on it (to oneself at most, perhaps, with an internal shrug and a "well, ok for beginners, I suppose...").

Your comment that we can't know what the pros thought can also be challenged.

In the case of Shusai versus Segoe we have commentaries by both players and by an outsider. I think it is instructive to look at these. The full game is below.



SHUSAI
“Black 17 is a fine move appropriate to this juncture.
“(Supplement: Black 17 is the kind of good point known as “staring in eight directions.” It has the implication of a two-space pincer against White 12 next at A [H3] and also has a long-term aim at invasion on the right side at B [Q7], and also it copes in a far-off way with a White attachment at C [D15]. If Black omits this move, and White does attach at C in the upper left, he will have no way to push in severely with the hane at D [D16]. If he nevertheless does, what follows is White E [C16], Black F [E16], White connection at G [C17]. Then if Black tries the ladder at H [D14], White can run out at I [E15] and Black will have nowhere to play. But with Black 17 in place, the ladder works for him, so that when Black does hane at D it does not make sense for White to atari on the inside at E, so he has no option but to atari on the outside at F. Therefore White has to proceed on the basis of taking into account that he cannot play at C immediately, and so he first defends at 18. There is no move as powerful here as Black 17.)”

The "supplement" here is Kido's expansion of what the Master said.

SEGOE
“This was a game in which White was fertile with variations. I won this game to end up with four wins in a row, but there is no record of who I played in the fifth game.”
His first comment on the moves was: “The result of the sequence White 30 to 36 was to make the game full of possibilities.”

Segoe's only other comment was on the sequence 129 to 139, in the upper left, which he said was mochikomi and so a bit of a loss for Black.

However, Shusai commented that White 30 was not well timed. He said, “The timing dictated that I should first have played the knight’s move at R18 in the upper right, or the diagonal attachment at C16 in the upper left to see how Black will respond.” There is detailed explanation of this and quite of lot of other commentary, omitted here but none of it relates to the right side. However, at the end there is a summary of the flow of the game which says that Black was able to maintain the advantage of first move by proceeding nice and cautiously and he got his reward in the middle game with a superior position. Shusai played well to lose by only one point (Shusai criticised only two of his own moves, 88 (“unreasonable,” should be 89) and 218 (the losing move).

So what we see here is that there is no sense that Shusai regretted his wide move on the right. If anything it gave him richer possibilities and his only regret in that area was that he mistimed White 30. In the actual game the connection never came under direct threat or caused any commentable problems. Black 17 (which was also a common move even against the narrow extension, incidentally) caused Shusai regret, but the suggestion appears that this is first because of its effect on the lower side (which is where he chose to respond - the not the right side) and second on the upper left, which is where Shusai would have loved to have played (to justify his 3-to-1 stone investment), but he was inhibited from playing there for a long time because of the ladder). Further, the one comment that does relate to the right side simply says Black has a long-term aim (nerai) there. To me there is a big difference between a long-term aim and a threat.

We also see that Segoe chose not to comment on the right side at all.

On top of all that, although a statement that "White R9 [instead of White 14] is more usual and Black 15 threatens the connection" would not have been objectionable, it doesn't help us judge the whole game in the way Shusai+Kido or Segoe's comments do.

If, however, we look at the position purely as a local joseki, it seems that there is a better way of phrasing the otherwise unobjectionable comment. Kitani, for example, says of this joseki that after R9 the point N6 (Black 17) is important for both players. Then he adds that This applies even more so if the extension is wider, to R10. There is no hint of criticism in that - just an implicit reminder that timing of the knight's move will matter, which is precisely what we saw in the Segoe-Suzuki game, where it must be noted, Segoe did not respond to the wide move at once; he played in the upper left first, and it was that that apparently caused Shusai problems.

My argument is that by being less dogmatic and prescriptive than RJ, the Japanese commentaries have been much more informative about the whole game, yet have also aided study of the joseki qua joseki by illustrating its rich possibilities and hints for both sides, and they have done this with no significant extra wordage. I have added more than of few words, of course, but that should not be allowed to obscure the leanness of the Japanese commentaries.

[wineandgolover]

I have not read much, if anything, by Yang Yilun but I know he's popular with American students. Perhaps they can tell us: is there any sense in which he may be tailoring to a western audience? And if so, is that a good thing?

Yes, he definitely tailors for Western students, and overall I think it's a good thing. Its biggest drawback is that for some students the principles become rules (as the OP requested) that they always apply, without necessarily accounting for the neighboring stones.

From the introduction of Fundamental Principles of Go:

Much of the material in this book is definitely not available in English language go literature. In fact, I doubt that this material can be found anywhere in the world because Mr. Yang did not formulate these ideas until after he arrived in the United States in 1986. He once told me that when he taught go in China, his students would say, “Yes, Teacher, I believe you.” After arriving in the US, however, he began encountering students who said, “Yes, Teacher, I believe you, but why? How is it that a small change—one line up or down, left or right—can make such a drastic change in the analysis? There must be something fundamental going on here, but what is it? I don’t understand.” This forced Mr. Yang himself to think about the meaning of the moves. The result of those thoughts is the book you now hold in your hands, a truly Western theory of go.

[RobertJasiek]

It is impressive that enough old commentaries exist to allow citation of a commentary on a related game, thanks John!

It remains unclear why the 4-space extension would given White "richer possibilities". Different possibilities for sure, but why richer? Black's richer invasion possibilities are hardly discussed. In particular, the pro comments do not discuss the disadvantages of the wide extension and do not compare well the 3- with the 4-space extension. In particular, it is worth discussing why Black 21 does not invade on the right side. It is easy for Shusai not to regret his wide extension because Black did not challenge it. Instead, Black waited until White 28 could establish a reasonable shape. The common sense comments by the professionals are all fine and well, but they avoid the more interesting discussion about the extension. If I am dogmatic and prescriptive about something, it is not move 14 but the duty to reflect the characteristics of also this move.

[Bki]

As for why professionals would not invade immediately, I think the answer is simple : other moves were bigger/more urgent, and White coming back to solve the problem is a win in itself.

[RobertJasiek]

White coming back to solve the problem is a win in itself.

It can easily be an inefficient move (loss in the global context) because White plays two moves where he could have settled the connection and life by just one move.