This 'n' that

Bill Spight · Post by **Bill Spight** » Sat Dec 19, 2015 1:22 am

Old in Go

Click Here To Show Diagram Code: [go]$$Wc Mini-Chinese deferred $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . 2 . . . . . . . . 4 . . . . . . | $$ | . . . , . . . . . , . . . . . X 6 . . | $$ | . . 5 . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . 3 . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . 7 . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . X . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . 1 . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

I like the Mini-Chinese even more than the Chinese configuration, and it seems to have derived from the latter. In modern times, I think that that is so, but the Mini-Chinese is by far the older idea. This example occurred in 1684.

OC, it is from a handicap game, since playing the first move in the corner on the 4-4 point in even games was not revived until the late 19th century. A few years ago I ran across the Mini-Chinese in an old text as a joseki, which meant that it was played in actual games. :w5:

at 7 was possible. In those days the corner approach was by no means preferred to playing on the side.

Let's see how the game developed. White was Honinbo Dosaku Meijin.

Click Here To Show Diagram Code: [go]$$Bcm8 Dosaku (W) - Hoshiai Hasseki $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . X . . . . . . . . X . . . . . . | $$ | . . . , . . . . . , . . . . . X X . . | $$ | . . O . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . . . . . . . . . . . 0 . . . . . . | $$ | . . . . . . . . . . . . . . 9 . 7 . . | $$ | . . . . . . . . . . . . . 8 . . . . . | $$ | . . . . . . . . . . . . . . . 1 . . . | $$ | . . . X . . . . . , . . . 2 . , 5 . . | $$ | . . . . . . . . . . . . . . . O 3 . . | $$ | . . . . . . . . . . . . . . . . 4 6 . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

invades, and play through :b16:

is familiar today. I admit that when I first started studying ancient games, a play like :w17:

took me by surprise. Not that I thought it was bad, but because my impression was that play back then was very territory oriented. So it was, by comparison with today's play, but players still had a keen appreciation of influence and the center. Dosaku, in particular, performed magic there.

Dosaku was already Meijin at the time, back when 9 dan meant something.

Professional ranks were more widely spaced then, so that a 9 dan would give four stones to a 2 dan. Dosaku was so strong that he was said to be 13 dan, two stones stronger than meijin.

Click Here To Show Diagram Code: [go]$$Bcm18 $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . X . . . . . . . . X . . . . . . | $$ | . . . , . . . . . , . . . . . X X . . | $$ | . . O . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . 5 . . . . . . . . . . . . 2 . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . 1 . O . . | $$ | . . . . . . . . . . . . O . . . . . . | $$ | . . . . . . . . . . . . . . X . X . . | $$ | . . . . . . . . . . . . . O . . . . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . . X . . . . . , . . . O . , X . . | $$ | . . . . . . 3 . 4 . . . . . . O X . . | $$ | . . . . . . . . . . . . . . . . O O . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

is ideal.

could have extended farther on the bottom side, but Hoshiai was content to allow :w21:

to build a framework, and then to keep sente and attack on the left side. Black won by 12 points.

BTW, I recommend ancient games to kyu players who focus on territory and have trouble with influence and thickness. Ancient players were generally territory oriented but had a good understanding of influence and thickness, too. There is a lot to learn there.

Bill Spight · Post by **Bill Spight** » Sun Dec 20, 2015 4:16 pm

Old in go (ii)

Click Here To Show Diagram Code: [go]$$Bcm9 Honinbo Doteki (W) - Hoshiai Hasseki $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . 0 . . . . . . . . . | $$ | . . . , . . . . . , . . . . 9 , X . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . 3 5 . . | $$ | . . . . . . . . . . . . . 1 X 2 4 7 . | $$ | . . . . . . . . . . . . . . O X 8 6 . | $$ | . . X , . . . . . , . . . . O , . . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Another Hoshiai Hasseki game.

-

is no longer considered joseki. White's corner is too big. However, it was still considered joseki well into the 19th century, if not later. It appears without comment in Gokyo Seimyo, 1835.

When I was learning go, it was considered a mistake to extend to :w18:

without making the enclosure in the top left corner first. In the 17th century players did not feel so constrained.

Click Here To Show Diagram Code: [go]$$Bcm19 Honinbo Doteki (W) - Hoshiai Hasseki $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . O . . . . . . . . . | $$ | . . . , 4 . . . . , . . . . X , X . . | $$ | . . . 1 2 . . . . . . . . . . . . . . | $$ | . . . . 3 5 . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . X X . . | $$ | . . . . . . . . . . . . . X X O O X . | $$ | . . . . . . . . . . . . . . O X O O . | $$ | . . X , . . . . . , . . . . O , . . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

prevents White from making the high enclosure, which would be good for White.

Click Here To Show Diagram Code: [go]$$Wcm24 Honinbo Doteki (W) - Hoshiai Hasseki $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . O . 8 . . . . . . . | $$ | . . . , O . . . . , . . . . X , X . . | $$ | . 5 7 X O . . . . . . . . . . . . . . | $$ | . 6 3 1 X X . . . . . . . . . . . . . | $$ | . . 4 2 . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . X X . . | $$ | . . . . . . . . . . . . . X X O O X . | $$ | . . . . . . . . . . . . . . O X O O . | $$ | . . X , . . . . . , . . . . O , . . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

After a repeat in the top left corner, :b31:

makes territory and threatens to invade the top side. It also threatens to make a nice framework on the right side, with a double wing. Still, IMO it is too slow.

Where do you guess White played next? This is not a problem. I can't say that it was the best play, but I like it.

skydyr · Post by **skydyr** » Mon Dec 21, 2015 7:34 am

Bill Spight · Post by **Bill Spight** » Mon Dec 21, 2015 1:52 pm

Old fashioned corner approach

Click Here To Show Diagram Code: [go]$$B Old joseki $$ ------------------------ $$ | . . . . . . . . . . . . $$ | . . . . . . . . . . . . $$ | . . . . . . 2 . . 4 . . $$ | . . 3 , 1 . . . . , . . $$ | . . . . . . . . . . . . $$ | . . . . . . . . . . . . $$ | . . . . . . . . . . . . $$ | . . . . . . . . . . . . $$ | . . . . . . . . . . . . $$ | . . . , . . . . . , . .[/go]

strikes us as unusual today, but this was an ancient joseki. Even today, the :w2:

approach to the :b1:

-

enclosure is standard.

Click Here To Show Diagram Code: [go]$$B Old joseki $$ ------------------------ $$ | . . . . . . . . . . . . $$ | . . 5 . 4 . . . . . . . $$ | . . . 6 . . 2 . . . . . $$ | . . 7 , 1 . . . . , . . $$ | . . 3 . . . . . . . . . $$ | . . . . . . . . . . . . $$ | . . . . . . . . . . . . $$ | . . . . . . . . . . . . $$ | . . . . . . . . . . . . $$ | . . . , . . . . . , . .[/go]

Truth to say, :b3:

would not have occurred to me, but it threatens to make a large corner territory, thus inviting :w4:

.

Both of these sequences appear without comment in Gokyo Seimyo.

The following sequence appears in a book by Inoue Yasunobu, 5 dan, Igo GenmyoOchiboShu (1909).

Click Here To Show Diagram Code: [go]$$B Pincer $$ ------------------------ $$ | . . . . . . . . . . . . $$ | . . . . . . . . . . . . $$ | . . . . . . 2 . 3 . . . $$ | . . . , 1 . . . . , . . $$ | . . . . . . 4 . 5 . . . $$ | . . . . 6 . . . . . . . $$ | . . . . . . . . . . . . $$ | . . . . . . . . . . . . $$ | . . . . . . . . . . . . $$ | . . . , . . . . . , . .[/go]

and

attack White from the top side, after which White plays the normal looking :w6:

. Now what?

Click Here To Show Diagram Code: [go]$$B Pincer (ii) $$ ------------------------ $$ | . . . . . . . . . . . . $$ | . . . . . . . . . . . . $$ | . . 9 . . . O . X . . . $$ | . . . , X . . . . , . . $$ | . . 8 . . . O . X . . . $$ | . . 7 . O . . . . . . . $$ | . . . . . . . . . . . . $$ | . . . . . . . . . . . . $$ | . . . . . . . . . . . . $$ | . . . , . . . . . , . .[/go]

Inoue says that :b7:

and

are interesting, a form of praise in Japanese commentary.

Click Here To Show Diagram Code: [go]$$Wm10 Pincer (iii) $$ ------------------------ $$ | . . . . . . . . . . . . $$ | . . . . . . . . . . . . $$ | . . X 6 7 . O . X . . . $$ | . . 1 5 X 8 . . . , . . $$ | . . O 4 3 . O . X . . . $$ | . . X 2 O . . . . . . . $$ | . . . . . . . . . . . . $$ | . . . . . . . . . . . . $$ | . . . . . . . . . . . . $$ | . . . , . . . . . , . .[/go]

Then

leads to

and the following sequence.

Click Here To Show Diagram Code: [go]$$Wm18 Pincer (iv) $$ ------------------------ $$ | . . . . . . . . . . . . $$ | . 2 . . . . . . . . . . $$ | . 1 X X O 5 O . X . . . $$ | . . O O B B . . . , . . $$ | . . O X O . O . X . . . $$ | . 3 X X O . . . . . . . $$ | . 4 . . . . . . . . . . $$ | . . . . . . . . . . . . $$ | . . . . . . . . . . . . $$ | . . . , . . . . . , . .[/go]

Then

and

prevent a ladder and :w22:

serves to capture the :bc:

stones.

Click Here To Show Diagram Code: [go]$$Bm23 Pincer (v) $$ ------------------------ $$ | . . . . . . . . . . . . $$ | . X . . . . . . . . . . $$ | 3 O X X O O O . X . . . $$ | . 1 O O X X 4 . . , . . $$ | . 2 O X O 6 O . X . . . $$ | 5 O X X O . . . . . . . $$ | . X . . . . . . . . . . $$ | . . . . . . . . . . . . $$ | . . . . . . . . . . . . $$ | . . . , . . . . . , . .[/go]

Click Here To Show Diagram Code: [go]$$Bm29 Pincer (vi) $$ ------------------------ $$ | . . . . . . . . . . . . $$ | . X . . . . . . . . . . $$ | X . X X O O O . X . . . $$ | . X O O 1 2 O . . , . . $$ | 3 O O X O O O . X . . . $$ | X O X X O . . . . . . . $$ | . X . . . . . . . . . . $$ | . . . . . . . . . . . . $$ | . . . . . . . . . . . . $$ | . . . , . . . . . , . .[/go]

Inoue states the obvious: Very bad for White.

An amusing result.

bayu · Post by **bayu** » Mon Dec 21, 2015 2:17 pm

Bill Spight wrote:Old in go (ii)

$$Wcm24 Honinbo Doteki (W) - Hoshiai Hasseki
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . O . 8 . . . . . . . |
$$ | . . . , O . . . . , . . . . X , X . . |
$$ | . 5 7 X O . . . . . . . . . . . . . . |
$$ | . 6 3 1 X X . . . . . . . . . . . . . |
$$ | . . 4 2 . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . X X . . |
$$ | . . . . . . . . . . . . . X X O O X . |
$$ | . . . . . . . . . . . . . . O X O O . |
$$ | . . X , . . . . . , . . . . O , . . . |
$$ | . . . . . . . . . . . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------

Click Here To Show Diagram Code
[go]$$Wcm24 Honinbo Doteki (W) - Hoshiai Hasseki $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . O . 8 . . . . . . . | $$ | . . . , O . . . . , . . . . X , X . . | $$ | . 5 7 X O . . . . . . . . . . . . . . | $$ | . 6 3 1 X X . . . . . . . . . . . . . | $$ | . . 4 2 . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . X X . . | $$ | . . . . . . . . . . . . . X X O O X . | $$ | . . . . . . . . . . . . . . O X O O . | $$ | . . X , . . . . . , . . . . O , . . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

After a repeat in the top left corner, makes territory and threatens to invade the top side. It also threatens to make a nice framework on the right side, with a double wing. Still, IMO it is too slow.

Where do you guess White played next? This is not a problem. I can't say that it was the best play, but I like it.

I've got a honest question about pratique.
When you say: this is no joseki anymore. How do you know? I'm not disputing whether the sequence in the game above is still joseki or not. I believe you that it is outdated. I'm wondering, how could I possibly have found out. Did a book or someone who knows tell you? Do you simply observe, that it doesn't show up anymore in pro games? Kogo still has the joseki in (and says GOOD VARIATION), it appears in the Go joseki app for Android (which doesn't seem to be based on Kogo) and I was very happy when I finally learnt it. What are the sources that tell you, that something is outdated?

Bill Spight · Post by **Bill Spight** » Mon Dec 21, 2015 3:03 pm

bayu wrote:I've got a honest question about pratique.
When you say: this is no joseki anymore. How do you know? I'm not disputing whether the sequence in the game above is still joseki or not. I believe you that it is outdated. I'm wondering, how could I possibly have found out. Did a book or someone who knows tell you? Do you simply observe, that it doesn't show up anymore in pro games? Kogo still has the joseki in (and says GOOD VARIATION), it appears in the Go joseki app for Android (which doesn't seem to be based on Kogo) and I was very happy when I finally learnt it. What are the sources that tell you, that something is outdated?

The Suzuki-Kitani Small Joseki Dictionary (1966), does not even call it an old joseki, but simply says that it is favorable for White (in this case) because the corner is so large. I found out that it was an old joseki from its appearance in Gokyo Seimyo.

One problem seems to be that the outside stones need bolstering. For instance, I learned this as joseki.

Click Here To Show Diagram Code: [go]$$ $$ . . . . . . . . . . | $$ . . . . . . . . . . | $$ . . . . . . . . . . | $$ , . . . . . , . . . | $$ . . . . . . . . . . | $$ . . . . 9 . . . . . | $$ . . . . . . 3 5 . . | $$ . . . . 1 X 2 4 7 . | $$ . . . . . O X 8 6 . | $$ , . . . . O , . . . | $$ . . . . . . O . . . | $$ . . . . . . . . . . | $$ . . . . . . . . . . | $$ ---------------------[/go]

Inoue (1909) gives this sequence.

Click Here To Show Diagram Code: [go]$$ $$ . . . . . . . . . . | $$ . . . . . . . . . . | $$ . . . . . . . 9 . . | $$ , . . . . . , . . . | $$ . . . . . . . . . . | $$ . . . . . . . . . . | $$ . . . . . . 3 5 . . | $$ . . . . 1 X 2 4 7 . | $$ . . . . . O X 8 6 . | $$ , . . . . O , . . . | $$ . . . . . . O . . . | $$ . . . . . . . . . . | $$ . . . . . . . . . . | $$ ---------------------[/go]

Bill Spight · Post by **Bill Spight** » Tue Dec 22, 2015 9:59 am

Back to the Doteki - Hoshiai game.

Both skydyr and bayu favored an approach to the bottom left corner. So did Doteki, but his approach was a bit unusual.

Click Here To Show Diagram Code: [go]$$Wcm32 Honinbo Doteki (W) - Hoshiai Hasseki $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . O . X . . . . . . . | $$ | . . . , O . . . . , . . . . X , X . . | $$ | . O O X O . . . . . . . . . . . . . . | $$ | . X O O X X . . . . . . . . . . . . . | $$ | . . X X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . 3 . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . X X . . | $$ | . . 1 . . . . . . . . . . X X O O X . | $$ | . . . . . . . . . . . . . . O X O O . | $$ | . . X , 2 . . . . , . . . . O , . . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

allows

, a big enclosure, but then :w34:

largely negates Black's influence on the left side.

The first time I saw that approach to the 3-4 was as a suggestion by Go Seigen in his 21st Century Go set, against the Chinese Fuseki. (Today the two space high approach is more popular.) It was a brilliant idea, but I suspect that Go had seen it in his studies when he was a kid.

Click Here To Show Diagram Code: [go]$$Wcm32 Honinbo Doteki (W) - Hoshiai Hasseki $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . O . X . . . . . . . | $$ | . . . , O . . . . , . . . . X , X . . | $$ | . O O X O . . . . . . . . . . . . . . | $$ | . X O O X X . . . . . . . . . . . . . | $$ | . . X X 8 . . . . . . . . . . . . . . | $$ | . . . . 7 . . . . . . . . . . 4 . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . O . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . X X . . | $$ | . . O . . . . . . . . . . X X O O X . | $$ | . . . . . 6 . 9 . . . . . . O X O O . | $$ | . . X , X . . . . , . . . . O , . . . | $$ | . . . . . . 5 . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

stakes out the right side, but then :w36:

approaches the bottom left corner. How to respond is not all that obvious. :b37:

strikes me as a bit slow, as White already has a base on the left side. After taking his kikashi against the top left Black group, :w40:

is enterprising. (BTW, I have always liked such keimas towards the center.

) Doteki won by 7 points.

Bill Spight · Post by **Bill Spight** » Wed Dec 23, 2015 5:30 pm

Very ancient joseki and tricky play

Click Here To Show Diagram Code: [go]$$W Ancient joseki $$ -------------------- $$ | . . . . . . . . . . $$ | . . . . . . . . . . $$ | . . . . . 1 . . . . $$ | . . . X . . . . . , $$ | . . . . . 3 . . . . $$ | . . . . . . . . . . $$ | . . 2 . . . . . . . $$ | . . . . . . . . . . $$ | . . . . . . . . . . $$ | . . . , . . . . . ,[/go]

-

is a very ancient joseki. In fact, these are the opening moves of the oldest game record in my GoGoD database, dating to 196.

Click Here To Show Diagram Code: [go]$$W Belly attachment $$ -------------------- $$ | . . . . . . . . . . $$ | . . . . . . . . . . $$ | . . 4 3 . O . . . . $$ | . . 1 X . . . . . , $$ | . . 5 2 . O . . . . $$ | . . . . . . . . . . $$ | . . X . . . . . . . $$ | . . . . . . . . . . $$ | . . . . . . . . . . $$ | . . . , . . . . . ,[/go]

The belly attachment, :w1:

, is tricky. The nobi, :b2:

, is a solid reply.

After :w5:

, where does Black play?

(Answer after Christmas

)

Hint:

Bill Spight · Post by **Bill Spight** » Mon Dec 28, 2015 8:57 am

Well, it's after Christmas. Happy Saturnalia!

The answer is hidden for the benefit of later readers.

Hayashi Gembi (1835) gives a few variations, as does Inoue Yasunobu (1909). Two of the sequences are virtually the same in each. (I have identified the variations in Inoue.)

BTW, it's rather nice to find a joseki (through the White jump) that has lasted a couple of millenia. The large knight response is not played much these days, but I do not think that it has been deemed inferior. To have lasted so long, the joseki must be rather go-ish.

The variations (after :w1:

):

Bill Spight · Post by **Bill Spight** » Thu Dec 31, 2015 10:01 pm

On thoroughness

Over time I have come to appreciate thoroughness more and more. A good example is how Mr. K treats life and death. See http://mrkigo.sakura.ne.jp/ksikatuindex.html . He explores basic life and death problems in depth, so that the solver is prepared for anything. Also, I have found unexpected delights in things that I thought I already knew.

Here is an example from my own study not too long ago.

Click Here To Show Diagram Code: [go]$$W 2x4 in the corner $$ -------------- $$ | . . . . O X . $$ | . . . . O X . $$ | O O O O O X . $$ | X X X X X X . $$ | . . . . . . .[/go]

In this well known position Black to play can make ko or seki. White to play can live easily.

Click Here To Show Diagram Code: [go]$$W White lives $$ -------------- $$ | . 1 . . O X . $$ | . . . . O X . $$ | O O O O O X . $$ | X X X X X X . $$ | . . . . . . .[/go]

In the interest of thoroughness, I looked at other plays. How bad are they?

Click Here To Show Diagram Code: [go]$$W Status? $$ -------------- $$ | 1 . . . O X . $$ | . . . . O X . $$ | O O O O O X . $$ | X X X X X X . $$ | . . . . . . .[/go]

Suppose that White makes a crazy play on the 1-1. How bad is it? Can Black kill or make ko?

I'll leave this as a little problem. Enjoy!

Bill Spight · Post by **Bill Spight** » Sat Jan 02, 2016 9:34 am

Answer hidden for those who might like it to be.

I find the answer charming. A hidden delight in a strange position.

Here is another position where thoroughness produced delight for me.

Click Here To Show Diagram Code: [go]$$B Deep sente $$ --------------------- $$ | . 1 . . . X . . . . $$ | O O . O O O X . X . $$ | . X O O X X X . . . $$ | . X X X . . . . . . $$ | . . . . . . . . . . $$ | . X . . . . . . . . $$ | . . . . . . . . . .[/go]

The other two sente plays I saw at a glance. Looking further, I saw this one.

This play adds no value in a real game. However, there may be other positions where the idea of this play bears fruit. Besides, it is a joy in itself.

Happy New Year!

EdLee · Post by **EdLee** » Sun Jan 03, 2016 7:41 am

Bill Spight · Post by **Bill Spight** » Sun Jan 03, 2016 9:39 am

EdLee wrote:
Bill Spight wrote:there may be other positions where the idea of this play bears fruit.
Hi Bill, Happy 2016.
$$B
$$ ---------------------
$$ | . . . . . . . . . .
$$ | O O . . O . X . . .
$$ | O X O O X X . X . .
$$ | . X X X . . . . . .
$$ | . X . . . . . . . .
$$ | . . . . . . . . . .

Click Here To Show Diagram Code
[go]$$B $$ --------------------- $$ | . . . . . . . . . . $$ | O O . . O . X . . . $$ | O X O O X X . X . . $$ | . X X X . . . . . . $$ | . X . . . . . . . . $$ | . . . . . . . . . .[/go]

Thanks, Ed!

Bill Spight · Post by **Bill Spight** » Sun Jan 03, 2016 6:57 pm

No Pass Go

Way back when, when I was around shodan, I hit upon the idea of no pass go, which I called Nimgo, because the player without a move would lose. I thought that it might be useful for beginners, since it has a well defined game ending condition. That is not the case, at least not for straight no pass go, but I did not understand the game.

I had not heard of the group tax, but it is plain that in this corner, assuming that the enclosing White stones are alive,

Click Here To Show Diagram Code: [go]$$W Zero $$ ------------ $$ | C X C X O . $$ | X X X X O . $$ | O O O O O . $$ | . . . . . .[/go]

White cannot play on the marked eye points, and Black will not play there, unless forced. (In combinatorial game theory, the corner is worth 0. OC, I had no idea of CGT at that time.)

One advantage for beginners, I thought, was that life and death questions would naturally be settled by play. True enough.

Furthermore, I imagined that it would be plain that for you to spend four plays to capture a dead stone would cost nothing, because your opponent would also be making four plays inside his own territory or adding four dead stones to your territory. And also, it would be plain that playing a dead stone inside your opponent's territory to force him to capture it would not gain anything. That idea was a mistake. No pass go, at least straight no pass go, is not so simple, as we shall see.

It was only much later, when I began to study CGT, that I began to understand no pass go. It shows its strangeness pretty quickly.

For instance, what is this marked area worth? (Outer stones alive, by convention.)

Click Here To Show Diagram Code: [go]$$B $$ ------------------ $$ | C X C X O C O X . $$ | X X X X O O O X . $$ | C C X O O C O X . $$ | X X X O C O X X . $$ | C C X O O C O X . $$ | X X X O C O O X . $$ | O O O O O O X X . $$ | X X X X X X X . . $$ | . . . . . . . . .[/go]

It may look like Black is one point ahead here, with four moves (points) to three. However:

Click Here To Show Diagram Code: [go]$$B Black first $$ ------------------ $$ | 5 X 7 X O 4 O X . $$ | X X X X O O O X . $$ | 1 . X O O 6 O X . $$ | X X X O 8 O X X . $$ | 3 2 X O O . O X . $$ | X X X O . O O X . $$ | O O O O O O X X . $$ | X X X X X X X . . $$ | . . . . . . . . .[/go]

After

the local result is 0, with only the "group tax" points remaining.

Likewise:

Click Here To Show Diagram Code: [go]$$W White first $$ ------------------ $$ | 6 X 8 X O 3 O X . $$ | X X X X O O O X . $$ | 4 1 X O O 5 O X . $$ | X X X O 7 O X X . $$ | 2 . X O O . O X . $$ | X X X O . O O X . $$ | O O O O O O X X . $$ | X X X X X X X . . $$ | . . . . . . . . .[/go]

After

the result is also 0. Which means that the original position is worth 0.

And what that means is that the two two point eyes for Black are worth the same as the three one point eyes for White. How can that be? The variations show why. In each one White gets one play inside one of Black's two point eyes. Black gets four plays there, but White gets one, for a net of three plays for Black.

And what that means is that each two point eye is worth 1.5 points (moves).

And that means that, as the end of the no pass go game approaches -- and maybe earlier --, it is generally worthwhile to play inside your opponent's territory. Just as some beginners believe about regular go. :lol:

Jhyn · Post by **Jhyn** » Sun Jan 03, 2016 9:15 pm

Bill Spight wrote:And that means that, as the end of the no pass go game approaches -- and maybe earlier --, it is generally worthwhile to play inside your opponent's territory. Just as some beginners believe about regular go.

A semedori of sorts, then. It looks highly nontrivial to find a balance between playing inside your own territory to increase its value by preventing your opponent from playing there, and playing inside your opponent's territory to reduce its value. I wonder if this impacts significantly the strategy. Have you given it a try on 9x9?

Life In 19x19

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