This 'n' that

Bill Spight · Post by **Bill Spight** » Fri Nov 04, 2016 8:00 am

Continuing piecemeal:

For quite some time I have had the impression that currently the pros are emphasizing the sides in the opening more than they did in the 20th century (after the New Fuseki period). OC, that is obvious in the Chinese fuseki and mini-Chinese, as well as the Kobayashi fuseki, in which a side extension is played before making an enclosure. But it has seemed to me that the pros have recently gone even further. In my exploration of the side base in the opening I had not planned to look at recent games, as I think that, even if the advanced thinking behind the plays is different these days, the fundamentals have not changed since the 17th or 18th century. I may change my mind as I explore further.

Gotta run now.

Bill Spight · Post by **Bill Spight** » Mon Apr 24, 2017 7:18 am

Something new.

TrueTears recently posted an interesting game against CrazyStone DL with the 5 kyu setting on Android. ( http://www.lifein19x19.com/forum/viewto ... =4&t=14181 )

One question that it provokes is whether Black has a ko threat in the top left corner for the 1/3 pt. ko (marked).

Click Here To Show Diagram Code: [go]$$Bc Black ko threat in top left corner? $$ --------------------------------------- $$ | . . . . . O O X . . . X O O . . . . . | $$ | . . . O O O X X . . . X X O O . . . . | $$ | . . . O X X . . X . . . . X O O . O . | $$ | . . . O O X . . . , . . X X X , O . O | $$ | . . . O . W X . X X X X O O X X X O . | $$ | O O O O O X . O X O X X X O O O O X . | $$ | O X O X X . X O X O O X O O . O X X . | $$ | X X X X X X X O X O . O . O X O X O X | $$ | . . X O O X O X X O O . O X . X X O . | $$ | . X X O O O O O O X O . O X X , X O O | $$ | X X O X X X X . X X X O O O O X X X O | $$ | X O O X X X X X X . O O X X X X O O . | $$ | O . O O X O X O X O . O X . . X O . O | $$ | . O O X O O O O O O . O O X X O O . . | $$ | . . O X X . O O X O O X X . X O . . . | $$ | . O O X . X O X X X O O X . . X O O . | $$ | O O X X . X X X X O O X X X X X O . . | $$ | O X O . . . . X X X O O X O O O . . . | $$ | X X X X . . . . X O O . O . . . . . . | $$ ---------------------------------------[/go]

What do you think?

I'll give my thoughts tomorrow.

Bill Spight · Post by **Bill Spight** » Wed Apr 26, 2017 12:07 am

I think that Black will often have a ko threat in the top left corner, but there are some wrinkles.

Click Here To Show Diagram Code: [go]$$Bc Ko threat? $$ ------------------- $$ | . . . . . O O X . $$ | . 1 . O O O X X . $$ | . . . O X X . . X $$ | . 3 . O O X . . . $$ | . . . O 2 O X . X $$ | O O O O O X . O X $$ | O X O X X . X O X $$ | X X X X X X X O X $$ | . . X O O X O X X[/go]

Let Black play

as a ko threat. Now if

fills the ko, Black jumps to

. This looks a lot like seki.

However . . .

Click Here To Show Diagram Code: [go]$$Wcm4 Seki? $$ ------------------- $$ | . 2 . . . O O X . $$ | 6 X 1 O O O X X . $$ | 4 3 5 O X X . . X $$ | 9 X 8 O O X . . . $$ | 0 7 . O O O X . X $$ | O O O O O X . O X $$ | O X O X X . X O X $$ | X X X X X X X O X $$ | . . X O O X O X X[/go]

secures the White eye and threatens to take away the Black eye.

-

secure the Black eye in the corner. But now

threatens to make a second eye for White.

prevents that, but now White plays a throw-in at

.

Click Here To Show Diagram Code: [go]$$Wcm14 No Seki $$ ------------------- $$ | . X 3 . . O O X . $$ | X X O O O O X X . $$ | X O O O X X . . X $$ | 2 X X O O X . . . $$ | X O 1 O O O X . X $$ | O O O O O X . O X $$ | O X O X X . X O X $$ | X X X X X X X O X $$ | . . X O O X O X X[/go]

White wins the semeai, so that line does not work for Black.

Click Here To Show Diagram Code: [go]$$Bcm5 Seki? $$ ------------------- $$ | 3 2 1 7 . O O X . $$ | . X O O O O X X . $$ | 5 4 6 O X X . . X $$ | . X . O O X . . . $$ | . . . O O O X . X $$ | O O O O O X . O X $$ | O X O X X . X O X $$ | X X X X X X X O X $$ | . . X O O X O X X[/go]

Suppose that Black tries the hane,

.

throws in and then

-

prevent an eye for Black. But then

not only takes away White’s eye, it prevents the throw-in trick because of damezumari.

Click Here To Show Diagram Code: [go]$$Wcm12 Ko $$ ------------------- $$ | X . X X . O O X . $$ | . X O O O O X X . $$ | X O O O X X . . X $$ | 1 X 4 O O X . . . $$ | 2 3 . O O O X . X $$ | O O O O O X . O X $$ | O X O X X . X O X $$ | X X X X X X X O X $$ | . . X O O X O X X[/go]

takes ko.

But White has a slightly different throw-in trick, which makes ko. And White takes the ko first, so Black still has to find a ko threat.

But wait! There’s more! White can do better.

Click Here To Show Diagram Code: [go]$$Wcm8 Another ko $$ ------------------- $$ | X 3 X 1 . O O X . $$ | . X O O O O X X . $$ | . 2 . O X X . . X $$ | . X . O O X . . . $$ | . . . O O O X . X $$ | O O O O O X . O X $$ | O X O X X . X O X $$ | X X X X X X X O X $$ | . . X O O X O X X[/go]

makes ko and an eye at the same time.

In addition . . .

Click Here To Show Diagram Code: [go]$$Wc Ko threats $$ ------------------- $$ | X . X O . O O X . $$ | . X O O O O X X . $$ | 6 X . O X X 4 . X $$ | 5 X 2 O O X 3 . . $$ | . 1 . O O O X a X $$ | O O O O O X . O X $$ | O X O X X . X O X $$ | X X X X X X X O X $$ | . . X O O X O X X[/go]

White has three local threats.

threatens to make a second eye,

threatens to capture three Black stones for a second eye, and

threatens to take away Black’s eye. White has a threat at “a”, but it is not large enough to make up for letting Black live in the corner.

Does Black really have a ko threat in this corner? If White fills the 1/3 point ko, he trades it for a larger ko, but not one which Black takes first, one which White takes first, instead. Furthermore, White has three local ko threats. Black needs four extra threats just to keep up!

That is true. But this is a picnic ko for Black. White has to win it, or get sufficient compensation in exchange. Otherwise White takes a loss by winning the 1/3 point ko. But Black can afford to lose the ko, as long as she gets enough in exchange. And all Black needs to get enough is enough to afford to lose the original 1/3 point ko. In effect, Black is fighting the original, small ko while White is fighting the large ko. White may have ko threats that would be effective in the original ko fight but are too small to win the large ko. Also, Black may have losing ko threats that she could not afford to play against the original, small ko, but which she can afford to play against the large ko.

So whether this is a ko threat for the 1/3 point ko is a big maybe.

Bill Spight · Post by **Bill Spight** » Sun May 07, 2017 9:08 am

This is based upon the TrueTears vs. CrazyStone 5 kyu level game. I cleaned up the position a bit.

Click Here To Show Diagram Code: [go]$$B Black to play $$ -------------------------- $$ | . O . . . . . . . . . . . $$ | X X O O . . . O X X . X . $$ | . . X O O O O O O X . . . $$ | . . X X X X O X X , . . . $$ | . . . . . . X X . . X . . $$ | . . . . . . . . . . . . .[/go]

This is a standard Life and Death situation. I do not recall seeing it before, but it appears in Eba's Basic Life and Death Dictionary ( http://www.h-eba.com/heba/JITEN/jiten0-1.html ).

leaped out at me, but, OC, no play may necessarily leap out. I'll leave this as a problem for now, for those who wish to treat it as such.

Bill Spight · Post by **Bill Spight** » Sun May 07, 2017 12:32 pm

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

White has a 7 point room (marked) without a clear second eye. Such rooms are vulnerable.

Instead of starting with correct play, I am going to start with some mistakes, in order to explore this position.

Click Here To Show Diagram Code: [go]$$B Death in the hane? $$ -------------------------- $$ | . O . . . . 2 1 3 . . . . $$ | X X O O . 4 . O X X . X . $$ | . . X O O O O O O X . . . $$ | . . X X X X O X X , . . . $$ | . . . . . . X X . . X . . $$ | . . . . . . . . . . . . .[/go]

If Black plays hane-and-connect,

makes two eyes.

Click Here To Show Diagram Code: [go]$$B Death in the hane? (II) $$ -------------------------- $$ | . O 8 . 5 4 2 1 6 . . . . $$ | X X O O 7 3 a O X X . X . $$ | . . X O O O O O O X . . . $$ | . . X X X X O X X , . . . $$ | . . . . . . X X . . X . . $$ | . . . . . . . . . . . . .[/go]

prevents the eye at “a”.

threatens to make two eyes with an atari at 7.

-

prevent that , but then

makes seki.

Click Here To Show Diagram Code: [go]$$B Death in the hane? (III) $$ -------------------------- $$ | . O 5 7 8 4 2 1 . . . . . $$ | X X O O 6 3 . O X X . X . $$ | . . X O O O O O O X . . . $$ | . . X X X X O X X , . . . $$ | . . . . . . X X . . X . . $$ | . . . . . . . . . . . . .[/go]

@ 5

But

in this diagram kills. If

,

prevents a second eye. If

is at 7,

at 6 kills.

Click Here To Show Diagram Code: [go]$$B Death in the hane? (IV) $$ -------------------------- $$ | . O 5 6 . 7 2 1 . . . . . $$ | X X O O 4 3 . O X X . X . $$ | . . X O O O O O O X . . . $$ | . . X X X X O X X , . . . $$ | . . . . . . X X . . X . . $$ | . . . . . . . . . . . . .[/go]

If

as in this diagram,

-

kills. If

is at 7,

at 6 kills as above.

Click Here To Show Diagram Code: [go]$$B Death in the hane? (V) $$ -------------------------- $$ | . O 4 . . . 2 1 . . . . . $$ | X X O O . 3 . O X X . X . $$ | . . X O O O O O O X . . . $$ | . . X X X X O X X , . . . $$ | . . . . . . X X . . X . . $$ | . . . . . . . . . . . . .[/go]

in this diagram is an excellent play.

Click Here To Show Diagram Code: [go]$$B Death in the hane? (VI) $$ -------------------------- $$ | . O 4 . 6 . 2 1 5 . . . . $$ | X X O O . 3 . O X X . X . $$ | . . X O O O O O O X . . . $$ | . . X X X X O X X , . . . $$ | . . . . . . X X . . X . . $$ | . . . . . . . . . . . . .[/go]

If

,

makes two eyes.

Click Here To Show Diagram Code: [go]$$B Death in the hane? (VII) $$ -------------------------- $$ | . O 4 . 6 5 2 1 9 . . . . $$ | X X O O 8 3 7 O X X . X . $$ | . . X O O O O O O X . . . $$ | . . X X X X O X X , . . . $$ | . . . . . . X X . . X . . $$ | . . . . . . . . . . . . .[/go]

@ 2

If

in this diagram, White does best to atari with

. Then after

captures

,

captures 3 Black stones in a connect-and-die.

Click Here To Show Diagram Code: [go]$$B Death in the hane? (VIII) $$ -------------------------- $$ | . O 4 . 7 5 2 1 6 . . . . $$ | X X O O 8 3 . O X X . X . $$ | . . X O O O O O O X . . . $$ | . . X X X X O X X , . . . $$ | . . . . . . X X . . X . . $$ | . . . . . . . . . . . . .[/go]

If instead, White saves

,

threatens to kill. Then

only gets seki.

Click Here To Show Diagram Code: [go]$$B Death in the hane? (IX) $$ -------------------------- $$ | . O 4 9 8 5 2 1 6 . . . . $$ | X X O O 7 3 0 O X X . X . $$ | . . X O O O O O O X . . . $$ | . . X X X X O X X , . . . $$ | . . . . . . X X . . X . . $$ | . . . . . . . . . . . . .[/go]

But if Black tries

, White throws in with

and makes life with oshi-tsubushi.

Click Here To Show Diagram Code: [go]$$B Death in the hane? (X) $$ -------------------------- $$ | . O 4 . 5 a 2 1 6 . . . . $$ | X X O O b 3 . O X X . X . $$ | . . X O O O O O O X . . . $$ | . . X X X X O X X , . . . $$ | . . . . . . X X . . X . . $$ | . . . . . . . . . . . . .[/go]

After

,

prevents a second eye, but then

leaves “a” and “b” miai for seki.

More variations to come.

Edit: Made a silly oversight.

Corrected.
Edit 2: Added a couple of variations.

Bill Spight · Post by **Bill Spight** » Mon May 15, 2017 8:35 am

More variations, more mistakes.

Click Here To Show Diagram Code: [go]$$Bc Not exactly a hane $$ -------------------------- $$ | . W 1 2 . . 4 3 . . . . . $$ | X X O O . 5 . O X X . X . $$ | . . X O O O O O O X . . . $$ | . . X X X X O X X , . . . $$ | . . . . . . X X . . X . . $$ | . . . . . . . . . . . . .[/go]

is not a hane, because of the presence of

. And at first glance it does not look right. However, it was a vital point in the previous variations.

OC, White does not immediately capture

, as that leads to the easy kill shown.

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

prevents the hane, but now

looks promising. If

,

kills.

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

can make this ko. Note that if

at "a",

at 4 kills.

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

@

Curiously,

makes life because of the situation in the corner. If

connects at

,

at 9 captures 7 stones.

Click Here To Show Diagram Code: [go]$$Bc Curious life, cont. $$ -------------------------- $$ | X O 1 2 . O . O . . . . . $$ | X X O O O O . O X X . X . $$ | . X X O O O O O O X . . . $$ | . . X X X X O X X , . . . $$ | . . . . . . X X . . X . . $$ | . . . . . . . . . . . . .[/go]

Capturing the three Black stones gave White an eye. If

,

.

Click Here To Show Diagram Code: [go]$$Bc Ko, again $$ -------------------------- $$ | . W 1 . 5 4 . 2 . . . . . $$ | X X O O . 3 6 O X X . X . $$ | . . X O O O O O O X . . . $$ | . . X X X X O X X , . . . $$ | . . . . . . X X . . X . . $$ | . . . . . . . . . . . . .[/go]

So after

, Black can just make ko this way, with

.

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

Occasionally, seki might be right. Note that if

at 7,

at 6 kills.

Click Here To Show Diagram Code: [go]$$Bc Life $$ -------------------------- $$ | . W 1 a 5 6 3 4 . . . . . $$ | X X O O . 2 . O X X . X . $$ | . . X O O O O O O X . . . $$ | . . X X X X O X X , . . . $$ | . . . . . . X X . . X . . $$ | . . . . . . . . . . . . .[/go]

lives.

and

try to take away 2 eyes, but to no avail. If

at "a", White does not even have to capture the three stones right away, as we have seen above.

Bill Spight · Post by **Bill Spight** » Sat May 20, 2017 5:16 pm

The kill, at last!

Click Here To Show Diagram Code: [go]$$Bc Killer $$ -------------------------- $$ | . O . . . . 1 . . . . . . $$ | X X O O . a . O X X . X . $$ | . . X O O O O O O X . . . $$ | . . X X X X O X X , . . . $$ | . . . . . . X X . . X . . $$ | . . . . . . . . . . . . .[/go]

was the play the leapt out to me. “a” also kills.

Click Here To Show Diagram Code: [go]$$Bc One eye or no eye vs. eye $$ -------------------------- $$ | . O 4 . 5 . 1 2 . . . . . $$ | X X O O . 3 . O X X . X . $$ | . . X O O O O O O X . . . $$ | . . X X X X O X X , . . . $$ | . . . . . . X X . . X . . $$ | . . . . . . . . . . . . .[/go]

If

prevents

from connecting,

is the vital point. Now if

,

is the last vital point. If White captures the Black stones, Black can make a bulky five shape to kill. If not, Black can make an eye to win the semeai. If

at 5,

at 4 kills.

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

takes away one dame of

, but Black easily holds White to one eye.

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

takes away a dame this way.

and

escape, but then

makes two eyes.

is a mistake.

Click Here To Show Diagram Code: [go]$$Bcm5 Only one eye $$ -------------------------- $$ | . O 1 5 . O X B 2 . . . . $$ | X X O O 4 . O O X X . X . $$ | . . X O O O O O O X . . . $$ | . . X X X X O X X , . . . $$ | . . . . . . X X . . X . . $$ | . . . . . . . . . . . . .[/go]

@

takes away an eye, for the kill.

After

Black has a number of ways to kill. Here is another.

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

is a key point. After

prevents seki and kills with a bulky five. (Yes, there are only 4 stones inside now, but Black can almost fill with a bulky five.) If

at 7,

at 6.

Bill Spight · Post by **Bill Spight** » Sun May 21, 2017 8:55 am

Okigo Jizai again.

As I have said, I greatly admire Hattori Inshuku’s book about handicap go, Okigo Jizai. OC, go has advanced quite a bit in the past couple of centuries, but mostly in terms of opening strategy. These gains do not apply much, if at all, to high handicap games, so they remain just about as relevant today as they were back then.

The main thing I like about the book is Hattori’s spirit. It is mostly as though he shows plays that he would actually play or at least consider, himself. There is much more creativity in Okigo Jizai than in modern handicap go books, I think. There may be practical drawbacks to Hattori’s approach, in that he asks too much of Black, but he offers food for thought.

Another thing I like is Hattori shows how to make and use thickness. OC, in a high handicap game there are many paths to victory, but a pedestrian territory grab, even if successful, does not teach much of value in becoming a better go player. One complaint I often hear from kyu players is that they do not know how to use thickness. Hattori shows the way. OC, thickness is easier to make and use in high handicap games than in even games, but we start with baby steps.

I have already posted and commented in lifein19x19 on games from Okigo Jizai, but I propose to post some more in this forum, focusing on thickness and attack.

alphaville · Post by **alphaville** » Sun May 21, 2017 12:32 pm

Thank you for your earlier posts about Hattori's book as well - it opened my eyes to this part of the go history/culture I didn't know about. I also found his other book also available for free from the Waseda University online to be about handicap-go: http://senseis.xmp.net/?OnkoChishinGoroku
This second one seems to show lower handicap games. What is the difference in focus between these two books?

Bill Spight wrote:Okigo Jizai again.
As I have said, I greatly admire Hattori Inshuku’s book about handicap go, Okigo Jizai. OC, go has advanced quite a bit in the past couple of centuries, but mostly in terms of opening strategy. These gains do not apply much, if at all, to high handicap games, so they remain just about as relevant today as they were back then.

Bill Spight · Post by **Bill Spight** » Sun May 21, 2017 1:00 pm

alphaville wrote:Thank you for your earlier posts about Hattori's book as well - it opened my eyes to this part of the go history/culture I didn't know about. I also found his other book also available for free from the Waseda University online to be about handicap-go: http://senseis.xmp.net/?OnkoChishinGoroku
This second one seems to show lower handicap games. What is the difference in focus between these two books?

Thanks, alphaville.

I am not familiar with the other book. I'll check it out.

Bill Spight · Post by **Bill Spight** » Sun May 21, 2017 2:00 pm

Okigo Jizai does not show full games, but typically goes well into the middle game.

Here is a 6 stone game. Warning: Unless indicated, the comments are mine. Hattori did not make many comments.

Click Here To Show Diagram Code: [go]$$Wc Conservative opening for Black $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . X . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . 6 . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . X . . . . . , . . . . . B a . . | $$ | . . . . . . . . . . . . . . . . 3 . . | $$ | . . . . . . . . . . . . . . 5 . . . . | $$ | . . . . . . . . . . . . . . . . 1 . . | $$ | . . . . . . . . . . . . . . . 2 4 . . | $$ | . . . . . . . . . . . . b . . . . . . | $$ | . . . X . . . . . , . . . . . X . . . | $$ | . . . . . 0 . 9 . . . . 7 . 8 . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

White starts with the invasion cum large knight’s approach in the bottom right.

is aggressive, but after

,

strikes me as overconcentrated. Back when I was taking six stones I would surely have blocked at “a”, because the top right side is bigger. But then, OC, I might have to worry about those two stones,

and the stone on “a”, as they are so close to White’s strength. (Not that I worried about such things back then. I just lost a lot of stones.

) After

makes some territory and protects

against a pincer. I don’t like

either. “b” looks about right, to separate and attack White’s stones. But Black makes a solid position, while White must, perforce, stretch himself thin.

I do like. IMO White does not utilize the very large knight’s approach to the 4-4 enough in handicap games. Here it combines an approach with a 4 space extension.

shows some gumption, aiming to invade White’s thin bottom side.

Click Here To Show Diagram Code: [go]$$Wcm11 Leaning attack $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . X . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . X . . . . . , . . . . . X . . . | $$ | . . . a 9 . . . . . . . . . . . O . . | $$ | . . 1 3 4 0 . . . . . . . . O . . . . | $$ | . . 5 2 . . . . . . . . . . . . O . . | $$ | . . . 6 . . . . . . . . . . . X X . . | $$ | . 7 . . . . . . . . . . . . . . . . . | $$ | . . . X . . . . . , . . . . . X . . . | $$ | . . . . . X . W . 8 . . O . X . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

I like

, too, in general. In this case I think that it may be better at

, but I suppose that Hattori chose it to set up some lessons.

starts a leaning attack. Way back when, as a 3 dan in the U. S. the leaning attack was my secret weapon. Few players in the U. S. knew about it, and I got to use it to great effect.

Now, OC, everybody knows about leaning attacks.

leans against

to build up strength (thickness) in preparation for invading the bottom side, which Black does with

.

leaves me with the nagging feeling that it is so close that it becomes easy for White to sacrifice

. In effect, Black would be making territory from thickness. OTOH, that would give Black quite a lead in solid territory, a practical matter in a six stone game.

is interesting. White gets it in before sacrificing

; if White waits, Black may well cut at “a” instead. OC, this exchange weakens

if it tries to escape, so

pretty well predicts that White plans to sacrifice

.

Click Here To Show Diagram Code: [go]$$Wcm21 The sacrifice $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . X . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . X . . . . . , . . . . . X . . . | $$ | . . . . O . . . . . . . . . . . O . . | $$ | . . O O X X . . . . . . . . O . . . . | $$ | . . O X . . . . . . . . . . . . O . . | $$ | . . . X . . . . 0 9 . . . . . X X . . | $$ | . O . . . . . a 6 3 . . . . . . . . . | $$ | . . . X . . . . 7 2 1 5 . . . X . . . | $$ | . . . . . X . W . X 4 . O . X . . . . | $$ | . . . . . . . 8 . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

commences the sacrifice of

.

is an important move that I would have missed, even as a shodan. It is a point that each player wants in forming a base. I would have been too focused on

to take the value of L-03 into account.

is a good play. It avoids the temptation of playing atari at 30, which would be aji keshi.

You can make a case for playing

at “a”, but

claims more territory and puts some pressure on White.

Click Here To Show Diagram Code: [go]$$Wcm31 A good use of aji $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . X . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . 7 . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . X . . . . . , . . . . . X . . . | $$ | . . . . O . . . . . . . . . . . O . . | $$ | . . O O X X . . . . . . . . O . . . . | $$ | . . O X . . . . 5 . . . . . . . O . . | $$ | . . . X . . . 6 X O . . . . . X X . . | $$ | . O . . . . . . X O . . . . . . . . . | $$ | . . . X . . . 3 O X O O . . . X . . . | $$ | . . . . . X . O 2 X X . O . X . . . . | $$ | . . . . . . 4 X 1 . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

is tesuji. White sacrifices it to force

-

. Then

forces

, forming an empty triangle. White is satisfied with that kikashi, and shifts to the approach at

. White is still thin on the bottom side, but leaving thin positions behind is part of giving a six stone handicap.

This is a good lesson position. Where does Black play next? I am not sure that Hattori’s move is best, so this is not exactly a problem, but I will hide the next diagram if you want to take some time and think about it.

Click Here To Show Diagram Code: [go]$$Bcm38 Make territory while attacking $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . X . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . X . . . . . , . . . . . X . . . | $$ | . . . . O . . . . . . . . . . . O . . | $$ | . . O O X X . . . 3 . . 4 . O . . . . | $$ | . . O X . . . . O 1 . . . . . . O . . | $$ | . . . X . . . X X O . 2 . . . X X . . | $$ | . O . . . . . . X O . . . . . . . . . | $$ | . . . X . . . O O X O O . . . X . . . | $$ | . . . . . X . O X X X . O . X . . . . | $$ | . . . . . . X X O . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Perhaps

would be better at 39, stealing the eye and attacking both White groups instead of allowing them to join forces. However, this way Black makes territory while attacking.

I like Hattori’s next move for Black. Again, it may not be best, but I think it’s pretty cool. So I’ll leave it for tomorrow.

Bill Spight · Post by **Bill Spight** » Thu Jun 15, 2017 9:31 pm

Well, more than a day has passed, eh?

Among other things, I got caught up in the AlphaGo excitement.

I'll get back to the Okigo Jizai game later. This page is a placeholder.

Bill Spight · Post by **Bill Spight** » Tue Jun 20, 2017 9:33 am

Some reflections on AlphaGo vs. AlphaGo games

While I am hardly qualified to offer commentary on AlphaGo games, I do think that I may have some interesting things to say.

Much has been made of the fact that AlphaGo does not "think" like humans do, with some fans of AlphaGo claiming that humans are mistaken to think in terms of territory and points instead of the probability of winning -- which human cannot do, they add. I have criticized this point of view in various threads here, but looking at the AlphaGo vs. AlphaGo games, many plays seem quite different from current human play. Now, there is nothing new under the sun, and the New Fuseki of the early 20th century may be even more different from current human play. AlphaGo's style may reflect design decisions made by the AlphaGo team which may not have that much to do with its level of play. From what little I have seen of the latest incarnation of Zen, its play seems more "human", which probably has to do with its design. Within a few years other programs will reach the level of current AlphaGo. Will their play also look non-human?

In his recent interview with Hassabis ( https://www.youtube.com/watch?v=yav6LsOV3Ic ) Garry Kasparov quotes Picasso to the effect that computers are useless, they only give answers. Kasparov says that young chess players will tell him, Oh, I made a mistake, and when he asks why they say, the computer said so. The young players have no understanding of why the computer's suggested play is better (if, indeed, it is). When I saw that I thought, whatever the problems with the computer programs not giving explanations, their play can still be studied in a scientific spirit, like that of an ethologist studying animal behavior. It is in that scientific spirit that I undertake these reflections. What is AlphaGo doing when it plays itself? What hypotheses can I come up with about its behavior? Obviously, its characteristic play is related to its skill at go, but it is also related to its style. I certainly cannot say that any ideas I come up with have to do with better play, I leave that question to the pros. But I have already had some ideas that may be of interest.

moha · Post by **moha** » Tue Jun 20, 2017 11:11 am

Bill Spight wrote:Kasparov says that young chess players will tell him, Oh, I made a mistake, and when he asks why they say, the computer said so. The young players have no understanding of why the computer's suggested play is better

I recall some Master reviews, a few occasions where the reviewer reaches a conclusion like "alhough it seemed that (the human's) move was the correct direction and strategically advantageous, looking at the emerging sequence I see no errors by either player, and the outcome favors Master, so that move must have been a mistake afterall".

Is there always a reason why a move is bad, besides "the computer said so"?

Isn't human strategy just an imperfect substitute to minimaxing?

Kirby · Post by **Kirby** » Tue Jun 20, 2017 11:29 am

Bill Spight wrote: Garry Kasparov quotes Picasso to the effect that computers are useless, they only give answers.

I'm reminded of something that Lee Sedol said in an interview for The Surrounding Game documentary.

Lee Sedol wrote: You are not Picasso or Monet just because you imitate their paintings. Art is formed by putting your own color into something. A legendary player isn't remembered just for winning; They change the paradigm of the game. That's what I am striving to do too. But I have a long way to go.

Perhaps AlphaGo shouldn't be praised because of its winrate. Rather, we can judge whether AlphaGo changes the paradigm of go. We see pros adopting AlphaGo-style moves in their own games, especially in the opening. Whether or not this constitutes a paradigm-shift will have to stand the test of time. Fifty years from now, will we see a shift in paradigm in the way people think about go, due to AlphaGo?

Hopefully, such a paradigm-shift isn't something to the effect of, "this move is good because the computer says so"

Life In 19x19

This 'n' that

Re: This 'n' that

Re: This 'n' that

Re: This 'n' that

Re: This 'n' that

Re: This 'n' that

Re: This 'n' that

Re: This 'n' that

Re: This 'n' that

Re: This 'n' that

Re: This 'n' that

Re: This 'n' that

Re: This 'n' that

Re: This 'n' that

Re: This 'n' that

Re: This 'n' that