Hello, I went to this page on SL : Clamp and I saw this diagram :

Click Here To Show Diagram Code

[go]$$ B Black 1 is a Clamp
$$ . . . . . . . . . |
$$ . . . . . O . . . |
$$ . . . . . . . . . |
$$ . . . . . O . . . |
$$ . . . X . a . . . |
$$ . . . . X W 1 . . |
$$ . . . . . b . . . |
$$ ----------------[/go]

with this comment :

I wonder what happend for black if white choose 'b' for

Click Here To Show Diagram Code

[go]$$B
$$ . . . . . . . . . |
$$ . . . . . O . . . |
$$ . . . . . . . . . |
$$ . . . . . O a . . |
$$ . . . X 5 3 4 b . |
$$ . . . . X W 1 6 . |
$$ . . . . . 2 . . . |
$$ ----------------[/go]

what would black do after ? tried at a or b but can't find any good continuation for black...
or is that something wrong in my sequence ?

Any help welcome

_________________
Converting the book Shape UP! by Charles Matthews/Seong-June Kim
to the gobook format. last updated april 2015 - Index of shapes, p.211 / 216

a and then atari stone above to capture in ladder. If you don't have the ladder you can still fight and break white's shape. Usually it's good for black. Also 5 can make ko instead of connect if you don't like white keeping the points with this tesuji (black does get stronger on the outside in sente but it's a bit ugly):

Click Here To Show Diagram Code

[go]$$B
$$ . . . . . . . . . |
$$ . . . . . O . . . |
$$ . . . . . 9 0 . . |
$$ . . . . . O 7 . . |
$$ . . . X 5 3 4 8 . |
$$ . . . . X W 1 6 . |
$$ . . . . . 2 . . . |
$$ ----------------[/go]

Thanks Uberdude, I like the idea of the ladder.

_________________
Converting the book Shape UP! by Charles Matthews/Seong-June Kim
to the gobook format. last updated april 2015 - Index of shapes, p.211 / 216

You need to be careful about examples on SL. Remember, it is written by amateurs. I checked the page history and found out that this example arose from a question by a kyu player who asked if was a clamp. So it is.

But I would be very surprised if this diagram appeared in more than a handful of pro games, if any. Why? Because Black is too weak outside of the corner.

Click Here To Show Diagram Code

[go]$$ B Black 1 is a Clamp
$$ . . . . . . . . . . |
$$ . . . . . . O . . . |
$$ . . . . X . . . . . |
$$ X . . . . . O . . . |
$$ . . . . B . a . . . |
$$ . . . . . B W 1 . . |
$$ . . . . . . b . . . |
$$ ----------------[/go]

This is a much more likely position for the clamp. First, Black is strong enough outside not to worry about the safety of the stones, no matter how White answers the clamp. Second, Black has a stronger reply if White captures .

Not that you can't learn something by playing around with such examples. But you are much better off studying examples from pro games or books. Then you can trust that the play in the example is actually a good idea. (Unless the point is that it is a mistake, OC.) There are such examples on the SL page.

There are times when a player will make a second line clamp in the corner, even though he is weak outside. Here is an example.

Click Here To Show Diagram Code

[go]$$Wcm83 Yamamoto Genkichi (W) - Hayashi Tetsugen, 1803
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . X O O . . O . . . |
$$ | . . . X . . . . O . X O . O . . O . . |
$$ | . . X , X . . . . , X X O X X X O . . |
$$ | . . O . . . . . . . O O O X O X X X . |
$$ | . . . X O . . . . . . . X O O O O X . |
$$ | . . O O . . . . . . X X . . O X O O . |
$$ | . . . . . . . . . . . . X X O X . X . |
$$ | . . X . X . . . . . . . . O X . X . . |
$$ | . . . 2 . . . . . , . . . O X , . X . |
$$ | . . 1 . . . . . . . . . . O X . . X . |
$$ | . . . . . . . . . . . O X O X . X O . |
$$ | . . . . . . . . . . . . O X . . X O . |
$$ | . . . 9 . . . . . . . . O . X X O . . |
$$ | . 5 . . . . . . . . . . . O X O O . . |
$$ | . 3 4 X . . . . . , . . . . O , . . . |
$$ | . 6 8 . . X . O . . . . . . . O . . . |
$$ | . 7 . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

The clamp, , is played as a probe to leave aji in the corner. (OC, it threatens to live there if Black does not reply.) It is a good exercise to consider what the aji is if descends instead of connecting.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

Bill, thanks for the detailed response.

Ok thanks, good to know...


I do that too... I'm currently reading "So you want to play go, level 2" for 19 to 10 kyu and also "Fundamental Principles of Go, written by Yilun Yang" which is a bit harder for me... I feel that I understand what the book says, but when I do the exercices, I full wrong...



I was first thinking of this... but seems to be wrong

Click Here To Show Diagram Code

[go]Bcm90
$$ | . . . O . . . . . . .
$$ | . O . . . . . . . . .
$$ | . O X X . . . . . , .
$$ | 2 X 3 . . X . O . . .
$$ | . O 1 . . . . . . . .
$$ | . 4 5 . . . . . . . .
$$ -----------------------[/go]

I suppose black would more do that , which leads to connect and die for white...

Click Here To Show Diagram Code

[go]Bcm90
$$ | . . . O . . . . . . .
$$ | . O . . . . . . . . .
$$ | . O X X . . . . . , .
$$ | 2 X 3 . . X . O . . .
$$ | 5 O 1 . . . . . . . .
$$ | 6 4 7 . . . . . . . .
$$ -----------------------[/go]

so maybe more something like that... it seems that "a" is good neither for black nor for white...

Click Here To Show Diagram Code

[go]Bcm90
$$ | . . . O . . . . . . .
$$ | . O . . . . . . . . .
$$ | . O X X . . . . . , .
$$ | 2 X 3 . . X . O . . .
$$ | 4 O 1 . . . . . . . .
$$ | a 5 . . . . . . . . .
$$ -----------------------[/go]

_________________
Converting the book Shape UP! by Charles Matthews/Seong-June Kim
to the gobook format. last updated april 2015 - Index of shapes, p.211 / 216

@oca: When Bill says 'descend' he means this:

Click Here To Show Diagram Code

[go]B
$$ | . . . O . . . . . . .
$$ | . O . . . . . . . . .
$$ | . O X X . . . . . , .
$$ | 1 X . . . X . O . . .
$$ | . O . . . . . . . . .
$$ | . . . . . . . . . . .
$$ -----------------------[/go]

In go, when talking directions, down is "towards the nearest edge" and up is "towards the center", hence descend here means "stretch towards the nearest (left) edge".

oh.. ok... thanks, I will rotate my brain by 90° and try again then...

_________________
Converting the book Shape UP! by Charles Matthews/Seong-June Kim
to the gobook format. last updated april 2015 - Index of shapes, p.211 / 216

Hi oca,

Click Here To Show Diagram Code

[go]B
$$ | . . . O . . . . . . .
$$ | . O . . . . . . . . .
$$ | . O X X . . . . . , .
$$ | . X . . . X . O . . .
$$ | . W 1 . . . . . . . .
$$ | . . . . . . . . . . .
$$ -----------------------[/go]

In addition to what Herman said,
the you made is a hane (on ),
and a tiger's mouth, but not a descend.
A descend is a solid extension toward and close to an edge.

Situations like these are made for database searches which can show you whole board positions in which a pro might play such a clamp and what might happen, afterwards.

Using this:
https://badukmovies.com/pro_games/pattern_search

... shows the move played here by Xiao Zhenghao, 6p...
https://badukmovies.com/pro_games/43703 ... an?move=85

... and here
https://badukmovies.com/pro_games/3079- ... hi?move=69

... and in some other pro. games.

Thanks.

The second game is not really an example that fits the diagram on SL, because it has a Black stone on the 6-7 point.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

Indeed. I was posting at work and my aim was to punt the idea of using a database search to find pro games in which a position arises. Those games were examples picked in a hurry.

Yes. Thanks, again.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

Thanks, Herman.

First exercise.

Click Here To Show Diagram Code

[go]B
$$ | . . . O . . . . . . .
$$ | . O . . . . . . . . .
$$ | . O X X . . . . . , .
$$ | 1 X 2 . . X . O . . .
$$ | . O . . . . . . . . .
$$ | . . . . . . . . . . .
$$ -----------------------[/go]

What happens if White cuts?

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

@Charlie : thanks for the links, I didn't know that site.
@EdLee and Herman, thanks for your explanations, proper name is something important to me. I really like the proverb "If it has a name, know it" So I'm happy to add "descend" to my go vocabulary.

@Bill, thanks for the exercice,

I don't find any good continuation for white after that setup a ladder...

Click Here To Show Diagram Code

[go]B what for white after black 3...
$$ | . . . O . . . . . . .
$$ | . O . . . . . . . . .
$$ | . O X X . . . . . , .
$$ | 1 X 2 . . X . O . . .
$$ | . O 3 . . . . . . . .
$$ | . . . . . . . . . . .
$$ -----------------------[/go]

tryied

Click Here To Show Diagram Code

[go]B
$$ | . . . O . . . . . . .
$$ | . O . . . . . . . . .
$$ | . O X X . . . . . , .
$$ | 1 X 2 5 . X . O . . .
$$ | . O 3 4 . . . . . . .
$$ | . . 6 . . . . . . . .
$$ -----------------------[/go]

then at and that seems no good for white...
so I would not play ... correct ?

_________________
Converting the book Shape UP! by Charles Matthews/Seong-June Kim
to the gobook format. last updated april 2015 - Index of shapes, p.211 / 216

Well done!

But the cut is a threat. What play or plays threaten the cut and also threaten something else? Play around with that.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

Maybe in a ko fight where black plays somewhere else to win the ko and then I can play to concretise the threat

Click Here To Show Diagram Code

[go]$$W
$$ | . . . O . . . . . . .
$$ | . O . . . . . . . . .
$$ | . O X X . . . . . , .
$$ | X X 1 . . X . O . . .
$$ | 3 O . . . . . . . . .
$$ | . . . . . . . . . . .
$$ -----------------------[/go]

_________________
Converting the book Shape UP! by Charles Matthews/Seong-June Kim
to the gobook format. last updated april 2015 - Index of shapes, p.211 / 216

OK.

First question: What other ways are there of capturing the stones besides ?

Second question: What are local threats to make the cut that also threaten something else? (Really a repeat question, but answer the first question first. )

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

BadukMovies is a great site. Watch some of their free videos and, when you get to SDK (single-digit-kyu), subscribe. I think I gained five stones (9 kyu to 4 kyu) from their videos ... just keep your finger near the pause button. It often helps to think about a position on your own before letting the video explain the proper move.

(end of unsolicited plug)

This one seems to be better then my first try at "a"

Click Here To Show Diagram Code

[go]$$W
$$ | . . . O . . . . . . .
$$ | . O . . . . . . . . .
$$ | . O X X . . . . . , .
$$ | B B 1 . . X . O . . .
$$ | a O 3 . . . . . . . .
$$ | . . . . . . . . . . .
$$ -----------------------[/go]

tryied that but is a little annoying... but is still a threat I suppose.

Click Here To Show Diagram Code

[go]$$W
$$ | . . . O . . . . . . .
$$ | . O . . 6 . . . . . .
$$ | . O B B 5 . . . . , .
$$ | X X 1 3 4 X . O . . .
$$ | . O . . . . . . . . .
$$ | . . . . . . . . . . .
$$ -----------------------[/go]

or even that : [edit] but that goes a bit too far I think...[/edit]

Click Here To Show Diagram Code

[go]$$W
$$ | . . . O . . . . . . .
$$ | . O . . . . . . . . .
$$ | . O X X . . . . . , .
$$ | X X 1 4 3 X . Q . . .
$$ | . O 5 6 7 . . . . . .
$$ | . . . . . . . . . . .
$$ -----------------------[/go]

_________________
Converting the book Shape UP! by Charles Matthews/Seong-June Kim
to the gobook format. last updated april 2015 - Index of shapes, p.211 / 216

@oca: You're interpreting the order wrong. Bill is asking for threats before , not after.

Bill is asking "What are local threats to make the cut"

Here "the cut" is in your diagram. So he is asking you: Are there moves that threaten to make the cut possible, since you've already shown that playing it immediately fails (in post #14 of this thread).

The second part of his question: "that also threaten something else?" then means: Of those moves that would make the cut at possible, are there any that also contain a secondary threat, so that if black defends against the threat of the cut, white can do something nice elsewhere?