A: Pincer, when is this the best move, and specifically is it better near the sides and corners or can it be valuable in the center as well?

B: Striking at the waist of the keima, this seems to be less valuable toward the edge if you're striking down toward the edge, I understand some of what this is about, but not entirely. When is the best time, best place, and why?

B: Think about it this way; when you cut the keima "at the waist" (I still don't understand why it's the waist, btw), you take a loose connection and turn it into a standard crosscut. If you understand why crosscutting on the second line is usually a bad idea, you should understand why a keima from the third line to the second line usually can't be cut.

In the center:


Against the side:


(The difference, if it's not obvious to you already, is that at "a" is a move that strengthens W in the first two diagrams, but it captures the cutting stone in the second two.)

A: I can't give you a confident answer, but I want to record what I think so that when someone more awesome explains, I learn from my mistakes.

Pincers are attacking moves. Their advantage is that they prevent the opponent from making an extension along the side. Their disadvantage is that they are self-separating, that you're automatically creating two groups.

Therefore, they are generally played when you are strong in the surrounding area, when you have stones that can support a continued attack.

Example:

Click Here To Show Diagram Code

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

Black chooses to pincer because he has the supporting stones on both sides, which means that he can make a severe attack against white's approach. Of course there are many possible continuations, I've shown one that exemplifies the kind of severe attack that black can make.

Click Here To Show Diagram Code

[go]$$W Bad pincer
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . X . . . . . . . . . . . . . |
$$ | . . . O . . . . . X . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . W . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 8 . 7 . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 4 . 3 . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X , 1 . . 2 . , . . . . . W . . . |
$$ | . 6 5 . a . . . . 9 . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

In this position, white's approach is supported by the marked white stones. If black pincers, white can make a counter-attack by leaning on black's stones on the left, then counter-pincering with

In this position, it would have been far more appropriate for black to play a move at a with , simply taking corner territory and building a solid group.


When pincering from 4-4, it is generally possible for the opponent to simply take the corner. For that reason, pincers from 4-4 are generally good if outside influence is what you want. Since the presence of stones that would support an attack will generally also help in building a framework, the above general rule holds in this case as well.

As for pincering in the center: It is possible, but not really called a pincer generally.

Click Here To Show Diagram Code

[go]$$W Ear move
$$ . . . . . . . . . . .
$$ . . . . . . . . . . .
$$ . . . X . 1 . 2 . . .
$$ . . . . . . . . . . .
$$ . . . . . . . . . . .[/go]

The move at can be a sever attack against depending on the surrounding position. I've heard this be called an "ear move", or "hitting someone on the ears".

Since this is an attacking move again, you can remember the general rule:

Pincer when you are strong in the surrounding area

That's three questions.

_________________
Patience, grasshopper.

@daal keep thinking about it...

_________________
Occupy Babel!

Pincers should normally be prepared, but there is no hard and fast rule. Experience is a good teacher. Play a lot of pincers to develop your judgement about them.

Here is a game with a number of pincers and counter pincers. I have added a few comments.

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

Visualize whirled peas.

Everything with love. Stay safe.

thanks for the detailed explanations and for posting that dosaku game it's pretty entertaining and interesting.