Life In 19x19

In a recent game, I played against a player who really loves to cut one-space jump from the third line. This caught me off guard, and I don't think I responded well. The first case is:

Click Here To Show Diagram Code

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

and so B1 becomes connected to the left side, significantly removing while influence.

Maybe the real mistake is that the pincer 2 is wrong -- I am not sure.


In the second example,

Click Here To Show Diagram Code

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

I live after entering 3-3, but white get a wall which I want to avoid initially by the one-space jump.


Any suggestion on what I should have done? Thanks.

Hi GoStudent,

In your first diagram, if you were White, and B forced you to get your ponnuki in sente, the result is very good for White.

When you jumped to , you allowed B to connect his and stones, as he did in your diagram. If you played at instead (kosumi) then B could not connect and -- homework: prove to your satisfaction this is true. This way, you could fight with B; this is another option for White.

and so B1 becomes connected to the left side, significantly removing while influence.

No. You have some big misunderstanding about influence, the situation, and the value of W's ponnuki in sente. This result was very good for .

Maybe the real mistake is that the pincer 2 is wrong -- I am not sure.

No, again. is too close to your powerful W wall. A pincer is a good idea. Exactly where to pincer is another question. Perhaps your is a bit too close to your own wall (same mistake as -- too close to thickness), but this is not a mistake at your level. The idea and direction of your pincer are OK. No problem.

In your second diagram, if you were , then was very strange. Instead, you should've ponnuki'd in sente (!!) -- play at yourself -- just like in your first diagram, and the result would've been very good for .

Instead of , of course W must reply to your atari by extending at . Both and were big mistakes -- both of you did not understand the value of the ponnuki.

__________
( Local time: Fri Dec 19, 2014. 11:53 am )

Thank you for the explanation!

I have one follow-up question. If black wants to be connected, is giving white the ponnuki the only choice? The following sequence doesn't work, for example.

Click Here To Show Diagram Code

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

gostudent wrote:The following sequence doesn't work, for example.

$$B
$$ -----------------
$$ . . . . . . . . .
$$ . . . 2 1 4 . . .
$$ . . X 3 O 5 X . .
$$ . . . . 6 . . . .
$$ . . . . O . . . .
$$ . . . . . . . . .
$$ . . . . . . . . .

Click Here To Show Diagram Code

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

It doesn't work because is completely wrong,
resulting in this disaster broken shape for Black:

Click Here To Show Diagram Code

[go]$$B
$$ -----------------
$$ . . . . . . . . .
$$ . . . O C O . . .
$$ . . X X O X X . .
$$ . . . . O . . . .
$$ . . . . O . . . .
$$ . . . . . . . . .
$$ . . . . . . . . .[/go]

( See also Toothpaste. )

Can you find the correct move (only move) for ?

EdLee wrote:

gostudent wrote:The following sequence doesn't work, for example.

$$B
$$ -----------------
$$ . . . . . . . . .
$$ . . . 2 1 4 . . .
$$ . . X 3 O 5 X . .
$$ . . . . 6 . . . .
$$ . . . . O . . . .
$$ . . . . . . . . .
$$ . . . . . . . . .

Click Here To Show Diagram Code

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

It doesn't work because is completely wrong,
resulting in this disaster broken shape for Black:

$$B
$$ -----------------
$$ . . . . . . . . .
$$ . . . O C O . . .
$$ . . X X O X X . .
$$ . . . . O . . . .
$$ . . . . O . . . .
$$ . . . . . . . . .
$$ . . . . . . . . .

Click Here To Show Diagram Code

[go]$$B
$$ -----------------
$$ . . . . . . . . .
$$ . . . O C O . . .
$$ . . X X O X X . .
$$ . . . . O . . . .
$$ . . . . O . . . .
$$ . . . . . . . . .
$$ . . . . . . . . .[/go]

( See also Toothpaste. )

Can you find the correct move (only move) for ?

Thanks. I think more about it, and a better sequence is:

Click Here To Show Diagram Code

[go]$$B
$$ -----------------
$$ . . . . . . . . .
$$ . . . 2 1 4 8 . .
$$ . . X 3 O 6 X c .
$$ . . . a 5 7 9 . .
$$ . . . . O . . . .
$$ . . . . . . . . .
$$ . . . . . . . . .[/go]

There is still a cut point at a. If black cannot handle the cut, B1 would still fail to connect the two black stones.

gostudent wrote:

$$B
$$ -----------------
$$ . . . . . . . . .
$$ . . . 2 1 4 8 . .
$$ . . X 3 O 6 B . .
$$ . . . a 5 7 9 . .
$$ . . . . W . . . .
$$ . . . . . . . . .

Click Here To Show Diagram Code

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

There is still a cut point at a. If black cannot handle the cut, B1 would still fail to connect the two black stones.

• Good, you found the correct atari, the only move.
• If the cut (a) is severe for Black, then B can fix it with , and give up connecting to , yes.
• Did you notice is now damaged -- broken shape for W ? (See post 4, again).
• Please see Toothpaste (post 4, again).

Click Here To Show Diagram Code

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

Click Here To Show Diagram Code

[go]$$B
$$ -----------------
$$ . . . . . . . . .
$$ . . . O X O O . .
$$ . . X X O O X . .
$$ . . . . X X . . .
$$ . . . X O . . . .
$$ . . . . . . . . .[/go]

Notice the broken shapes in the following two diagrams:

Click Here To Show Diagram Code

[go]$$B Broken shape for :wc:
$$ -----------------
$$ . . . . . . . . .
$$ . . . . . . . . .
$$ . . X X W W . . .
$$ . . . . X X . . .
$$ . . . X W . . . .
$$ . . . . . . . . .[/go]

Click Here To Show Diagram Code

[go]$$B Broken shape for :wc: (post 4, reversed colors)
$$ -----------------
$$ . . . . . . . . .
$$ . . . X . X . . .
$$ . . W W X W W . .
$$ . . . . X . . . .
$$ . . . . X . . . .
$$ . . . . . . . . .[/go]

Hi GoStudent, to recap:

If W does not want B to connect, W has kosumi (among other choices).
(Prove to your satisfaction this is true.)

Click Here To Show Diagram Code

[go]$$W
$$ ------------------
$$ . . . . . . . . .
$$ . . . . . . . . .
$$ . . X . O . X . .
$$ . . . . . 1 . . .
$$ . . . . . . . . .[/go]

Instead, if W chooses to jump to , AND attaches under,
now W has 2 choices (among other options):

• Let B connect.
• Capture , but as a result, suffers.

Click Here To Show Diagram Code

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

These are the local considerations.
For global consequences, we must look at the specific whole board situation.