Forming a base with little space

Alguien · #1

Dusk Eagle wrote:

Hey Alguien,

Just as a rule of thumb, try to avoid playing moves like the one below (of course there are exceptions). The extra power you give black is far greater than the extra stability such a stone provides. When you want to play an extension when there's a pincer, the correct location is one space farther from the pincer ('a').

Click Here To Show Diagram Code: [go]$$Wc $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . X O . a 1 2 . . . . . X . . . | $$ | . . . X X O . . . X . . . . . , . . . | $$ | . . X O X . . . . . . . . . . . . . . | $$ | . . O O . . . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . |[/go]

Once you said it it made much sense. I think my subconscious reasoning was: "it's sente, thus I have one more move after that.

However,

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

[/quote]

Should I expect 2 as response? (or, respond with 2 to such an approach).

And, if 2 is the expected response, which of these would be a natural sequence?

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

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

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

TegaiS · #2

Looks like white shouldn't bother to save those F16, F17 stones. And probably on the last diagram white can play :w3:

right away without :w1:

,

exhange.

Joaz Banbeck · #3

Alguien wrote:

...
And, if 2 is the expected response, which of these would be a natural sequence?

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

...

B would probably not play 4 as shown above.

Remember, he played this:

Click Here To Show Diagram Code: [go]$$Wc $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . X O . . . . . . . . . X . . . | $$ | . . . X . Q . . . X . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . |[/go]

...because he did not want you to do this:

Click Here To Show Diagram Code: [go]$$Wc $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . X O . . . . . . . . . X . . . | $$ | . . . X . Y . . . X . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . |[/go]

So apply that same reasoning, and you get this:

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

You have lots of extra stones early in the game, so think power and influence, not territory. If he gets a point or two around K19, you need not care because your influence is worth more.

Alguien · #4

Joaz Banbeck wrote:

So apply that same reasoning, and you get this:

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

Just "Stretch from a kosumi-tsuke". ffs I feel quite stupid right now...

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

However this result seems so bad that maybe even trying to create that base was wrong and I should have gone for something like...

not being cut in the first place.

But once I am...

Sac the stones and use the aji? Even if that's the correct answer, I don't even know how to start.

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

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

(I'll try all possibilities, just like those 6d bots)

Uberdude · #5

Btw, I'm inclined to disagree with Joaz and think black should block on the 2nd line rather than the 4th line tiger mouth. I want black to turn the top side into territory by attacking white (and split from left group), not let white live on the top. Also white really ought to capture the stone at c16 to strengthen that group and weaken the black corner before even considering moving out with the top stones, so black should be looking to take sente to play there. The double hane is not so bad, what is worse is the subsequent greedy play immediately trying to save both sides thus giving black a perfect splitting attack, rather than taking a more flexible approach of trades.

Uberdude · #6

To expand on what sort of trades I mean:

White should take the stone (obviously black extending it in the game was crap)

Click Here To Show Diagram Code: [go]$$Wc $$ ------------------------- $$ | . . . . . . . . . . . . $$ | . . . . . . . . . . . . $$ | . b 2 . X O . . . . . . $$ | . a 1 X X O . . . X . . $$ | . 3 X O X . . . . . . . $$ | . . O O . . . . . . . . $$ | . . . . . . . . . . . . $$ | . . . . . . . . . . . .[/go]

Now maybe you are thinking "Oh noes, that was gote! Now he can attack/kill my stop stones. Boo hoo." But the corner is very big, black should atari at a (or maybe descend at b but it's rather wimpish and pathetic). So white is quite happy if this happens:

Click Here To Show Diagram Code: [go]$$Bcm4 $$ ------------------------- $$ | . . . . . . . . . . . . $$ | . . . . . . . . . . . . $$ | . 2 X . X O . . . . . . $$ | . . O X X O . 1 . X . . $$ | . O . O X . . . . . . . $$ | . . O O . . . . . . . . $$ | . . . . . . . . . . . . $$ | . . . . . . . . . . . .[/go]

Now let's say black finishes off the 2 stones. You get a nice big atari in the corner, and as a super magic bonus you have some sort of connection or at least huge yose at a for later so black didn't really get much at all!

Click Here To Show Diagram Code: [go]$$Bcm6 $$ ------------------------- $$ | . . . . . . . . . . . . $$ | . . 2 . a . . . . . . . $$ | . O X . X O . . . . . . $$ | . . O X X O . X . X . . $$ | . O . O X 1 . . . . . . $$ | . . O O . . . . . . . . $$ | . . . . . . . . . . . . $$ | . . . . . . . . . . . .[/go]

So let's say black descends in the corner (he could instead block and then there is a big ko fight). White is then happy to have got the corner move in sente to make that group have good eyeshape and can tenuki. At some point white can consider pulling out the two stones. But the big difference now is that after those moves in the corner not only is white running with a weak group, but the black corner is not alive either so there are chances to counter attack. Just for example say black goes tally ho attacking and neglects his corner. The hane at e18 his a key point that makes black have a false eye in the corner, builds white's eyeshape and aims at jumping to a next, whilst black's group gently dies. Because white has played those moves on the left making his group strong and black's weaker, white is now saving his top stones with attitude, instead of just making a useless heavy group.

Click Here To Show Diagram Code: [go]$$Bcm6 $$ ------------------------- $$ | . . . . . . . . . . . . $$ | . . 1 7 6 . 8 . . . . . $$ | . O X . X O . . a . . . $$ | . . O X X O . X . X . . $$ | . O . O X . 2 . . . . . $$ | . . O O . . . . 3 . . . $$ | . . . . . . 4 . . . . . $$ | . . . . . . . . 5 . . .[/go]

Bill Spight · #7

As Uberdude says, the play for White is to take the Black stone on the left.

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

The

stones are so weak, White should consider sacrificing them.

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

looks pretty bad, but once it is played, how to respond to :b2:

?

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

is the play to make eye shape.

Click Here To Show Diagram Code: [go]$$Bcm4 $$ --------------------------------------- $$ | . . . . . . . . 8 6 7 . . . . . . . . | $$ | . . . 5 4 . O . 2 3 9 . . . . . . . . | $$ | . . X . X O . O X . . . . . . X . . . | $$ | . X O X X O 0 1 . X . . . . . , . . . | $$ | . O . O X . . . . . . . . . . . . . . | $$ | . . O O . . . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . |[/go]

White can live like this, but it is very good for Black.

Lamp · #8

Assuming you wish to sacrifice the 2 stones, what might be the best way to do so? Is the following reasonable?

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

Bill Spight · #9

Lamp wrote:

Assuming you wish to sacrifice the 2 stones, what might be the best way to do so? Is the following reasonable?

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

I think that perhaps this is a case where you don't know where to play, and it is best to wait. After all, it is possible that White will end up saving the :wc:

stones. That said, "a" looks pretty good.

Dusk Eagle · **#10**

My suggestion was more of a general comment on the shape, where you don't want to play a diagonal contact play against an opponents fourth-line stone. I would've captured the stone like Uberdude suggested, but I didn't feel confident enough to assert that was the only way to play.

Also, like Bill said, the below sequence is aji-keshi; it's better just to wait and see what you can do with those stones.

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

Uberdude · **#11**

This thread has rather gone back to a general review, so to answer the thread title: it's hard, so probably best not to try. ;-)

mitsun · **#12**

However, if you need to live or make a base in a confined space, there is still the question of the best technique.

Here is a nice problem along those lines which I came across recently. B has just played the marked move, preventing W from making a base in the corner. How does W settle this group?

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

Uberdude · **#13**

This attachment is one idea. White lives in sente but black gets thick. Seeing as white already got 1 tenuki, presumably to c10, getting another is nice for a fast-paced opening (and these 2 tenukis can be used to mitigate the power of black's wall). Black can't cut 1 at 3, or white at 9, black cuts at g17, white cuts at j17 and the ladder is good for white.

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

Or to avoid getting sealed in, simply jumping along to the 2nd line is nice as black's attachment doesn't work so well as white lives in sente with more points than before and black is not so thick and the g15 cut aji remains:

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

So black pushes white down low and build a big wall.

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

This variation works nicely for white with a 4-4 at the top right:

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

mitsun · **#14**

Uberdude wrote:

This attachment is one idea. White lives in sente but black gets thick.

Correct answer, nice analysis. The book actually gives a slightly different move order, presumably to guard against B playing first at :w7:

below. The main point is that W lives in sente, which he uses to defend at (a), negating the B thickness.

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

Without the contact play, W has no good way to settle this group. For example, here is a simple sequence with an inadequate result -- B blocks off the side and W has no time to defend against (a).

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

Uberdude · **#15**

If white wants to make the invasion at a less severe (but still a nice point) so she can tenuki somewhere else then c10 could be played at d10. This would work nicely if there is a black 4-4 you could approach in the lower left corner to make a nice wave shape.

Forming a base with little space

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