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Posted: Mon Feb 24, 2014 7:52 am
by EdLee
If W ignores the ponnuki of :b4:, B has the very big move of :b6:, threatening the double atari (a):
Click Here To Show Diagram Code
[go]$$W
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 1 . . . . . . . . . . . . . X . . |
$$ | . X . . . . . . . . . . . . . . . X . |
$$ | X . X X . . . . . , . . . . . X X O . |
$$ | . X O O X X X . . . . . X X X O O O . |
$$ | 6 O a . O O . . . . . . . O O . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ -----------------------------------------[/go]

Re:

Posted: Mon Feb 24, 2014 7:54 am
by schawipp
EdLee wrote:If W deviates from the sequence and plays :w1:, then naturally B kills :wc: with :b2: and :b4: :
We compare the result on the left with the original sequence on the right:
on the left, W has already suffered a big loss because of :w1: :
Click Here To Show Diagram Code
[go]$$W
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 1 . . . . . . . . . . . . . X . . |
$$ | . X . . . . . . . . . . . . . . . X . |
$$ | X . X X . . . . . , . . . . . X X O . |
$$ | . X O O X X X . . . . . X X X O O O . |
$$ | . O . . O O . . . . . . . O O . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ -----------------------------------------[/go]
I think another problem is that w ended in sente at right side but in gote at left side. If w does not finish the sequence at e. g. A2, black can get a big "endgame" there e. g.:
Click Here To Show Diagram Code
[go]$$Bc W dies in the corner
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . . X . . |
$$ | . X . . . . . . . . . . . . . . . X . |
$$ | X . X X . . . . . , . . . . . X X O . |
$$ | . X O O X X X . . . . . X X X O O O . |
$$ | 1 O 4 3 O O 5 . . . . . . O O . . . . |
$$ | . . 2 . . . . . . . . . . . . . . . . |
$$ -----------------------------------------[/go]
Click Here To Show Diagram Code
[go]$$Bc This also looks rather unhealthy for w
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . . X . . |
$$ | . X . . . . . . . . . . . . . . . X . |
$$ | X . X X . . . . . , . . . . . X X O . |
$$ | . X O O X X X . . . . . X X X O O O . |
$$ | 1 O 2 . O O 4 5 . . . . . O O . . . . |
$$ | . . . 3 6 . 7 . . . . . . . . . . . . |
$$ -----------------------------------------[/go]
Edit: I see that in the meantime, EdLee has already written more or less the same ... ;-)

Re: 3.3 invasion joseki problem

Posted: Mon Feb 24, 2014 8:02 am
by lordish
Yeah thank you very much now it is much more clear to me.

Posted: Mon Feb 24, 2014 8:18 am
by EdLee
lordish wrote:Yeah thank you very much now it is much more clear to me.
Hi lordish, you're welcome. It's a good question,
but actually not so easy to explain at your stage. For example, you need a lot more experience
to see why the F17 :white: stone is very badly placed, too close to B's powerful wall.

Re: 3.3 invasion joseki problem

Posted: Mon Feb 24, 2014 8:21 am
by gowan
To the OP: You don't appreciate the weakness of the F17 stone and the significance of the loss in the corner.

The F17 move has several problems which can serve as guides for your future study and learning. First relates to the importance of sente versus gote. As was pointed out your sequence of moves allowing Black to capture the D18 stone results in White's invasion ending in gote. That means White has to make the last move in the corner, at B19. If White omits this move Black can play there and destabilize the white group. The standard joseki ends with Black making the last move so White has the initiative (sente) to start something elsewhere on the board. As for the White corner territory, after your sequence ending with B19, you (White) have about 8 points of territory. In the standard joseki sequence WHite gets about 10 points of territory. So your sequence loses White 2 points and also loses the initiative. Losing the initiative could possibly be OK if you gain enough from it. In this case you lost something, quite a difference.

Don't take these suggestions as criticism, we all started playing at or close to your level. You have a wonderful experience of learning ahead of you, enjoy! Go Seigen, arguably the greatest go player of the modern era, said that the greatest enjoyment is becoming one stone (rank) stronger. You can look forward to having this experience many many times!

Re: 3.3 invasion joseki problem

Posted: Mon Feb 24, 2014 8:54 am
by skydyr
Setting aside the actual punishment variant and looking at black's simplest reply:
Click Here To Show Diagram Code
[go]$$W
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 1 . . . . . . . . . . . . . . . . |
$$ | . X 2 . . . . . . . . . . . . . . . . |
$$ | . O X X . . . . . , . . . . . , . . . |
$$ | . 3 O O X X X . . . . . . . . . . . . |
$$ | . . . . O O . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ -----------------------------------------[/go]
If white then goes back to save the stone, then the result is the same as the normal joseki: Black is connected and white is alive in the corner. However, :w1: is plastered against black's wall and is for all intents and purposes already dead, AND black is leaving the joseki with sente, where he normally has to take gote. If white doesn't take :w3:, then later on, white has problems similar to what Edlee mentioned.

Posted: Mon Feb 24, 2014 4:46 pm
by EdLee
skydyr wrote:looking at black's simplest reply:
Click Here To Show Diagram Code
[go]$$W
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 1 . . . . . . . . . . . . . . . . |
$$ | . X 2 . . . . . . . . . . . . . . . . |
$$ | . O X X . . . . . , . . . . . , . . . |
$$ | . 3 O O X X X . . . . . . . . . . . . |
$$ | . . . . O O . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ -----------------------------------------[/go]
"simplest" here is maybe misleading. The connect :b2: above is another nonsense move, like :w1: itself.
Perhaps "simple-minded" ?

The actual simplest, correct, and only local reply for B is still the atari:
Click Here To Show Diagram Code
[go]$$W
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 1 . . . . . . . . . . . . . . . . |
$$ | . X . . . . . . . . . . . . . . . . . |
$$ | . O X X . . . . . , . . . . . , . . . |
$$ | . 2 O O X X X . . . . . . . . . . . . |
$$ | . . . . O O . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ -----------------------------------------[/go]
skydyr wrote:However, :w1: is ... for all intents and purposes already dead
Click Here To Show Diagram Code
[go]$$W
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 1 . . . . . . . . . . . . . . . . |
$$ | . X 2 . . . . . . . . . . . . . . . . |
$$ | . O X X . . . . . , . . . . . , . . . |
$$ | . 3 O O X X X . . . . . . . . . . . . |
$$ | . . . . O O . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ -----------------------------------------[/go]
Not at all. Far from it. We can say :w1: is badly placed and damaged.
But we cannot say it's "for all intents and purposes already dead."
It still has lots of aji. If the nearby conditions change in the future,
it can even come back and attack B's wall.

Re: 3.3 invasion joseki problem

Posted: Tue Feb 25, 2014 7:15 am
by lordish
Hi i was looking at avalanche joseki and i have a question what if he cuts at :w4: what approach should i take?
joseki .png
joseki .png (8.01 KiB) Viewed 3011 times
It seems perfectly fine to me, is this another joseki and if yeah what it is the name so i can have a look at it. Thanks in advance.

Ps:Tried to uploaded at sgf format but for some reason i kept taking the invalid game msg, is there something wrong with the site because i did all the steps from the how to post sgf thread.

Re: 3.3 invasion joseki problem

Posted: Tue Feb 25, 2014 7:20 am
by Uberdude
That's not the avalanche joseki, 2 is bad but not awful, 3 is awful and game losing move, 4 is good move and only move. 5 is black resign. Avalanche joseki is 2 at d15, then 3 and then 4 at 2. Move order is very important in Go.

Re: 3.3 invasion joseki problem

Posted: Tue Feb 25, 2014 7:31 am
by lordish
Uberdude wrote:That's not the avalanche joseki, 2 is bad but not awful, 3 is awful and game losing move, 4 is good move and only move. 5 is black resign. Avalanche joseki is 2 at d15, then 3 and then 4 at 2. Move order is very important in Go.
Yeah you are right i mixed up the move order sorry. On a funny note now that i looked up this position there are some pro games played with this continuation in a corner.

Re: 3.3 invasion joseki problem

Posted: Tue Feb 25, 2014 7:40 am
by Uberdude
I doubt there are pro games with these moves in this order. More likely this shape arose as a result of an ignored ko threat or ladder breaker on a shimari.

P.S. lordish based on your posts here I think you would do better to improve your basic instincts than study joseki. http://senseis.xmp.net/?BasicInstincts