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7k destroys 6k, was it joseki?
http://www.lifein19x19.com/viewtopic.php?f=4&t=3315		 Page 1 of 1
Author:  Phelan [ Sat Feb 26, 2011 12:38 pm ]
Post subject:  7k destroys 6k, was it joseki?
I was white, and was completely destroyed in this game, first during corner exchanges, and then during the endgame.

I'm especially interested in the lower left corner, since I had never seen that line of play before. Is B3 joseki? Did I pick the wrong replies? I felt very outplayed in that corner, without feeling I had done something particularly wrong.
Author:  mw42 [ Sat Feb 26, 2011 12:48 pm ]
Post subject:  Re: 7k destroys 6k, was it joseki?
In my opinion, you tried to punish him too severely. There is a simple way to punish him in the lower-left.
Author:  jts [ Sat Feb 26, 2011 3:37 pm ]
Post subject:  Re: 7k destroys 6k, was it joseki?
mw42 wrote:
There is a simple way to punish him in the lower-left.


Excellent use of tewari, very intelligible.
Author:  blade90 [ Sat Feb 26, 2011 3:40 pm ]
Post subject:  Re: 7k destroys 6k, was it joseki?
B3 is not really joseki but a trick play.
Surprising is that a lot of players stronger then 10k fall for it, while weaker players defend proberly.
mw42 already showed the normal reply to the moves, however there is also this variation your opponent can go into:

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


Black will play at 'a' next depending on the situation.
Author:  Shaddy [ Sat Feb 26, 2011 3:48 pm ]
Post subject:  Re: 7k destroys 6k, was it joseki?
It's an oddness of trick-plays that they tend to work on a narrow interval of ranks- For example, I couldn't get anyone to fall for the 19-point trick play until I hit 1d, but then 1 and 2d players would go for it pretty much every time, and 3ds generally know it.
Author:  illluck [ Sat Feb 26, 2011 6:04 pm ]
Post subject:  Re: 7k destroys 6k, was it joseki?
I'm not ashamed to admit that my first instinct (and probably what I'd have played in game) was exactly the same as phelan's move in game. Finding the refutation isn't hard (I saw it pretty much immediately after abandoning the attempt to read out the variations from my first instinct), but the hard part is in finding out that the first instinct doesn't work (I still can't read it out).
Author:  oso [ Sat Feb 26, 2011 8:44 pm ]
Post subject:  Re: 7k destroys 6k, was it joseki?
Unable to really comment fully. Still, I enjoyed playing the game over!
Author:  mitsun [ Mon Feb 28, 2011 4:57 pm ]
Post subject:  Re: 7k destroys 6k, was it joseki?
The result in the lower left corner left W with a perfectly playable position, with enough thickness to compensate for the B corner territory. However, both players made serious mistakes in the subsequent play on the bottom, so let me make a few comments there.

B move 35 is much too dangerous, asking for trouble. B needs to be very wary of the W thickness to the left. A one space extension (N3) is as far as B should go here. W took advantage of the opportunity to start a fight by invading immediately at M3 (good!).

B move 41 is a tactical mistake. B must cut here, then atari on top after W captures the M2 stone. Various continuations are possible, all better for B than the game result. After W connects at move 42, B has two weak groups under severe attack, both of which are too large to sacrifice comfortably.

W move 52 is almost a pass. The hane at H3 would leave B without sufficient eye space to live. It seems likely that at least one of the two big B groups would die.

W move 60 is the wrong direction, attacking from the strong side, forcing B to make strength facing the weak W group to the left. Much better would be to strengthen the weaker group, perhaps simply by jumping to somewhere around M8. As the weak B group runs, W should have plenty of opportunity to make territory naturally on the right side, while maintaining center strength and keeping up the attack.

W moves 70 and 72 were complacent. If B ignores the peep and plays N9 or N8, it looks like W gets captured. In addition, the peep is aji-keshi, allowing B to defend a dangerous cutting point. W cannot afford to let B cut here, so despite the bad shape, move 42 must be the bent triangle at N8. B could push through and escape, but W would still be in the game.
Author:  Aphelion [ Mon Feb 28, 2011 5:40 pm ]
Post subject:  Re: 7k destroys 6k, was it joseki?
blade90 wrote:
B3 is not really joseki but a trick play.
Surprising is that a lot of players stronger then 10k fall for it, while weaker players defend proberly.
mw42 already showed the normal reply to the moves, however there is also this variation your opponent can go into:

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


Black will play at 'a' next depending on the situation.


I'm sorry but that is horrifically bad for Black. The 5-6 exchange especially stands out. If 5 is played, Black must ko.
Author:  blade90 [ Tue Mar 01, 2011 1:31 pm ]
Post subject:  Re: 7k destroys 6k, was it joseki?
Aphelion wrote:
I'm sorry but that is horrifically bad for Black. The 5-6 exchange especially stands out. If 5 is played, Black must ko.

Yo're right it is bad for black at least locally, that is way it is a trick play and not used by pros ;-)
But if white knows how to reply then the result would be accepable for black because of the whole board position.
If you look at the diagram below:
Click Here To Show Diagram Code
[go]$$B Black can play at a,b or c next
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . X , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . b c . . . . . , . . . . . , . . . |
$$ | . . a . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . 5 . . . . . . . . . . . . . . . . . |
$$ | . 7 3 O . . . . . , . . . . . O . . . |
$$ | 6 1 2 8 . O . . . X . . . . . . . . . |
$$ | . 4 . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Well I'm still very weak but I guess it is ok for black now, not good but not really bad either.
Feel free to correct me if I'm wrong so I can learn where my mistake is :study:
Ah by the way what ko do you mean?
Author:  Shaddy [ Tue Mar 01, 2011 1:54 pm ]
Post subject:  Re: 7k destroys 6k, was it joseki?
Part of this is a transposition of a joseki which is played regularly by pros (well, it's not a joseki. It's a coping method for black when his stone is in trouble.) So you can't call it a trick. However, I disagree with Aph- his is a ko Black can't afford. I think this is the only way after W 4:
Click Here To Show Diagram Code
[go]$$B
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . X . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . 5 1 O . . . . . , . . . . . O . . . |
$$ | . 3 2 6 . O . . . X . . . . . . . . . |
$$ | . 4 . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


It often appears in positions like this: here, white 4 is probably bad.
Author:  Aphelion [ Tue Mar 01, 2011 2:04 pm ]
Post subject:  Re: 7k destroys 6k, was it joseki?
Shaddy, I'm not insinuating that the ko is good for black in anyway. However, the only consistent way after 5 locally is to ko (so the problem is Black 5). The 5-6 exchange shown in Blade's first diagram is too horrible, I think.
Author:  Shaddy [ Tue Mar 01, 2011 2:25 pm ]
Post subject:  Re: 7k destroys 6k, was it joseki?
oh, ok. I misunderstood you- yeah, you're right.
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