Common Joseki Mistake(s) on Tygem

Loons · Post by **Loons** » Mon Mar 28, 2011 12:15 pm

I can perhaps explain - a reason I've often been told why we should play the small knight's move, not the large knight's is that the 3-3 invasion under the large knight's is better. So if black has already forfeited his ability to play the 3-3, the large knight's move gains ground as a choice.

mw42 · Post by **mw42** » Mon Mar 28, 2011 12:29 pm

Loons wrote:I can perhaps explain - a reason I've often been told why we should play the small knight's move, not the large knight's is that the 3-3 invasion under the large knight's is better. So if black has already forfeited his ability to play the 3-3, the large knight's move gains ground as a choice.

Yes, this is why the ogeima isn't usually played if white jumps out first. However, if white slides first than the ogeima becomes the proper extension from a two stone wall.

topazg · Post by **topazg** » Mon Mar 28, 2011 12:34 pm

@mw42: Regarding the long knight, I'd be slightly cautious about the following aji at 'a' - The security of the short knight would be worth eliminating that aji IMO:

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

mw42 · Post by **mw42** » Mon Mar 28, 2011 12:38 pm

Click Here To Show Diagram Code: [go]$$Bc $$ --------------------+ $$ . . . . . . . . . . | $$ . . . . . . 4 . . . | $$ . . 3 . 2 . . 5 . . | $$ , . . . . . 1 . . . | $$ . . . . 6 . . . . . | $$ . . . . . . . 7 . . | $$ . . . . . . . . . . | $$ . . . . . . . 8 . . | $$ . . . . . . . . . . | $$ , . . . . . , . . . |[/go]

Even with a keima I'd want to respond here.

By the way, just to clarify, I never said the keima would be bad in the situation just sub-optimal. Just as playing a two-space extension from a two stone wall would be sub-optimal, but it is still the correct play at times.

topazg · Post by **topazg** » Mon Mar 28, 2011 12:43 pm

Sure, but with the short knight, Black can fix happily with points:

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

with the long, he can't fix so easily, as this move still has a lot of aji:

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

aurik · Post by **aurik** » Mon Mar 28, 2011 12:52 pm

b9 looks bad there; given that 6 and possibly 8 lack a base, something that separates 8 from 6 would be in order?

topazg · Post by **topazg** » Mon Mar 28, 2011 12:55 pm

aurik wrote:b9 looks bad there; given that 6 and possibly 8 lack a base, something that separates 8 from 6 would be in order?

Sorry, I wasn't very clear. The illustration was more for later game aji, as opposed to immediate plays. I think :w8:

is overplay if played immediately.

mw42 · Post by **mw42** » Mon Mar 28, 2011 1:29 pm

That's fine. Just something to be aware of if you happen to play that shape. Blocking the corner at :b9:

is typically big yose anyway, so perhaps in that shape it's even larger. Still, the life of the black group is not in danger with your diagram.

topazg · Post by **topazg** » Mon Mar 28, 2011 1:33 pm

mw42 wrote:That's fine. Just something to be aware of if you happen to play that shape. Blocking the corner at is typically big yose anyway, so perhaps in that shape it's even larger. Still, the life of the black group is not in danger with your diagram.

With the short knight, :b9:

is normal, because of the peep aji if Black doesn't play it. Also, once :b9:

is played, the aji is completely gone from the whole corner.

With the long knight, there are some very complicated continuations with that last invasion, of which most seem to only almost work, though some I can't read out to my satisfaction - the fact none of those continuations exist with the short knight would have to make me have to really really want those extra 4 points to play long.

mw42 · Post by **mw42** » Mon Mar 28, 2011 1:38 pm

It seems to me that after :b9:

if

then white should die.

cloud · Post by **cloud** » Mon Mar 28, 2011 3:41 pm

mw42 wrote:By the way, just to clarify, I never said the keima would be bad in the situation just sub-optimal

I completely disagree with this statement. I guess what you are arguing is that the large knight's move is some sort of punishment against white for sliding first, but I don't think this is the case. If you look at topaz's diagram I agree that the aji is worse with the large knight's move. In my opinion, the reason the slide isn't played first normally is because it gives white two options:

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

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

There is no reason to give your opponent more options. Also, in reference to the first diagram, if it's reached from the normal joseki I am pretty sure there aren't pros out there that are like "Oh man now that the corner is like this I wish my extension was the large knight's move instead." Or else they would just play it in the first place.

mw42 · Post by **mw42** » Mon Mar 28, 2011 4:12 pm

You and I obviously look at the game differently. You look at this position and say "I'll play keima; it's joseki so it's good." Whereas I look at it and say "since I now have a two stone wall perhaps I should play the ogeima instead of the keima."

... I am pretty sure there aren't pros out there that are like "Oh man now that the corner is like this I wish my extension was the large knight's move instead."

Of course not; because there was a reason why they played keima in the first place. Often in a game I'll make a two-space extension then one of the stones gets kicked and now the shape is essentially a two-space extension from a two stone wall. No one would say the two-space extension was wrong, but they would recognize the shape as seeming a bit "cramped" or sub-optimal.

EDIT: Anyway, this is becoming very close to just an argument which is not really appropriate. So I'm going to refrain from any further comments in this thread about this silly matter. :clap:

(<-everyone reading this)

amnal · Post by **amnal** » Mon Mar 28, 2011 4:28 pm

mw42 wrote:You and I obviously look at the game differently. You look at this position and say "I'll play keima; it's joseki so it's good." Whereas I look at it and say "since I now have a two stone wall perhaps I should play the ogeima instead of the keima."

No! No!

I don't know whether you really think this is what cloud is saying, or if it's a more deliberate strawman, but either way you're misrepresenting him to make your own position look good. This is not a way to debate.

... I am pretty sure there aren't pros out there that are like "Oh man now that the corner is like this I wish my extension was the large knight's move instead."

Of course not; because there was a reason why they played keima in the first place. Often in a game I'll make a two-space extension then one of the stones gets kicked and now the shape is essentially a two-space extension from a two stone wall. No one would say the two-space extension was wrong, but they would recognize the shape as seeming a bit "cramped" or sub-optimal.

I'm still not convinced that the alternative shape is 'cramped' or suboptimal. Nor is cloud, apparently. I don't think it is enough to say 'in this shape, my move is the correct one', because that kind of reasoning is the kind where someone stronger inevitably comes along and says 'but what about this'

It seems to me that the large knights move takes a little more weakness at the cost of a little more aji. This seems a reasonable exchange to me.

EDIT: Anyway, this is becoming very close to just an argument which is not really appropriate. So I'm going to refrain from any further comments in this thread about this silly matter. (<-everyone reading this)

A debate about whether a move is good, or better than an alternative, is not silly. Indeed, as a continuation of the joseki 'mistake' which started the thread, it is a completely reasonable topic for discussion.

Shaddy · Post by **Shaddy** » Mon Mar 28, 2011 6:19 pm

topazg wrote:Sure, but with the short knight, Black can fix happily with points:

$$Bc
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . . . 4 9 . . |
$$ . . 3 . 2 . . 5 . . |
$$ , . . . . . 1 . . . |
$$ . . . . 6 . . . . . |
$$ . . . . . . . 7 . . |
$$ . . . . . . . . . . |
$$ . . . . . . . 8 . . |
$$ . . . . . . . . . . |
$$ , . . . . . , . . . |

Click Here To Show Diagram Code
[go]$$Bc $$ --------------------+ $$ . . . . . . . . . . | $$ . . . . . . 4 9 . . | $$ . . 3 . 2 . . 5 . . | $$ , . . . . . 1 . . . | $$ . . . . 6 . . . . . | $$ . . . . . . . 7 . . | $$ . . . . . . . . . . | $$ . . . . . . . 8 . . | $$ . . . . . . . . . . | $$ , . . . . . , . . . |[/go]

with the long, he can't fix so easily, as this move still has a lot of aji:

$$Bc
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . . . 4 9 . . |
$$ . . 3 . 2 . . 5 . . |
$$ , . . . . . 1 . . . |
$$ . . . . 6 . . 0 . . |
$$ . . . . . . . . . . |
$$ . . . . . . . 7 . . |
$$ . . . . . . . . . . |
$$ . . . . . . . 8 . . |
$$ , . . . . . , . . . |

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

I dislike black 9 in both diagrams and wish it were at p14. In this case the large knight's move makes extra points. Also, I was taught that if Black plays the large knight's move in response to a white approach to the corner, white should invade because if the normal joseki is played, Black is doing too well (by 2 points, or maybe slightly more). Just my two cents

daniel_the_smith · Post by **daniel_the_smith** » Mon Mar 28, 2011 7:12 pm

mw42 wrote:You and I obviously look at the game differently. ...

Yeah, 5 extra stones tends to cause that... :mrgreen:

cloud wrote:...in reference to the first diagram, if it's reached from the normal joseki I am pretty sure there aren't pros out there that are like "Oh man now that the corner is like this I wish my extension was the large knight's move instead." Or else they would just play it in the first place.

OK so to make an actual contribution: if I may be so bold, let me try to rephrase what I think cloud is saying:

1. A configuration of stones that is bad, is bad no matter how it was reached. (unstated assumption)
2. Pros will reach "good" positions much more than "bad" ones.
3. Pros reach this position with the short extension a lot more than with the long extension.
4. Therefore, it is very likely that pros consider the short extension to be better than the long one.

cloud wrote:In my opinion, the reason the slide isn't played first normally is because it gives white two options:

I think you meant "black" there?

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Common Joseki Mistake(s) on Tygem

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