Life In 19x19

@Cloud

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[go]$$Bc
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . . . b . . . |
$$ . . 3 . 2 . . . . . |
$$ , . . . . . 1 . . . |
$$ . . . . a . . . . . |
$$ . . . . . . c d . . |
$$ . . . . e . . . . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ , . . . . . , . . . |[/go]

When white jumps out at (a), then (c) and (d) are the most common moves here. Typically you see (c) which aims at the cap at (e) and development along the side. However, depending on the situation, (d) is also played which, as in the joseki B(d), aims at securing a large corner with (b).

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[go]$$Bc
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . . . Q . . . |
$$ . . 3 . 2 . . Y . . |
$$ , . . . . . 1 . . . |
$$ . . . . a . . . . . |
$$ . . . . . . c d . . |
$$ . . . . e . . f . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ , . . . . . , . . . |[/go]

If the marked exchange is played before white jumps out at (a), then (c) is certainly still possible, but (d) feels a bit small with the possibility of securing a large corner being gone. However (f) is more attractive because the corner is now closed to white (he cannot invade) and it develops more territory along the side.

I'm really surprised to meet so much resistance to this idea. It looks like a basic "3-space extension from a two stone wall" idea.

@Dusk Eagle

Thank you for the game records. I see nothing wrong with (in the original diagram) in those games as it seems to be "pushing black toward thickness."

FWIW, and not to be disagreeable with anyone, but having stated fairly definitely that for White to allow Black the pincer and to pull back is a mistake in the past, I have found it not to be the case. Both from mid-high dan players and also from numerous professional games, this is a common way of preventing Black from kicking - something White may want if he has a position on the top and is trying to build big strength to attack.

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[go]$$B Variation 1
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . . . 6 . . . |
$$ . . 3 . 2 . . . . . |
$$ , a . . . . 1 . . . |
$$ . . . . 4 . . . . . |
$$ . . . . . . . 5 . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |[/go]

Click Here To Show Diagram Code

[go]$$B Variation 2
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . . . 6 . . . |
$$ b . 3 . 2 . . . . . |
$$ , a . . . . 1 . . . |
$$ . . . . 4 . . . . . |
$$ . . . . . . 5 . . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |[/go]

In variation 1, dailyjoseki reports as more common than "a" in professional games, albeit normally with a White stone on top (which is an important consideration before playing it seems - odd, that used to be my favourite joseki in an open corner and open sides when I was around the 8-10k mark).

In variation 2, dailyjoseki reports as considerably less common than "a" in professional games, although it's still the second most common and again normally has a White stone on top at "b". Interestingly, my recollection is that this is a common sequence when White starts out with an approach and then pulls back to "b" (or vice-versa, when White wedges in the middle of the orthodox and gets approached from the shimari, and responds here instead of the two space jump), expecting the invasion. Black often uses this to overconcentrate (see my latest Malkovich game against magicwand in the lower right):

Click Here To Show Diagram Code

[go]$$B Variation 2
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . 8 . . . . . |
$$ W . 3 . 2 7 . . . . |
$$ , 6 . . . . 1 . . . |
$$ . . . . 4 . . . . . |
$$ . . . . . . 5 . . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |[/go]

So to say the slide is definitely aji-keshi seems to be rather overstating it. I suspect, as with all corner joseki choices, it's dependent on the rest of the board (or, in this case, the top edge at least). Certainly seems eminently playable with some purpose behind it

topazg wrote:albeit normally with a White stone on top

Where is the white stone at the top? In 'b' from your second diagram? I think this is a fundamentally different position, and that it is not fair to apply the same logic to it. The slide is clearly fine here, but none of the reasons for this make much sense to me if the white stone is not there.

Actually... It makes a big difference whether that stone is high or low, topazg-- you might want to check again.

Low: http://dailyjoseki.com/browse/bwpwxibxgwvsbva (the slide is more common-- this surprises me!)

High: http://dailyjoseki.com/browse/bwpwxibxgwvsbuz (the shoulder hit is most common, as I expect)

EDIT: nvm, sorry, I completely misread your post.

topazg wrote:FWIW, and not to be disagreeable with anyone, but having stated fairly definitely that for White to allow Black the pincer and to pull back is a mistake in the past, I have found it not to be the case. Both from mid-high dan players and also from numerous professional games, this is a common way of preventing Black from kicking - something White may want if he has a position on the top and is trying to build big strength to attack.

$$B Variation 1
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . . . 6 . . . |
$$ . . 3 . 2 . . . . . |
$$ , a . . . . 1 . . . |
$$ . . . . 4 . . . . . |
$$ . . . . . . . 5 . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |

Click Here To Show Diagram Code

[go]$$B Variation 1
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . . . 6 . . . |
$$ . . 3 . 2 . . . . . |
$$ , a . . . . 1 . . . |
$$ . . . . 4 . . . . . |
$$ . . . . . . . 5 . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |[/go]

$$B Variation 2
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . . . 6 . . . |
$$ b . 3 . 2 . . . . . |
$$ , a . . . . 1 . . . |
$$ . . . . 4 . . . . . |
$$ . . . . . . 5 . . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |

Click Here To Show Diagram Code

[go]$$B Variation 2
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . . . 6 . . . |
$$ b . 3 . 2 . . . . . |
$$ , a . . . . 1 . . . |
$$ . . . . 4 . . . . . |
$$ . . . . . . 5 . . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |[/go]

In variation 1, dailyjoseki reports as more common than "a" in professional games, albeit normally with a White stone on top (which is an important consideration before playing it seems - odd, that used to be my favourite joseki in an open corner and open sides when I was around the 8-10k mark).

In variation 2, dailyjoseki reports as considerably less common than "a" in professional games, although it's still the second most common and again normally has a White stone on top at "b". Interestingly, my recollection is that this is a common sequence when White starts out with an approach and then pulls back to "b" (or vice-versa, when White wedges in the middle of the orthodox and gets approached from the shimari, and responds here instead of the two space jump), expecting the invasion. Black often uses this to overconcentrate (see my latest Malkovich game against magicwand in the lower right):

$$B Variation 2
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . 8 . . . . . |
$$ W . 3 . 2 7 . . . . |
$$ , 6 . . . . 1 . . . |
$$ . . . . 4 . . . . . |
$$ . . . . . . 5 . . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |

Click Here To Show Diagram Code

[go]$$B Variation 2
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . 8 . . . . . |
$$ W . 3 . 2 7 . . . . |
$$ , 6 . . . . 1 . . . |
$$ . . . . 4 . . . . . |
$$ . . . . . . 5 . . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |[/go]

So to say the slide is definitely aji-keshi seems to be rather overstating it. I suspect, as with all corner joseki choices, it's dependent on the rest of the board (or, in this case, the top edge at least). Certainly seems eminently playable with some purpose behind it

This is not correct. It appears that dailyjoseki.com is using too tight a pattern area. This is only more common when a stone is very close on the top side. If a more realistic pattern area is used, you will find that the shoulder hit is about three times as common even when 5 is low.

I believe the slide is more common when black has a low stone because white is trying to make black feel a bit cramped, whereas sliding when black has a high stone helps black settle his position easier. For this same reason, when black has already played low and white slides, black prefers to play the diagonal move at , let white into the corner, and then extend along the side.

Click Here To Show Diagram Code

[go]$$B
$$ --------------------+
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . O . . . |
$$ . X . O . X . O . . 2 . . |
$$ . . . , 1 . . . . X . . . |
$$ . . . . . . . O . . . . . |
$$ . . . . . . . . . . X . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . |
$$ . . . . . . . . . . 3 . . |
$$ . . . . . . . . . , . . . |[/go]

(if you're really interested in this pattern, see http://www.koreatimes.co.kr/www/news/art/2010/08/152_18262.html and http://www.koreatimes.co.kr/www/news/art/2010/08/152_18918.html)

nagano wrote:This is not correct. It appears that dailyjoseki.com is using too tight a pattern area. This is only more common when a stone is very close on the top side. If a more realistic pattern area is used, you will find that the shoulder hit is about three times as common even when 5 is low.

Yeah, I think my website should process this position a little differently.

daniel_the_smith wrote:

nagano wrote:This is not correct. It appears that dailyjoseki.com is using too tight a pattern area. This is only more common when a stone is very close on the top side. If a more realistic pattern area is used, you will find that the shoulder hit is about three times as common even when 5 is low.

Yeah, I think my website should process this position a little differently.

How do you define the pattern area? I haven't used your site much, so it's not clear to me.

nagano wrote:This is not correct. It appears that dailyjoseki.com is using too tight a pattern area. This is only more common when a stone is very close on the top side. If a more realistic pattern area is used, you will find that the shoulder hit is about three times as common even when 5 is low.

Perhaps, but I'm not sure if you are missing my point or not. The purpose was to illustrate that looking for severe punishments is probably not possible, because the shape is so close to usefully playable in general terms that it can't be that outright bad. The fact that, with different local stones, the slide is effectively kikashi and fine, means that in the worst case it is surely likely to be non-severe aji keshi?

It would be interesting to see the amount of professional games where the slide got played and where the 3-3 invasion got played (and where neither got played) to see how much aji is actually being keshied (sorry John!).

nagano wrote:How do you define the pattern area? I haven't used your site much, so it's not clear to me.

Short answer: I have an algorithm (if I explained it, this wouldn't be a short answer!) that tries to be intelligent about the pattern size. It is not optimal (I believe that it handles invasion sequences poorly, for example), but it seems to work quite well most of the time. Since making it I've realized that there's (probably) an objectively correct way to do this, but I haven't had time to investigate it.

@mw42

I'm not saying the large knight's move is bad. I'm just responding to you saying the small knight's move is bad, which is incorrect. It is a common joseki which pros play frequently as stated by me, topaz, etc.

As for the slide, in handicap games (where I'm white), and often in even games I play it all the time because I don't want to give my opponent the option of kicking. Especially when I don't care about the corner I think it's a useful move. I hardly think it's fair to classify it as aji-keshi.

cloud wrote:@mw42

I'm not saying the large knight's move is bad. I'm just responding to you saying the small knight's move is bad, which is incorrect. It is a common joseki which pros play frequently as stated by me, topaz, etc.

As for the slide, in handicap games (where I'm white), and often in even games I play it all the time because I don't want to give my opponent the option of kicking. Especially when I don't care about the corner I think it's a useful move. I hardly think it's fair to classify it as aji-keshi.

I'd love to see an example in a pro game, cloud.

Here is a link from Daily Joseki. Small knight's move:

http://dailyjoseki.com/browse/bwpwxibxgwvsbvawyfbxl

This position was reached 229 times.

Your move (Large knight's move):

http://dailyjoseki.com/browse/bwpwxibxgwvsbufwyfbxl

This position was reached 20 times.

Cloud, I don't mean to sound rude, but did you read my posts? My whole argument for the large knight's move being superior to the knight's move is based on the exchange before .

I don't understand your argument. Just because the order changes doesn't mean that the result you would get after making the small knight's move is no longer joseki. There is no reason to reject the move just because the slide occurred first.