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#185 EdLee vs. The Intrepid: The Swords http://www.lifein19x19.com/viewtopic.php?f=37&t=7220 |
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Author: | EdLee [ Sat Dec 08, 2012 3:45 am ] |
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Take your time. I'm not home, either, and won't be for a few more months! |
Author: | The Intrepid [ Tue Dec 11, 2012 5:41 pm ] |
Post subject: | Re: #185 EdLee vs. The Intrepid: The Swords |
Comments to follow shortly. |
Author: | EdLee [ Tue Dec 11, 2012 5:56 pm ] |
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Interesting, not expected. Locally, I thought the press could stay ahead of W:
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Author: | EdLee [ Tue Dec 11, 2012 6:36 pm ] |
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Author: | The Intrepid [ Tue Dec 11, 2012 8:15 pm ] |
Post subject: | Re: #185 EdLee vs. The Intrepid: The Swords |
Comments regarding : I had a wide array of moves to choose from. The general idea is to reduce White's potential on the right side of the board and, at the same time, gain points where they are easier to get--the top or the top-right corner. To this effect, professionals preferred "a" or "b," usually playing "a" and then "b" in conjunction. Lee Chang-ho played "a" then "c."
It was also possible to tenuki, leaving the Black stone at the top-right alone for the time being. The best places to tenuki would be "d"--which expands the bottom moyo and fights for influence in the center--and "e" which would take a large corner and threaten to reduce White's moyo on the right from underneath the White stones. In addition to all the above options, Lee Sedol played "f" in one game, taking the corner right away. The exact situation on the board was this:
As to the move in the game, the knight's jump is a relatively new move. Out of the 40 games in the database I could find, 30 of them happened in the last 10 years. Let's compare and contrast this move with similar moves:
The problem with (B) is that the marked stone is on the 3rd line, leaving Black insufficient room to do anything substantial against the corner. As a result, either Black gets insufficient territory in the corner to offset White's gains (after White "a") or else Black's influence turns out to be insufficient to offset White's territory in the corner and on the top (after White "b"):
As for the (A) vs. (C), the two moves are similar in many ways. In both cases, Black separates White's two stones, seeking to apply pressure against one or the other. As for the differences:
Black's first two stones cannot be easily disconnected. These two stones apply greater pressure against the corner than toward . is not connected very well to the original two stones, however, enabling White to play "a" in various situations.
By contrast, here all the three Black stones work well together and apply more pressure toward . However, the original two stones are apply less force against the corner and aren't as well connected with one another. I cannot really offer too much insight beyond this, however. I never played (A) before. Similarly, my knowledge about (C) is limited, given that I either invade the corner or approach the corner from the other side when faced with a close-low pincer. That said, as I was familiarizing myself with (A) and (C), I came to realize that these josekis are best when Black has a stone in the bottom-right corner (and absent White stones there). For example, Black cannot complain about the following result (So Yokoku vs. O Meien (b), 2004):
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Author: | skydyr [ Tue Dec 11, 2012 8:19 pm ] |
Post subject: | Re: #185 EdLee vs. The Intrepid: The Swords |
@The Intrepid I noticed you discussed a lot of options, but not your last move. What lead you to choose it? |
Author: | The Intrepid [ Tue Dec 11, 2012 8:20 pm ] |
Post subject: | Re: #185 EdLee vs. The Intrepid: The Swords |
EdLee made his move quickly. Interesting. Either he anticipated or else he played his move by instinct. He had various moves to choose from, however. In any case, what he played is natural and good. I'll take a little bit of time to consider a few options I now have but I will likely play the following move, expecting the indicated sequence:
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Author: | The Intrepid [ Tue Dec 11, 2012 8:21 pm ] |
Post subject: | Re: #185 EdLee vs. The Intrepid: The Swords |
skydyr wrote: @The Intrepid I noticed you discussed a lot of options, but not your last move. What lead you to choose it? Oh, I'm getting there. I'll comment on and even on . Bear with me. |
Author: | skydyr [ Tue Dec 11, 2012 8:23 pm ] |
Post subject: | Re: #185 EdLee vs. The Intrepid: The Swords |
observers The Intrepid wrote: In addition to all the above options, Lee Sedol played "f" in one game, taking the corner right away. The exact situation on the board was this:
I think black is fine with white building influence on the right, because the marked black stones are low, so black has good reducing moves to use against white later on. Does anyone else have an opinion? |
Author: | The Intrepid [ Tue Dec 11, 2012 8:49 pm ] |
Post subject: | Re: #185 EdLee vs. The Intrepid: The Swords |
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Author: | EdLee [ Tue Dec 11, 2012 9:10 pm ] |
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Watching the Samsung Cup, round 2, Gu Li v. Lee Sedol; with Mr. Kim's commentary. |
Author: | The Intrepid [ Tue Dec 11, 2012 9:12 pm ] |
Post subject: | Re: #185 EdLee vs. The Intrepid: The Swords |
Comments regarding : As I mentioned in one of my previous posts, EdLee's is unusual by profesisonal standards. There are only two games I could find where pros played "a." By contrast there are 13 games with , where Black usually responded at :
I am not too familiar with these sort of situations, so the fine details escape me. Ultimately, the issue probably is that the corner is too easy to invade after "a." Black can easily play "b." Another noteworthy observation is that Black can eventually hope to play "c" or "d" with comfort when is at "a." In any case, the difference should not be larger than a few points (probably)--not devastating at the amateur level. What is also noteworthy is that the sample size of games is rather small. A measure of caution is, therefore, advisable when drawing conclusions. |
Author: | The Intrepid [ Tue Dec 11, 2012 9:34 pm ] |
Post subject: | Re: #185 EdLee vs. The Intrepid: The Swords |
Comments regarding The choices available to me were to tenuki or to play one of the following:
I decided to hold off on choosing between "c" or "d" until the situation below clarifies a bit. I believe both "a" and "b" are possible in the given situation. With "b," my intention is to reduce White's territory on the side in sente, obtain a safe group there, ideally limit White's potential on top, and then proceed with cultivating my territory on the bottom. Specifically, the following would be a sequence very much to my liking:
Next, "e" or "f" for Black would be huge. could also be the following:
Of course, these are hardly the only options for either side. I forgot to say that if played "a" instead of "b" (as in the game) I am not sure if I would be able to play correctly afterward. The following has to be playable, but the marked stones are too close for my liking:
Essentially, I worry that, if I am not careful, my stones on the right would be unable to live locally and, consequently, would become the object of White's attack. |
Author: | EdLee [ Tue Dec 11, 2012 10:04 pm ] |
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If hane instead of extend, here's one variation where B makes good shape with a series of sente moves:
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Author: | The Intrepid [ Tue Dec 11, 2012 10:09 pm ] |
Post subject: | Re: #185 EdLee vs. The Intrepid: The Swords |
This move of EdLee's is surprising to me. Why be so submissive? The result is that I reduced his moyo on the right to the 3rd line essentially for free. Now I'll need to think a bit whether to play in the top right corner or just tenuki. |
Author: | The Intrepid [ Tue Dec 11, 2012 11:24 pm ] |
Post subject: | Re: #185 EdLee vs. The Intrepid: The Swords |
Comments regarding In addition to the move in the game, EdLee could have considered the following:
The move seeks to reduce White's territory to the 3rd line. Next, if I get to play on the bottom at "d," I'll be building 6th line territory, while White's area would remain largely confined to the 3rd line.
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Author: | The Intrepid [ Tue Dec 11, 2012 11:51 pm ] |
Post subject: | Re: #185 EdLee vs. The Intrepid: The Swords |
Comments regarding : On the one hand, EdLee's move seems to lack ambition, willingly accepting 3rd line territory. On the other hand, if he played on the 4th line and I cut, I could hope to get important shape points at and in sente:
The possible responses I am thinking about currently are these:
"a" would seek to further reduce White's territory, but I am not sure if it is sente. "b" would improve Black's shape at the cost of eliminating some of the aji in White's shape. I need to make sure, however, that White actually has to respond at P16. "c" is tempting, but the following variation gives me pause:
"d" is the safe way to reinforce the Black stones. However, perhaps I should first exchange other moves before playing here. "e" and "f" are moves that would seek to prevent White from expanding on the top side. However, before playing these moves, I first need to understand why either of them is sente, which apparently they are. "g" seeks to register a profit from the reduction of White's moyo on the right. However, if played immediately, my stones on the right could fall under attack. "h" is similar to "g" but aims to threaten White's territory. This is a huge point, but "g" seems bigger right now, especially since I already extended to the left on move 3:
Therefore, I have yet another tough choice to make. I think I'll need to sleep on this one. I've looked up some more pro games with similar positions as in the top right. It turn out EdLee's move occurs frequently. I was too quick to criticize it. Now I need to understand the difference between the position in the game and the one I used to search for pro games:
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Author: | The Intrepid [ Thu Dec 13, 2012 4:08 am ] |
Post subject: | Re: #185 EdLee vs. The Intrepid: The Swords |
First of all, mental note to self: when confronted with a close-low pincer, double approach the corner or invade the corner directly--don't jump. Otherwise, this happens. I get "influence" which, in fact, is little more than a heavy group of stones one step away from the grave. Anyway, I managed to convince myself that is actually sente. This is important because my group will be much stronger after the following exchange:
If EdLee ignores my move, this could follow:
Alternatively, I could also consider this:
In any case, after either variation, my group on the right side should become strong enough to warrant an attack against White's top-right corner. Incidentally, some professionals in a similar situation didn't care about reinforcing their group further and just attacked the corner straight away. For example, in Kobayashi Koichi vs. Yo Kaei, 2008, play continued as follows:
It's amazing to me that it's possible to play like this. |
Author: | EdLee [ Fri Dec 14, 2012 12:22 am ] |
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If hane, B probably can get another sente move?
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Author: | The Intrepid [ Fri Dec 14, 2012 1:56 am ] |
Post subject: | Re: #185 EdLee vs. The Intrepid: The Swords |
OK, now comes the hard part. Do I tenuki to take territory at "a"; do I launch an attack against the top-right corner at "b" or "c"; do I play "d" in hopes that White replies passively at "c"; do I jump out from my central group to one of the "e" intersections; or do I try to further strengthen my group at "f," aiming at "c" or "g"?
Incidentally, in comparison to the usual shape here, the game structure has two main differences. "i" is normally bad aji for Black and "j" is bad aji for White.
Another very interesting idea is to play this , hoping to obtain the indicated sequence:
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