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BQM131
Path: BigQuestionMark · Prev: BQM130 · Next: BQM132
Difficulty: Advanced Keywords: MiddleGame, Strategy, Question
Alex Weldon: Okay... so this is an abstraction of a position I had in a KGS game today.
Obviously, the position in the lower center was not quite this neat, but this is basically what it boiled down to. The Black group is alive, and there is another small, squished, but alive Black group in the lower left... they are separated by a string of White stones (linked up to a live group, so they're in no danger). So, essentially, the bottom and lower left corner are played out, but the rest of the board is wide open. There's a White hoshi in the top left. I'm assuming that, since White has developped a wall facing Black's marked hoshi in the course of attacking the Black lower side group, the most urgent thing for White to do is approach it somehow. But how? I considered all of a through g, but none seemed right. Now, in retrospect, I'm thinking b or c, but in the actual game I tried something fancy that didn't quite work as planned. Is this as complicated an issue as I think, or am I overlooking the one, right move? SnotNose: The White approach has got to be from the direction of b or c, the idea being "use your thickness to attack" or "push your opponent toward your thickness." White a would hardly be worth anything. I think White wants to play c, aiming to uproot Black's corner.
SnotNose: Isn't this making territory while attacking? White a later would force Black out toward the center.
Bill: Dieter: There is a scent of joseki approach here, while a proverb like play away from thickness is more likely to bring good ideas, which may coincide with a joseki. Applying the principle here, ...
Hence, ...
... one must ponder
Velobici: Alex Weldon: Good commentary from all of you, and more or less what I thought. For the record, what I played was the very low approach e, which might be thought of as hamete in this position. Black responded correctly, though, so he lived in the corner, while the position I got on the right was lower than it would have been if I'd played honestly. However, he then tried too hard to press me low and get out to the middle, which started a battle that ended up with me cutting him off and (much later) killing him in the middle. SnotNose: Agree with Alex that comments are good and interesting. They point to a general question I've had for months now: how does one decide whether to approach a stone (whether in the corner, or pincering an approach) on the 3-rd line or 4-th (here we've even considered the 2-nd line too!!!). I appreciate that this question is nearly unanswerable in general. What is interesting is that, even in a specific case (above), there is room for disagreement. That is, 3-rd, 4-th (and maybe 2-nd) line approaches seem all seem playable, at least for shodan (or higher?) level players. So, a more refined question is: are there circumstances where 3-rd vs 4-th (vs. 2-nd) is only a matter of taste, each leading to different strategies and games but all okay? How does one determine whether the height of the approach matters and when it is just style?
Velobici: When pincering, either one is trying to extert the maximum of pressure is exterted by playing on the same line as the pincered stone. This depends directly upon whether or not the pincered stone is on the same line as the corner stone.
SnotNose: I came across a problem in 501OpeningProblems last night that is identical in spirit to this BQM, though it differs in (unimportant) details (exact position of stones, orientation). It is number 270, page 135. In the problem, it is Black to play and defend, rather than White to attack. The answer is the equivalent to c in the diagram at the top of this page (small knight's enclosure). The answer says "If White were to play here, the Black stones would be in trouble because of White's thickness." This is strong support for c. I would be surprised if 9 out of 10 dan level players didn't play c without much thought. Sure, one can ponder other approaches, but it is hard to imagine one's hand not flying to c in an actual game. It is also hard to criticize this move, in this context. What happens after White c is a separate question. Some new ideas occured to me last night.
SnotNose: Black is very likely to play
SnotNose:
SnotNose: Black can play a and then move out toward the center. Black's stones would be without a base and come under attack. Or, Black can play b.
SnotNose: If Black now plays a, we get a similar result as above (White thickness & developing moyo. If Black plays b, White will get the corner and Black might have some prospects on the right side. I think this (Black b, White a) would be the worst result for White.
SnotNose: Black has follow-up moves at a or b. White has made an investment too large for the profit and Black dodged the attack. So, I conclude that the
SnotNose: All in all, it is hard to see how White goes wrong after c. Most likely, she will get thickness and a moyo, while Black lives in the corner in gote. Charles My idea.
In such positions it can be good to play at
SnotNose: Isn't this SelfIndulgentReading? No way Black plays a. A hane on top of Andrew Grant: But the hanes look bad as well. White will most likely crosscut and start a fight. With White's wall so close, it's hard to see Black doing well. Fighting in front of your opponent's strength is dreadful. SnotNose: a has been argued to be bad. I'm not convinced hane is bad (showing some variations would be helpful). There is also Black d. Why would Black play a heavy move like a in the presence of White thickness? I think a lighter, sabaki-seeking move (like c, b, or maybe d) might be better.
SnotNose: For what it's worth, here's a hane and cross-cut example. Is this bad for Black? Or, more to the point, worse than the descent below
Bill: The problem with
Andrew Grant: White will play 1 and 3, leaving the marked stone in a silly place. If 2 at a, White will be happy to fight the ko as he already has a profit on the lower edge.
SnotNose: This is better for White than if Black had played the descent? (This is the question we're addressing. And what about the jump to d suggested above? Question is: is the descent Charles suggested the best Black can do? It is so obviously bad and heavy, I would hesitate to play it. I'd have to be really convinced something lighter is not better here.) Ok, change the marked stone to something else.
SnotNose: Torn between this Andrew Grant: Difficult, but I think I'd play a now as White.
Black 2 and 4 aren't as good as they might look, as a and b are miai for White.
SnotNose: So, perhaps, Black protects b before playing
Anyway, we could go on with this for a while. I'm just as unlikely to play the heavy descent move (circled point) after White's attachment (
Bill: After the crosscut, I think that Black can put up a strong resistance with A couple of points:
Something else to consider.
Suppose this happens. Are the
SnotNose: Thanks Charles. The admission of some degree of uncertainty/ambiguity is what I was after. (See, not so clear cut afterall!) The suggestion of To sum up, if I may, the knight's move (my suggestion) is the simple path to a satisfactory result. Charles' attachment idea is one way to complexity, which is sometimes the only way to victory (or is otherwise advantageous given relative strengths of players). Black's best reply to the attachment is likely not to initiate the out-of-order wrong-way-block to the 3-3 invasion joseki--but I'm not sure this has been demonstrated. (I'm waiting to be convinced otherwise.) All in all, a very interesting BQM debate.
Dieter: Isn't this the best way for Black to treat the crosscut ? Velobici: The diagrams have dealth with low approach (c), inside attachment (f) and 3-3 invasion (g). We dont have a single diagram here showing a continuation based upon b. Have we discussed and ruled out the high approach (b in the top most diagram)? If so, could someone explain why b has been ruled out? (Looking for some dan players to humor a 10 kyu here and help him improve. Dont worry I wont ask about a, d, and e. ;) SnotNose: I'll take a stab. I'm not 100% confident in my thinking but here goes...b is a move for outside influence. The same objective can be obtained better with c, as shown in the diagrams above. Compare the following two diagrams.
SnotNose: White has a large gap between
SnotNose: This way, the gap between
SnotNose: A general point: I usually consider the most standard approach move first (c). If that seems to work well, I might think about other moves, but they have to really be clear improvements for me to play them. Circumstances where I'd play b are when a Black cap of c (a Black play two spaces to the left of c) is too good for Black (Black would have to have good prospects on the bottom for this case) or when I do not want to face a Black pincer. Neither situation applies here. I consider Charles' attachment idea typically when taking territory in the corner or outside are miai (usually this is a move I consider for invasions of moyos). This isn't so clearly the case here either, though it does still seem playable. On balance, I strongly favor the most common move (c) unless circumstances strongly dictate otherwise. Playing a less common move when circumstances don't warrant it invites trouble. That is, there is a larger probability I will regret not having played the most common move. So, the most common move is not always best but there is a reason it is most common. It is quite frequently best and one should have good reason to play differently. Put another way, I'm less inclined to feel I have to justify c over b than the other way around. Someone would have to convince me b is better to knock the idea of c out of my head. Showing one or two favorable variations is not enough to convince. It really has to be a very good argument, typically based on more than just exploration of variations. The reason is that I cannot read all variations with every move (who can?) so need to base thinking on higher level concepts. Reading is only part of the answer. Ultimately one has to support moves with some other idea or else it is not possible to remember when they are good or bad. Another point of view
This seems the ordinary idea for me after
If Black plays this way after
Bill: Black can secure the corner with
As for who gets sente here on the edge, I'm not clear.
Here after unkx80: I thought the aji at b is even worse. =) Charles Ah yes - more common in pro games, I find, though both are seen. Interesting, but would need its own page.
dnerra In this specific situation, it seems to me that b is very severe. I would prefer to defend in gote with black (which would mean playing Charles Having looked at examples, I agree with that. [1] SnotNose: Never saw this before so I'm just checking the safety of the corner in the next few diagrams. I'm not drawing any conclusions yet (needs more thought). Feel free to point out obvious stupid moves or other ideas.
SnotNose: Is ko possible?
SnotNose: This
With --Bill SnotNose: Awesome! Good stuff Bill. The cut at a is big. Is this enough for White? If not, then it would appear that White's wall goes to waste. Perhaps provoking a fight with an attachment (Charles' idea) is better than an approach. (I gotta say, it will still be hard for me to keep my hand from flying to an approach in an actual game. Since it is so unlikely players at my strength would know Kitani's defense here, that's probably okay. We're way up the dan ladder at this point.) Path: BigQuestionMark · Prev: BQM130 · Next: BQM132 This is a copy of the living page "BQM131" at Sensei's Library. ![]() |