2005 Goodwill Rengo / Discussion

immediate hane  

Velobici: Having played the marked Black stone, I feel compelled to discuss the position ;). I had hoped for . It prevents White from separating Black's stone by playing a, etc.

JoelR: I don't think immediately kills. - save White.

kokiri my feeling was that white shouldn't really live in this situation, but that if white can get the time to play a and force black to capture the stones, then it's probably good enough for white.

If killing isn't possible, then presumably black should take at a rather than play and then seek to force white to live on the side, rather than the corner.

I spent the whole game up until now counting the white stones as dead, oh well...

dnerra: I think the quickest way to live is to play at .

later hane (5 at 3, 9 at )  

JoelR: And, I don't think playing 127 at works either, Black loses the semeai.

Earlier in the corner  

I have other questions about the sequence in the game. I would have played at , but that maybe my kyu-level aggressiveness. Also, I would have pushed at without playing /, on the 123 principle.

dnerra: If you play - before the / exchange, I think W can pull out the cutting stone at a. About at : I would then expect:

Earlier in the corner  

and would help White to reduce the black moyo (but yes, it might still be better than the game).

Looking to the dan-players  

Rich: minue622's comment implied (at least to me) that allowed black to kill; given the difference in skill level, I'm willing to believe that I've missed something, but I can't see it.

One dan answering  

Dieter: Throughout the sequence played in the game, I have never believed killing was possible, because of the throw-in tesuji and the aji of the marked stone (otherwise, making the farmer's hat as in the game, would have killed). Here is anothr variation where White lives.

Moves 101-105  

JoelR: Move 101 () seems small to me. Yes, it does make shape and save the two black stones. But it doesn't put any new threat on White's left side, and the three black stones already have a way out, below. Was this a chance for Black to take sente near or ? How does one choose a move in such areas?

Rich: It seems reasonable to me; Black's play takes a lot of potential from the circled white stone. If black plays, say, , it leaves White with kikashi around the points 3-5 in the alternative diagram. If he plays straight away, at say 'a', and then plays , I don't think black is much better off than in this line of play; more a stylistic choice of thick vs. fast play, IMO. I'm only an SDK, so take that for what it's worth.

DJ: Well, I thought that, slow as it is, is thick, it does poses threats on White's left side (at least as yose goes, I think) and it was casting a menacing glance at : what if Black played at instead?
Still, I am a lowly 2k, so the advice of stronger players would be very welcome!

JoelR: is indeed thick, and honte. I apologize if my comment sounded harsher than I intended. (I am a weaker SDK.) As Rich says, it's probably a matter of style. When I realized the three stones were safe, I started to think tenuki.

Moves 91-100  

. What am I missing here. Black now has eyes and is strong here. The White group on the left has been correspondingly weakened. Circle White moving out at either circle can be dealt with by Black at the square or at the Circle adjacent to the square. Circle Black stones are not big...not cutting stones. Upper left Black group can not be attacked now. Depending upon White's response attack upper left White group or defend bottom moyo on 4th line in closer to the Black stones in the bottom right. What am I missing? Teach me. Please! -- Velobici (prepared for public humiliation ;)

dnerra: I wanted to continue with . I cannot claim I had read this out, but just the shape looks very good for White. Also, I was worried about this sequence:

White continues on top ( connects)  

This scared me.

Dieter: And this was exactly what I had in mind - but that's details. Let me explain why I played

White continues on top ( connects)  

If here, makes and destroys points. Worse, doesn't put any pressure on White and doesn't cooperate well with Bill's circled move: it's a slow combination. However, if Black doesn't move here (attacking elsewhere now that his upper left has few points to make but is strenghtened by Bill's move), White captures the squared stone in sente.

All in all, the challenge here was to efficiently use Bill's move while keeping sente. I do not know whether my was the best way to do that, but certainly its follow-up at made Bill's move less efficient.

Double sente? Um...  

minue622: This was what I worried about.

Bill: This was not to argue with () or (). But dnerra's joking comment about a ko threat might have left the impression that was smaller than it is.

minue622: If you think is smaller than in this diagram, you are underestimating the thickness of white's center.

After , it is nearlly impossible for black to invade into left side, and white's center is going to expand. Tough situatiion for black.

Bill: If I thought that, I would have said that Black should have played instead of . :-) ( in the game) and - both carry large threats, even though the difference between them is small if those threats are answered. That is characteristic of plays that are commonly called double sente. Should I have called them something else?

Double sente?  

Bill: (3 in this diagram), was double sente or close to it, I think. - carries a large threat in . White can save her corner stones with - , but then White has a weakness at a and the stones are heavy.

Can Black show fighting spirits?  

Bill: I decided against because of . Now if B d, W e doesn't look so good for Black. I do not want to run out because of White's ponnuki.

Two questionable moves ?  

Dieter: I think both and are questionable. due to the One-Two-Three principle ...

Connect first  

Black can IMO better connect immediately and wait for White's answer. This is one option. at a and at b another. Compare this diagram with the game, where Black throws away a stone at a instead of getting the extension as here.

White's move?  

White too should play at first : ...

White's move - var 1  

Wrecking the shape

White's move - var 2  

Completely surrounded

White's move - var 3  

Not very pleasant either. at a or b may be even more severe.

Please correct me where I am wrong.

White blocks  

JoelR: I would try , which is a vague threat to run out towards . If White blocks, then the aji in may be enough to settle Black. There's also some aji in the corner, but maybe not it can only be spent once.

dnerra: Sorry for my strong words, but here is out of the question -- it has to be at . Never forget to take profit while attacking!

minue622: I agree with jantiff and dnerra. White should have played , the move to make better result than our real game for white.

White blocks  

Kokiri - This looks pretty good for white, IMO, I think the problem is that black is playing too heavily with . Black is playing in whites sphere of influence, and so ought to be playing lightly.

Shaydwyrm: My idea with was to allow black to play a in sente to settle the group in a pinch. If white chose to respond at b, black would get c as well, gaining something approaching life in the corner. If white played d to capture instead, black would retain good moves to get out ().

Moves 61-70  

jantiff: builds a nice top... but it still pushes from behind; after , Black is settled. So what about at ?

Moves 51-60  

minue622: If white play pincer like , black would play . It is not so hard to stabilize this black group.

Shaydwyrm: strikes me as being too close to thickness, that is, white's one point jump to the right. in the previous diagram seems more than adequate, taking some territory and leaving black with the question of how to handle his two groups on the top and top right, neither of which seems completely stable. a and b look like white's sente.

Velobici: I so much want to play ". Crosscut. Black needs forcing moves to settle in this area." but I feel like I am playing moves too often and not letting others play. <sigh>

Moves 51-60  

minue622: I agree with BILL's , but not with Black's 2 lines extention -b.

White's center influence is scary or has potential for making territories. So, I would play .

Moves 51-60  

jantiff: is dubious to me, how about the classical a ? After White is in a good mood... But maybe the continuation will prove me wrong :)

Bill: I was thinking about the kakari at b. If White responds at a Black can extend to c.

dnerra: I wouldn't have played either; but I think the decision to tenuki and enter White's sphere of influence shows excellent judgement.

Shaydwyrm: Entering white's sphere of influence here looks big, but not necessarily urgent. I would be very concerned about black's group in the top right - if black had played something less pressing, like a or b, as white I would have been inclined to ignore it, allowing the double approach, in favor of attacking black's group in the top right with a move like d.

Moves 41-50  

Velobici: This lower right hand corner appears to be pretty complicated. Any thoughts as to local continuations. White appears to have a lot of aji.

Approach at move 26  

Shaydwyrm: In the game, white approached at "a", but to my kyu sense this move gives me the wrong feeling. The severe one-space pincer at "e" feels almost too good too allow, since black's thickness starts working so well. I was considering two possibilities in this area, the more distant approach at "b" and a wedge somewhere around "c". I am not convinced though that either is the correct move, since, as Jakub implied, the wedge permitting a shimari seems to leave black with an awful lot of territory, and the distant approach is still far enough away from black's wall to allow a close pincer to work well. Right now I am leaning towards the distant approach, since a pincer would at least allow white to much about in the corner with the attachment at "d". Thoughts on the best way to handle the bottom side here?

Approach at move 26  

unkx80: How is ?

Shaydwyrm: This seems ok, but black seems to have gotten his way here - the bottom space was too wide to secure a moyo easily anyway, so as black I would be well satisfied with the corner territory, and he gets to take another big point on the left side too with an approach in the top right. Perhaps, however, this is the best white can expect from letting black get so thick in the bottom right, and will have to try and seek compensation with an attack in the top right. And if that's the case, maybe black should play something like "a" instead of taking a big point on the left, and simply maintain his advantage in territory.

Dieter: I think this is better for White than the game. I do not view the large knight's closure in the bottom left as secure territory. Black's bottom right is not secure either: it can be wrecked by a move at b. This move may well be miai with the extension along the left.

Approach at move 26  

unkx80: If here, then extends and makes a corner approach at the same time. Subsequently, Black a is big but feels somewhat constricted.

Moves 21 to 24  

Jeff: This last move (4) seems off to me (weak player). I'd have expected it on the left edge somewhere to extend and attack that black 4-4 stone. Isn't that the bigger play? Isn't the white base strong enough on the top (for now)? Or should I wait it out and see if white pulls some sort of trick that my eyes don't yet see?

kokiri - isn't making a base for White's stones, it's a pretty strong attack on the two marked black stones, which are weak given the White ponnuki below. It looks like a pretty good move to me. Because of this, I would have been tempted to play at a to take sente, even though it allows W a kikashi at 3. What do people think of the variation below?

Alternative move 24?  

Jeff: Kokiri, now that you show me this alternative where black gets first move in the top-right corner, it looks to me like a fifteen (or more!) point difference. With black getting the first move, I see reasonable territory against the side/corner. With white moving first, I see black in high pressure, making life against the side and hurting white's ability to make territory there, but black not really making significant corner/side territory. Thanks for the explanation by example!

Alternate 19 to 24  

JoelR: Yes, that was my intention with move 19. If White plays under, then he can connect the groups, but Black gets influence and sente. If White plays a ladder breaker, as in the game, then Black at a saves and strengthens the corner, and White should still make the ponnuki and Black has sente.

term100?: How about this proposal: Anyone making a move pledges to make a donation on behalf of the victims of the Indian Ocean tsunamis.

Moves 11 to 20  

Jakub: In the present situation was it wise to strengthen the cutting stone ? My instinct would have been to treat it lightly. I suppose the fascinating thing about Rengo is that another participant can attribute a totally different meaning to one's move than one had in mind.

Velobici: could be a mistake. Black and White both have three groups here that are cutting each other apart. Two of the Black groups are single stones without nearby support. The single White stone has support it to which it can connect. Appears to be hard for Black to capture , due to the weakness of Blacks on stones (, ) and the White stone in the upper left that breaks ladders. Dont think that w6 is light at this time. White has not forced Black into an overconcentrated position or used w6 in order to save significant White stones, so has not yet fulfilled a purpose important enough to compensate for giving it away.

Hane-Sato variation  

Mef: It had been a while since I looked at it, so I just double checked, you're right, in my diagram is played as a double hane, not a nobi.

JoelR: Why isn't this a case of Hane at the Head of One and a Half? I would have cut at the cutting point immediately, but I didn't have the guts to do it in the Rengo.

Rui's Essential Joseki  

Jakub: Rui Naiwei 9 dan gives this continuation as joseki in her Essential Joseki (page 40, Basic Variation 6) but cautions this is a good line only when black does not have good chances for development along his side, which I think is definitely false here. That was the formation I was trying to lead into when I made my move 12 in the rengo

Alternative  

This variation is listed immediately as an alternative which allows a prompt second approach to the corner stone.

Complicated variation  

This complicated variation has occurred in play ("Essential Joseki" p.41, Diagram 29), when white attaches underneath instead of making a second approach.

Black probes  

Black probes for weakness in the white group, but then ...

Black swithches  

Black switches to the other side before resuming the attack, capturing a white stone

Exchange 1  

An exchange is made giving Black thickness on one side for White's survival and a foothold on the other side

Exchange 2  

This is the final position. The question is: can Black make good use of his thickness? I believe in our rengo, it would be advantageous for Black.

Bill:

White strengthens Black's side  

Do the pros really play when Black has something like the stones? says, Thank you, it seems to me.