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#264 Joaz Banbeck vs TegaiS http://www.lifein19x19.com/viewtopic.php?f=37&t=13687 |
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Author: | TegaiS [ Sun Dec 11, 2016 6:48 am ] |
Post subject: | Re: #264 Joaz Banbeck vs TegaiS |
After this White have several options to complicate things.
The first is like this. Numbers to mark stones finished earlier than the variation so it leaves some hope.
The second.
The third has the same idea as the first.
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Author: | Joaz Banbeck [ Sun Dec 11, 2016 8:01 am ] |
Post subject: | Re: #264 Joaz Banbeck vs TegaiS |
Trigger:
Second trigger:
If he accepts the triggers, white creates one eye at B8. ( The circled points are miai ) He might not do them immediately, but he has to sooner or later. If I get A7, that destroys the westward miai pair, then in some variations D8 by me threatens to make one big eye with D7. So I suspect that he will accept the triggers.
Once he has one eye secured, the focus switches to the second one. He has to make it in the middle of the board. If he cuts at 1, I have to respond with 2, otherwise he kills my lower left group.
I think that I can kill. At least, in all variations that I have looked at, I can. ( Although some liberties races that I have read are in my favor by only one move. ) We have managed to get ourselves into a game-deciding fight here. If he dies, I have a 60+ point corner, giving me a winning advantage. If he lives, much of my lower side territory is compromised, giving him a similar advantage. I expect that one of us resigns within 15 moves. There is one compromise possible. He could concede the left side group and play the invasion of 1 below, and if I tried to trap it, it would be just enough to tip the fight in his favor. So I'd have to let him have a successful invasion.
I don't think that we will see this. Based upon my opponent's current play, compromise does not seem to be his style. |
Author: | TegaiS [ Mon Dec 12, 2016 4:06 am ] |
Post subject: | Re: #264 Joaz Banbeck vs TegaiS |
I decided that I like the last variation the most. |
Author: | Joaz Banbeck [ Mon Dec 12, 2016 9:42 am ] |
Post subject: | Re: #264 Joaz Banbeck vs TegaiS |
He chooses the most complicated version. My groups will be hanging on by their fingernails. I hope nobody slips. There is no room for error here. |
Author: | Joaz Banbeck [ Mon Dec 12, 2016 2:00 pm ] |
Post subject: | Re: #264 Joaz Banbeck vs TegaiS |
Again, I almost stumbled into disaster. He has one eye, and if he gets another, his group lives and he wins the game. I can't let him capture D7 and make an eye there. The natural move to play is this. It seems to be the most direct method of connecting D7 out:
But it doesn't work. White plays like this:
I can't play 5 above, or he gets the second eye:
So I must atari with 5 from below. He connects with 6, and I must connect with 7:
All of that is simple and forced. I must play it or he gets an eye at D7. Next, white cuts at 8:
I can't let him play 9 or he will kill my corner. Now with 10 he threatens both my single stone and my group of three. I must rescue the three, or he makes an eye there. [ The really sharp-eyed observer may note that a different play here leads to a ko, but that isn't much of an improvement for me since he has a bunch of internal ko threats. ]
He captures my single stone. It is a false eye, of course, so I'm still in the game. I play 3 which will gain some leverage in the future. ( More on that later ) His reply at 4 is forced. Then I save my three stones with 5. He still only has one eye.
Then he cuts off my corner with 6:
I could play 7 at C1 or D1. It does not get any better. My corner is cut off and still needs another move to have two eyes. Note that if I had not sacrificed at 3, he could now play 8 at B1, killing my corner.
But with 3 in place, he can't:
So white has to pause to capture black 3 with 8, and black gets another move to save his corner:
Having reached the edge of the board, white tries to use it to make an eye:
Normally, black could prevent an eye here:
But 2 threatens to connect underneath, so white gets the second eye - and the game. |
Author: | Joaz Banbeck [ Mon Dec 12, 2016 8:34 pm ] |
Post subject: | Re: #264 Joaz Banbeck vs TegaiS |
In my previous post, I explained why I didn't choose a particular losing move. In this post, I endeavor to explain how that realization led me to the best move - and probably the only move that does not lose. I that previous post, we were looking at this position:
Move 7 is heavy. It does not increase the liberties of anything, and it attempts to save a stone that does not have to be saved - D7 either has to be saved OR rendered useless as an eye. I was looking at this position, dismayed that such a vulgar move was necessary. I started doing sort of tewari analysis, asking myself where other stones should be to make 7 less ugly. Making D7 a false eye without having to save it would be far more elegant. That, of course, means getting two of the four diagonal neighboring points.
In other words, once he plays 4, I don't want a stone at 'a'; I want it at 'b'. If I can hold both 5 and 'b', then D7 becomes a false eye if he captures it.
So I concluded that a stone at 5 would work. It attempts to extricate D7 by connecting outward via either 'c' or 'd'. And it does not link it's fate to D7 by connecting solidly.
If white is really determined to not let D7 escape, then 3 as shown above is in one of the four crucial points to make D7 a false eye. If I haven't wasted a move in the wrong place, I can get a second one of the four. It looks like this:
Black either saves D7 by killing 4, or makes it a false eye by connecting 7 eastward. It was this line of thought - with a lot of useless side branches - that led me to choose E6.
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Author: | TegaiS [ Tue Dec 13, 2016 5:00 am ] |
Post subject: | Re: #264 Joaz Banbeck vs TegaiS |
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Author: | Joaz Banbeck [ Tue Dec 13, 2016 8:15 am ] |
Post subject: | Re: #264 Joaz Banbeck vs TegaiS |
Joaz Banbeck wrote: ... My groups will be hanging on by their fingernails. I hope nobody slips. There is no room for error here. Everything is still hanging together here. His strongest play is to connect at 6 and let me connect at 7:
Now D7 and are both in danger. I can save only one of them. When he captures the other, it is a false eye - I think. If he captures D7, it appears to be fairly simple:
So he will probably go with the other capture at E6:
Here is where white must complicate. If he goes for the immediate capture, black plays the solid move at 4:
And now all white's eyes are at risk if black plays the circled points. Thus white must try some complication like this:
or this:
I don't have time to show all of the lines that I have looked at, but so far I cannot find one that works for white. |
Author: | Joaz Banbeck [ Tue Dec 13, 2016 8:21 am ] |
Post subject: | Re: #264 Joaz Banbeck vs TegaiS |
Triggers:
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Author: | TegaiS [ Tue Dec 13, 2016 9:17 am ] |
Post subject: | Re: #264 Joaz Banbeck vs TegaiS |
I hoped for something like this. After Black don't have time to make two eyes with B1.
But I'm afraid Black can give up the D4 stone now
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Author: | Joaz Banbeck [ Tue Dec 13, 2016 12:53 pm ] |
Post subject: | Re: #264 Joaz Banbeck vs TegaiS |
A third time in this corner he chooses the most complicated line, thus giving me the greatest opportunity to make a mistake. Generally, a player who believes that he has the upper hand wants to simplify matters so as to not lose his advantage in an oversight. Conversely, a player who believes that he is at a disadvantage wants to give his opponent maximum chance to fail - even if he knows that he himself may fall into a pit, for he is no worse off if he does. I infer from this repeated choice of complicated lines that my opponent thinks that he is in a losing position. ( Although logic compels me to admit that he may have found a winning line that just happens to be at the end of a series of junctures, and the most complicated choice at each of those junctures just happens to lead to the one winning result. ) |
Author: | TegaiS [ Tue Dec 13, 2016 6:09 pm ] |
Post subject: | Re: #264 Joaz Banbeck vs TegaiS |
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Author: | Joaz Banbeck [ Tue Dec 13, 2016 7:23 pm ] |
Post subject: | Re: #264 Joaz Banbeck vs TegaiS |
Triggers:
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Author: | TegaiS [ Tue Dec 13, 2016 7:56 pm ] |
Post subject: | Re: #264 Joaz Banbeck vs TegaiS |
Like this I'm about 15 points behind in my count. The embarrassing thing is that I die in gote.
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Author: | Joaz Banbeck [ Tue Dec 13, 2016 11:25 pm ] |
Post subject: | Re: #264 Joaz Banbeck vs TegaiS |
I'm playing the most resilient corner shape that I can. He can't go for the vital point because he dies first:
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Author: | TegaiS [ Wed Dec 14, 2016 8:14 am ] |
Post subject: | Re: #264 Joaz Banbeck vs TegaiS |
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Author: | Joaz Banbeck [ Wed Dec 14, 2016 8:43 am ] |
Post subject: | Re: #264 Joaz Banbeck vs TegaiS |
*Screeeech* ...Wait...what?? I expected this:
White 16 forces black 17, otherwise black's three stones get into trouble. Then white plays 18 somewhere in the shaded area.
I don't mind an opportunity to extricate my three stones. And he still can't win a liberties race against my corner:
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Author: | TegaiS [ Thu Dec 15, 2016 11:56 pm ] |
Post subject: | Re: #264 Joaz Banbeck vs TegaiS |
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Author: | tj86430 [ Fri Dec 16, 2016 2:08 am ] |
Post subject: | Re: #264 Joaz Banbeck vs TegaiS |
TegaiS wrote: Like this I'm about 15 points behind in my count. The embarrassing thing is that I die in gote.
Is needed? Can't black play this:
And still capture E2 group before white can kill black corner? |
Author: | Joaz Banbeck [ Fri Dec 16, 2016 2:22 pm ] |
Post subject: | Re: #264 Joaz Banbeck vs TegaiS |
I don't see where he is going with this. As long as I can kill this group faster than white can kill my corner, I'm OK. My move preserves my lead in the liberties race. And it prevents the connection underneath. So it can't be bad, right? White must see that he can't get eyes in a space that small. And he also must have read the same liberties race that I have and come to the same conclusion. So where is he going with this sacrifice? The only thing this does for white is that it lets him pressure the line of four black stones at D4/G4. He removes liberties on the underside by creating this group. It looks like it might last long enough to let the white stones on the upper side attack the four black stones from the top - and thereby get enough sente moves to make an extra eye. I've looked at that possibility a lot. And it doesn't work. The four black stones are always one move ahead in a liberties race, or able to connect eastward. |
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