Life In 19x19 http://www.lifein19x19.com/ |
|
Opening problem http://www.lifein19x19.com/viewtopic.php?f=11&t=8072 |
Page 1 of 1 |
Author: | PeterPeter [ Tue Mar 12, 2013 12:46 pm ] |
Post subject: | Opening problem |
In this question about the best move to play next, I did get the correct answer (not shown), but I also had a couple of candidate moves than I am less sure about. 'a' was only rated 6/10, with the commentary being that it "is not appropriate here, because Black's position on the lower left is open at the edge of the board." Can anyone explain this further? 'b' was not rated at all. What is wrong with this cap? I did not like the look of 'c', which was rated 8/10, after white replies at 'd'. I thought this invasion looked unwise and unnecessary. What if white replied at 'e' instead? |
Author: | amnal [ Tue Mar 12, 2013 12:56 pm ] |
Post subject: | Re: Opening problem |
Quote: 'a' was only rated 6/10, with the commentary being that it "is not appropriate here, because Black's position on the lower left is open at the edge of the board." Can anyone explain this further? a is not an interesting place to make territory or a moyo because white can undercut it or black has to spend a move there in gote. Meanwhile, white can't make much territory there himself because any large extension can probably be invaded thanks to black's thickness, so the area isn't that interesting to play in For instance, if black plays some simple joseki that he vaguely remembers reading in a book somewhere, white's move 6 is massive and leaves black with very little territory, not much more influence than he already had, and a stronger white corner than before. Quote: 'b' was not rated at all. What is wrong with this cap? I think it's probably just a bit lukewarm. It may well be fine, particularly for non-high-dans, but it isn't sufficiently active. It doesn't really threaten anything as white's two stones both have loads of space around them, and white can even just be induced to become strong near the shimari. In return, black needs to claim that the cap helps his centre enough, but it's wide open right now and it may be fairly easy for white to make the cap a bad move by making the moyo too small for it to matter before it even becomes important. |
Author: | EdLee [ Tue Mar 12, 2013 1:19 pm ] |
Post subject: | |
Author: | PeterPeter [ Tue Mar 12, 2013 1:24 pm ] |
Post subject: | Re: Opening problem |
That was only rated 5/10. Nothing more was said about it. My feeling was that it was useful, but not that urgent. If black wanted to block off that corner, he could do so later? |
Author: | EdLee [ Tue Mar 12, 2013 1:34 pm ] |
Post subject: | |
Peter, may I ask which book the problem came from, who's the target audience, and who's the author (his/her level) ? ( Ishigure Ikuro 石榑 郁郎. In 1973 -- when the book was written? -- 7p. Now: 9p. ) Here's the pro game (first 60 moves) -- the problem changed the order of a few moves, which makes a huge difference: ( ![]() ![]() ![]() or, the problem came from another actual pro game with just ever so slightly different moves! ![]() |
Author: | PeterPeter [ Tue Mar 12, 2013 1:49 pm ] |
Post subject: | Re: Opening problem |
It is "In the Beginning" by Ikuro Ishigure - I think he is 9 dan? I am looking at the excellent sequence which you later added, and cannot find a way for that to end well for black. The opening sequence is not given; just the position. He does allow for lots of different answers, hence the scale of 1 to 10, rather than right/wrong (though he is confident there is always one answer a bit better than the others). |
Author: | Magicwand [ Tue Mar 12, 2013 2:05 pm ] |
Post subject: | Re: Opening problem |
Surprisingly every pros will agree on such problem. Which means they see what we don't. |
Author: | Unusedname [ Tue Mar 12, 2013 2:23 pm ] |
Post subject: | Re: Opening problem |
What I think of "c" i suppose something like this. The white stone is separated The corner can still be invaded Black's enclosure is strong so making a base might be considered slow Something like c might become sente against the coner which would allow black to turn the side into territory as far as white playing the cap? the corner is still open the stone is still separated and white is building a useless wall that is facing thickness. |
Author: | amnal [ Tue Mar 12, 2013 2:53 pm ] |
Post subject: | Re: Opening problem |
Unusedname wrote: I had thought black might have this 5 in mind, aiming to make the white stone on the side weaker and claiming that 1 and 3 are in an okay position because of black's thickness. Plus black a is very annoying for white so white might prefer to play 4 one line lower, but then he can't attack black's stones as powerfully. |
Author: | Uberdude [ Tue Mar 12, 2013 3:24 pm ] |
Post subject: | Re: Opening problem |
EdLee wrote: Here's the pro game (first 60 moves) -- the problem changed the order of a few moves, which makes a huge difference: ( and already played; is a different atari than B4, etc. -- unless the database is wrong, or, the problem came from another actual pro game with just ever so slightly different moves! ) This is strange. In the book Ishigure says that his white opponent played b17, which was a mistake, rather than f14 which is the key point and would punish black, as in the game Ed posted. And that he himself made a mistake in playing c16 and hoping that his opponent descended to b17 (which he obliging did) rather than jumping immediately to the key point. So either he is misremembering, or there was another very similar pro game that's not in GoGoD. Magicwand wrote: Surprisingly every pros will agree on such problem. Which means they see what we don't. Ishigure himself says he got it wrong ![]() P.S. c3 vs b4 actually makes quite a difference to the push through at g4. |
Author: | Bill Spight [ Tue Mar 12, 2013 4:28 pm ] |
Post subject: | Re: Opening problem |
Congratulations on finding the cap. You are thinking about the whole board. (Sorry, lovelove. ![]() There is a proverb that says to play a knight's move to the cap. But in this case, if ![]() ![]() ![]() But White will respond at ![]() ![]() To justify the existence of ![]() ![]() ![]() ![]() ![]() ![]() |
Page 1 of 1 | All times are UTC - 8 hours [ DST ] |
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group http://www.phpbb.com/ |