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This 'n' that http://lifein19x19.com/viewtopic.php?f=12&t=12327 |
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Author: | Bill Spight [ Fri Feb 26, 2016 11:25 am ] |
Post subject: | Re: This 'n' that |
Let's tackle the harder problem first. It is not obvious, but Black has 1.25 eyes, 0.5 of an eye on the side and 0.75 of an eye in the corner, and has to make another 0.75 of an eye to live. She does this by making 1.5 eyes in the corner. Stage 1 is to get ![]() ![]() ![]() White cannot afford to play atari at 4. Black now has and a half eyes in the corner. Added to the half eye on the side gives two eyes for life. ( ![]() ![]() White can hold Black to one eye in the corner in gote. Black to play can make two eyes in the corner by oshitsubushi, also in gote. ![]() In the book White played ![]() ![]() ![]() After White holds Black to one eye in the corner Black has to pick up half an eye on the side. She does this by an under the stones sacrifice, which is familiar to experienced tsumego solvers. ![]() ![]() I don't know whether Kobayashi père composed this problem or whether it is a famous ancient problem, but it is pretty cool, isn't it? ![]() ![]() ![]() |
Author: | Bill Spight [ Thu Apr 14, 2016 9:53 am ] |
Post subject: | Re: This 'n' that |
I'm back! ![]() I just ran across a nice opening problem in an ancient game. It's easy. ![]() At least if you have seen this kind of play before. ![]() Enjoy! ![]() |
Author: | EdLee [ Thu Apr 14, 2016 9:25 pm ] |
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Author: | Uberdude [ Sat Apr 16, 2016 8:25 am ] |
Post subject: | Re: This 'n' that |
A while ago.. Kirby wrote: If it were my game, I'd first try to make white heavy with a peep, and then I'd take territory on the bottom. There are other moves that might give more pressure to black, but I don't seem to have a clear plan as to how to follow up: Kirby, I thought of you when Ali Jabarin 1p played move 68 in this KGS game today ![]() |
Author: | Bill Spight [ Sun Apr 17, 2016 8:50 am ] |
Post subject: | Re: This 'n' that |
Ed got it right. ![]() When I was 4 kyu, I think that I probably would have played ![]() The game was played in 1802 between Yasui Chitoku (W) and Sato Shunsaku. Sato played ![]() Although ![]() ![]() ![]() ![]() ![]() ![]() The game record: |
Author: | Bill Spight [ Sun Apr 17, 2016 9:33 am ] |
Post subject: | Re: This 'n' that |
Here is another Chitoku game, a castle game vs. Honinbo Retsugen (W) ![]() I confess that I would have missed ![]() Retsugen plays ![]() ![]() ![]() ![]() Chitoku contents himself with the extension to ![]() ![]() Chitoku makes the standard reducing play at ![]() Where did Chitoku play next? (FWIW, I think that it is the only play. ![]() Enjoy! ![]() |
Author: | EdLee [ Sun Apr 17, 2016 10:15 am ] |
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Hi Bill, |
Author: | bayu [ Sun Apr 17, 2016 10:59 am ] |
Post subject: | Re: This 'n' that |
first a question: why is blocking instead of 32 not good/inferior? It would defend the cutting point. Is it because the thickness is not that good with the open skirt and that white would expose the cut at N16? Or is it that black gets a great point elsewhere? As for your question: |
Author: | Bill Spight [ Sun Apr 17, 2016 4:04 pm ] |
Post subject: | Re: This 'n' that |
bayu wrote: first a question: why is blocking instead of 32 not good/inferior? It would defend the cutting point. Is it because the thickness is not that good with the open skirt and that white would expose the cut at N16? Or is it that black gets a great point elsewhere? Well, I missed ![]() ![]() |
Author: | Bill Spight [ Tue Apr 19, 2016 6:46 pm ] |
Post subject: | Re: This 'n' that |
bayu got it right. ![]() The central turn, ![]() ![]() ![]() ![]() Here is the game record. |
Author: | Bill Spight [ Wed Apr 20, 2016 12:53 pm ] |
Post subject: | Re: This 'n' that |
Now, at long last, the easy problem from Igo Tsumekata. The first play is kind of obvious. ![]() If ![]() ![]() If ![]() ![]() ---- Practical problems? I like this problem because I think that it is practical. Not that it will occur as is in any game, but the idea is important and easy to grasp. ![]() There is a school of thought that the best problems are the practical ones, those that come up in real games or are similar to positions that do. That is one reason that it is good to study your own games. The problems that they present are definitely practical. ![]() But I also like the idea of thoroughly understanding positions in limited regions of play; like the 7 point corner in the first variation. Now, that position is a practical one to know. But what about this position? There is a certain charm to the play on these four points. And yes, it is related to the game of Nim. ![]() But that is the thing. I discovered it. I have never seen the like in a game, nor do I expect to. And even if it were to occur in a game, the chance that knowing how to play it would be crucial is miniscule. I do think that there is some practical value in seeing the under the stones possibilities, though. ![]() |
Author: | EdLee [ Wed Apr 20, 2016 11:50 pm ] |
Post subject: | |
Hi Bill, Thanks for posting these. |
Author: | Bill Spight [ Fri Apr 22, 2016 9:37 am ] |
Post subject: | Re: This 'n' that |
I think that Igo Tsumekata ( http://dl.ndl.go.jp/info:ndljp/pid/861034/36 ) has a lot of practical problems, most of them at the kyu level. However, to read the answers in the text it helps to know the Chinese numerals. ![]() ![]() Here is an easy one. And practical, I think. ![]() Enjoy! ![]() |
Author: | EdLee [ Fri Apr 22, 2016 9:49 am ] |
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Author: | EdLee [ Fri Apr 22, 2016 11:15 am ] |
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Bill Spight wrote: to read the answers in the text it helps to know the Chinese numerals. Hi Bill,![]() The Arabic numerals were an excellent invention. ![]() Do you happen to know when this book was originally published ? Very practical -- Thanks. |
Author: | Bill Spight [ Fri Apr 22, 2016 12:42 pm ] |
Post subject: | Re: |
EdLee wrote: Do you happen to know when this book was originally published ? It was part of a set published in 1901. The father died in 1893. I don't know if there was an earlier edition. |
Author: | jeromie [ Fri Apr 22, 2016 1:47 pm ] |
Post subject: | Re: This 'n' that |
Without peeking at Ed's answer, here's my solution. That's a nice problem! |
Author: | Bill Spight [ Fri Apr 22, 2016 10:19 pm ] |
Post subject: | Re: This 'n' that |
Here is a problem that appears in several sources. For background, say that Black invades the top left White corner. ![]() ![]() ![]() Suppose that Black now tenukis. That yields the problem position. Modern versions strengthen White on the left side, to keep Black contained. Let's do that for the problem diagram. White to play in the top left corner, with what result? Enjoy! ![]() |
Author: | EdLee [ Fri Apr 22, 2016 11:45 pm ] |
Post subject: | |
Bill Spight wrote: It was part of a set published in 1901. The father died in 1893. Hi Bill,Just curious: how did you come across this set (and the website) ? I see a Mr. Kobayashi (?) and his son(?); was he/were they pro ? Or Honinbo or other title holders ? ![]() |
Author: | EdLee [ Sat Apr 23, 2016 12:18 am ] |
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