? (Yes, mistakes have been made by both sides up to this point. And I didn't get the right move in the game: many more mistakes were made by both sides.)Edited to add: all ladders are in white's favour.
Tsumego problem from one of my recent games
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xela
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Tsumego problem from one of my recent games
White's best reply to ? (Yes, mistakes have been made by both sides up to this point. And I didn't get the right move in the game: many more mistakes were made by both sides.)
Edited to add: all ladders are in white's favour.
? (Yes, mistakes have been made by both sides up to this point. And I didn't get the right move in the game: many more mistakes were made by both sides.)Edited to add: all ladders are in white's favour.
Last edited by xela on Wed Nov 06, 2019 5:53 am, edited 1 time in total.
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Bill Spight
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Re: Tsumego problem from one of my recent games
I would call this a "joseki" problem, not a tsumego problem, I suppose it arose like this.
elsewhere
This is a double approach joseki.
is old fashioned. The modern (but pre-AI) play is the keima at a.
I suppose the ladder works.
But I doubt if White can afford to abandon the
stone.
is a well known tesuji. Actually, there are two ladders, aren't there?
elsewhereThis is a double approach joseki.
is old fashioned. The modern (but pre-AI) play is the keima at a.I suppose the ladder works.
But I doubt if White can afford to abandon the
stone. is a well known tesuji. Actually, there are two ladders, aren't there? 
looks good. It is a ladder breaker for the ladder starting with a, and if 
plays the other ladder 
takes advantage of the Black damezumari, thanks to the 
- 
is at b, 
at 25 makes life difficult for Black. 
might also be at a.
Last edited by Bill Spight on Wed Nov 06, 2019 4:40 am, edited 1 time in total.
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EdLee
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Uberdude
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Re: Tsumego problem from one of my recent games
xela, I could imagine you made the wrong reply to black 3, but to black 1?!
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xela
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Re: Tsumego problem from one of my recent games
The curse of looking ahead: I could visualise the position after black 3, saw that the ladders were against me, but couldn't see the next move for white. So I didn't go down that path. Instead I went for a trade (there was interesting stuff happening in the top left corner too, but I can't remember enough of the game to be worth posting).Uberdude wrote:xela, I could imagine you made the wrong reply to black 3, but to black 1?!
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Bill Spight
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Re: Tsumego problem from one of my recent games
A couple of things. First, just because Black has the option of capturing some White stones is not a reason not to sacrifice them.xela wrote:The curse of looking ahead: I could visualise the position after black 3, saw that the ladders were against me, but couldn't see the next move for white. So I didn't go down that path. Instead I went for a trade (there was interesting stuff happening in the top left corner too, but I can't remember enough of the game to be worth posting).Uberdude wrote:xela, I could imagine you made the wrong reply to black 3, but to black 1?!
As you said, you made a trade. If you give up the stones on the left side, the five Black stones to the right are still cut off and attackable. As it happens, the damezumari is very bad for those stones. But if not, White could still attack them. Giving up the single stone, however, unites all the Black stones. That stone is hard to sacrifice.Second, something that I noted without reading is the vulnerability of the bamboo joint. If it is threatened, the threat and connection take away two dame. So in the position you show, the stones connected by a bamboo joint appear to have 6 liberties. But you have to subtract two for the connection, leaving 4 liberties (or allowing the cut). Wilcox says that stones with five dame are alive in a fight. That's not always so, but stones with only 4 dame are vulnerable. Extending from the
stone leaves them with 3 dame (or allows cut). Then the hane leaves them with 2 dame. Bingo! 
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins
Visualize whirled peas.
Everything with love. Stay safe.
At some point, doesn't thinking have to go on?
— Winona Adkins
Visualize whirled peas.
Everything with love. Stay safe.
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Uberdude
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Re: Tsumego problem from one of my recent games
The shortage of liberties in this bamboo is very similar to this non-joseki variation punishment http://josekipedia.com/#path:pdqfqindpf ... ohphoioepe (though weirdly josekipedia doesn't continue with the ladder at q18 going for an unncessary compromise!), which explains why joseki is q15 pole connection even though it makes an empty triangle, and bamboo at p16 is worse.
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xela
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Re: Tsumego problem from one of my recent games
This has been a blind spot for me (using the past tense because, now we've had this conversation, I'll never get it wrong again). I simply didn't see the black stones as attackable. I saw them as having plenty of liberties, with white F4 being blighted.Bill Spight wrote:...something that I noted without reading is the vulnerability of the bamboo joint. If it is threatened, the threat and connection take away two dame. So in the position you show, the stones connected by a bamboo joint appear to have 6 liberties. But you have to subtract two for the connection, leaving 4 liberties...
And here we have a nice case study: the AI told me I'd missed something interesting in the position, but the conversation with humans showed up the underlying gap in my thought process :-)
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Uberdude
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Re: Tsumego problem from one of my recent games
Even if black didn't push to reduce his liberties and missed the hane for white 4, I'd still imagine trades like this:
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xela
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Re: Tsumego problem from one of my recent games
Here's another one. Again I didn't find the move in the game, but KataGo showed me an interesting way to connect.
I wimped out and played at a not realising I could jump a bit further. After 
, how does black connect to safety?
I wimped out and played
at a not realising I could jump a bit further. After , how does black connect to safety?
Last edited by xela on Thu Dec 26, 2019 12:27 am, edited 1 time in total.
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xela
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Re: Tsumego problem from one of my recent games
Yes, that seems to work too, but KataGo showed me something much more stylish!
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Uberdude
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Re: Tsumego problem from one of my recent games
It's easy to connect with the standard shape of kosumi or attach against the White knight move, though there may be better moves given White's thinness and Black's support above. But I would be more concerned with reading counters (or evaluating the natural trade) to this White resistance.
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Uberdude
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Bill Spight
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Re: Tsumego problem from one of my recent games
Here is where Sonoda's theory of diagonal lines might have helped.xela wrote:Here's another one. Again I didn't find the move in the game, but KataGo showed me an interesting way to connect.
I wimped out and played
It is obvious that
is OK, so why not a? Worth checking out. After
exchange does not look good for Black.The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins
Visualize whirled peas.
Everything with love. Stay safe.
At some point, doesn't thinking have to go on?
— Winona Adkins
Visualize whirled peas.
Everything with love. Stay safe.