I started going through this book just for leisure, and have followed most of Yuan's explanations so far, until this position:
He says that black would like to play "A", but this is problematic:
He says that cutting off the two marked black stones poses a problem since the bottom left star point is white.
I don't get it, though. What's the big deal?
White gets pressed down on the second line. Why does it matter that the bottom left is a white star point?
Question from Yuan Zhuo's "understanding pro games"
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Kirby
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John Fairbairn
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Re: Question from Yuan Zhuo's "understanding pro games"
White doesn't get pushed down on the second line. He can push up and cut. Black could presumably accept that as a sacrifice if he had a stone to the left. Alternatives for pressing down (e.g. to the left of 7) seem to be affected by the colour of the stone, especially as at some point, once White is stable, Black has to worry about the ko in the corner. It seems unlikely that Black can complete any pressing manoeuvres without leaving horrendous weaknesses, and the ko is almost a picnic ko for White.
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alphaville
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Re: Question from Yuan Zhuo's "understanding pro games"
That is not correct: if white pushes up and cuts after black 7, black plays atari once on the 5th line, then descends and captures white.John Fairbairn wrote:White doesn't get pushed down on the second line. He can push up and cut.
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gamesorry
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Re: Question from Yuan Zhuo's "understanding pro games"
White might sacrifice the three stones given that the bottom left star point is white:That is not correct: if white pushes up and cuts after black 7, black plays atari once on the 5th line, then descends and captures white.
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Kirby
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Re: Question from Yuan Zhuo's "understanding pro games"
Given the capture of the three stones, this doesn't seem bad to me for black. Would white really play this way?
I guess white has sente.
I guess white has sente.
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alphaville
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Re: Question from Yuan Zhuo's "understanding pro games"
I agree with you, I would hate to be white in this position...Kirby wrote:Given the capture of the three stones, this doesn't seem bad to me for black. Would white really play this way?
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Kirby
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Re: Question from Yuan Zhuo's "understanding pro games"
For what it's worth, the game continued like this:
The fact that black played 7 seems to suggest that he thought the bottom was bigger than the corner.
Still not sure about the comment from the OP, though.
The fact that black played 7 seems to suggest that he thought the bottom was bigger than the corner.
Still not sure about the comment from the OP, though.
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hyperpape
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Re: Question from Yuan Zhuo's "understanding pro games"
Can White push up and cut without extending first? It looks like a one way street to me, but I can't post right now as I'm on my phone.
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Vesa
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Re: Question from Yuan Zhuo's "understanding pro games"
I think the original book explanation doesn't really help. The normal continuation should be like this:
And only after this the cut is troublesome.
Cheers,
Vesa
And only after this the cut is troublesome.
Cheers,
Vesa
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John Fairbairn
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Re: Question from Yuan Zhuo's "understanding pro games"
I have no idea whether the push up and cut is what Zhou had in mind, and I'd be reluctant to play it myself without preparation, but I don't think it's too grim for White if he does play it at once. Let's make some simplifying assumptions and re-consider.
Assume White uses his sente to play 1 (I don't think he should as this group has elasticity and an easy rout to the centre, but it seems the simplest assumption). Note also that White hasn't really lost three stones by tewari as Black has had to make two silly fill-in moves on the edge. Black has thus achieved a group worth about 10-11 points with little scope for expansion. That is no more than par, based on the further simplifying assumptions that a player can achieve a maximum five groups and par for final territory (361 points - average ~250 moves) is 110 / 2.
In that position I could easily be persuaded that White's right-side group can be counted as at least 10 given that it does have scope for expansion.
Continuing the simplification, we can assume that the four stones each in the upper left cancel out, so we are then left with two Black's stones on the right (one of which is far too close to thickness) being equated with White's budding moyo in the lower left. Plus he has komi.
I'd reckon that White would not really play 1, but something like A (in which case the moyo already becomes a jimoyo) and rely on the elasticity of his group on the right, especially as any accretions to this group if Black attacks from the corner side will impact badly on Black's side stone.
I don't know enough to say this means White is ahead but I certainly don't think his position can be glibly written off just because three stones went to Valhalla.
Also, I am suspicious of the comment by Zhou. If he did indeed use the phrase "poses problems" in the book I'd still assume he thought in Chinese and so his thought process could include the meaning "will pose problems", i.e. it leaves bad aji.
Assume White uses his sente to play 1 (I don't think he should as this group has elasticity and an easy rout to the centre, but it seems the simplest assumption). Note also that White hasn't really lost three stones by tewari as Black has had to make two silly fill-in moves on the edge. Black has thus achieved a group worth about 10-11 points with little scope for expansion. That is no more than par, based on the further simplifying assumptions that a player can achieve a maximum five groups and par for final territory (361 points - average ~250 moves) is 110 / 2.
In that position I could easily be persuaded that White's right-side group can be counted as at least 10 given that it does have scope for expansion.
Continuing the simplification, we can assume that the four stones each in the upper left cancel out, so we are then left with two Black's stones on the right (one of which is far too close to thickness) being equated with White's budding moyo in the lower left. Plus he has komi.
I'd reckon that White would not really play 1, but something like A (in which case the moyo already becomes a jimoyo) and rely on the elasticity of his group on the right, especially as any accretions to this group if Black attacks from the corner side will impact badly on Black's side stone.
I don't know enough to say this means White is ahead but I certainly don't think his position can be glibly written off just because three stones went to Valhalla.
Also, I am suspicious of the comment by Zhou. If he did indeed use the phrase "poses problems" in the book I'd still assume he thought in Chinese and so his thought process could include the meaning "will pose problems", i.e. it leaves bad aji.
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alphaville
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Re: Question from Yuan Zhuo's "understanding pro games"
Black can just protect against the cut next, why is this troublesome?Vesa wrote:I think the original book explanation doesn't really help. The normal continuation should be like this:
And only after this the cut is troublesome.
Cheers,
Vesa
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Vesa
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Re: Question from Yuan Zhuo's "understanding pro games"
As I said above, the book doesn't answer the question. Maybe black wants to play elsewhere (A)?alphaville wrote:Black can just protect against the cut next, why is this troublesome?Vesa wrote:I think the original book explanation doesn't really help. The normal continuation should be like this:
And only after this the cut is troublesome.
Cheers,
Vesa
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hyperpape
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Re: Question from Yuan Zhuo's "understanding pro games"
What am I missing? I can't find a decent move for black. 
, 
and 
appear forced if black wants to attempt to save the third line stone.
, and appear forced if black wants to attempt to save the third line stone.-
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Re: Question from Yuan Zhuo's "understanding pro games"
His wording, as it appears in the SmartGo version of the book, is:John Fairbairn wrote: Also, I am suspicious of the comment by Zhou. If he did indeed use the phrase "poses problems" in the book I'd still assume he thought in Chinese and so his thought process could include the meaning "will pose problems", i.e. it leaves bad aji.
"The result is that the (two triangled) stones are cut off. Black is not ready for this. The (two triangled) stones are too vulnerable with the white stone in the lower left corner."
Since he said the two stones are vulnerable, I'd be surprised if white's push, cut, and sacrifice strategy is the one he had in mind.
Maybe he did, though. Or maybe it's just an attempt to explain the game move.
Still not sure I understand enough to avoid playing the 3-3 as black in my own game, but the discussion is interesting.
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Kirby
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Re: Question from Yuan Zhuo's "understanding pro games"
Play 7 below 1.hyperpape wrote: What am I missing? I can't find a decent move for black.
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