Very often apparently simple position are not that easy.
AGA rule : for a theoritical point of view what is the best move for black? a or b ?
What is the best yose move?
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Gérard TAILLE
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pwaldron
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Re: What is the best yose move?
I forget if the AGA rules allow for suicide, but 'a' should be superior to 'b' in any ruleset that does. For black to play 'b' leaves 'a' as a ko threat.
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Gérard TAILLE
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Re: What is the best yose move?
For me AGA rules do not allow suicide. BTW, if you prefer you can also consider you use chinese rules (I mean area counting).pwaldron wrote:I forget if the AGA rules allow for suicide, but 'a' should be superior to 'b' in any ruleset that does. For black to play 'b' leaves 'a' as a ko threat.
I do not understand your point with ko threat : after black "a" white has also a ko threat availbale hasn't she?
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jlt
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Re: What is the best yose move?
If both players play alternatively then a and b are equivalent:
But suppose Black plays a. Later if there is a ko fight, White ataris to make a ko threat, Black doesn't respond and White kills. If another ko appears later then Black still has chances to survive by playing twice in a row. Then Black lives with 2 points and there is one dame left.
On the other hand if Black plays b, after one ignored ko threat by Black and one ignored ko threat by White, Black lives with 3 points. The end result depends on the parity of the number of dame at the end of the game, but with the assumption that the sequence of plays is Black-White-White-Black-Black, then b is superior by 1 point on average.
But suppose Black plays a. Later if there is a ko fight, White ataris to make a ko threat, Black doesn't respond and White kills. If another ko appears later then Black still has chances to survive by playing twice in a row. Then Black lives with 2 points and there is one dame left.
On the other hand if Black plays b, after one ignored ko threat by Black and one ignored ko threat by White, Black lives with 3 points. The end result depends on the parity of the number of dame at the end of the game, but with the assumption that the sequence of plays is Black-White-White-Black-Black, then b is superior by 1 point on average.
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Gérard TAILLE
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Re: What is the best yose move?
Very nice jlt I agree entirely.
Here is an example where it remains only three small areas for the yose.
Black "b" is the best move in order to avoid the following (wrong) sequence :
Here is an example where it remains only three small areas for the yose.
Black "b" is the best move in order to avoid the following (wrong) sequence :
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pwaldron
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Re: What is the best yose move?
You're right. I was just thinking of the suicidal ko threat, but the external atari is there with the other move. My mistake.Gérard TAILLE wrote: For me AGA rules do not allow suicide. BTW, if you prefer you can also consider you use chinese rules (I mean area counting).
I do not understand your point with ko threat : after black "a" white has also a ko threat availbale hasn't she?
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Gérard TAILLE
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xela
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Re: What is the best yose move?
I guess it's the same philosophy as the first example: if white is going to respond to the peep, then the outcome is the same regardless of move order, so the real question is what happens if white ignores the peep?
If white responds: you're going to end up with this position in either case --
and the point is to stop white gaining a tempo with
this way --
If white is going to ignore, then the
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exchange below looks like an example of a reverse in CGT terms: black doesn't gain anything, and possibly loses something (one point from becoming a prisoner)?
So I'd say just play at 
directly, an example of the 123 principle.
What have I missed?
If white responds: you're going to end up with this position in either case --
and the point is to stop white gaining a tempo with
this way --If white is going to ignore, then the
- exchange below looks like an example of a reverse in CGT terms: black doesn't gain anything, and possibly loses something (one point from becoming a prisoner)?So I'd say just play
at directly, an example of the 123 principle.What have I missed?
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Gérard TAILLE
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Re: What is the best yose move?
I understand your point. If white doesn't answer the peep then peeping immediately is better and I agree with you.xela wrote:I guess it's the same philosophy as the first example: if white is going to respond to the peep, then the outcome is the same regardless of move order, so the real question is what happens if white ignores the peep?
If white responds: you're going to end up with this position in either case --
and the point is to stop white gaining a tempo with
If white is going to ignore, then the
So I'd say just play
What have I missed?
However what happens if you suppose all remaining yose points of the board are quite small ? In other word suppose black timing is good and white has to answer the peep in the two considered sequences ? Witch one is the best?
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Gérard TAILLE
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Re: What is the best yose move?
Here is a hint:
AGA rules. By just adding a ko threat and a dame in the upper right corner do you see which of the two moves "a" and "b" is the best?
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Gérard TAILLE
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Re: What is the best yose move?
I agree entirely with you xela, the exchange
followed by the peep at is generally inferior to the immediat peep. I like very much the 123 principle and its application is good sense.A proof of the 123 principle efficiency is that is is quite difficult to change a little the position in order to make the
better.Maybe here is an exemple after a lot of tries: If I am not wrong, due to the white ko threat existing in the top right corner, the exchnage
followed by the standart move is better than the immediat move.Here again it is only an exception. The 123 principle is a very good principle isn't it?