Life In 19x19
http://www.lifein19x19.com/

Famous Problem Actually Wrong
http://www.lifein19x19.com/viewtopic.php?f=12&t=7139
Page 1 of 1

Author:  illluck [ Tue Nov 06, 2012 8:10 pm ]
Post subject:  Famous Problem Actually Wrong

So, I was browsing the Baidu Tieba for the first time in a few weeks today, and came across this gem in a post titled "Wrist Strength Challenge: Are you really amateur 1 dan?" at http://tieba.baidu.com/p/1966157755?pn=1

The below problem is #3.

Click Here To Show Diagram Code
[go]$$Bc Black to play and kill
$$ -------------------
$$ | . . O O . . . . . .
$$ | . X O X O . . . . .
$$ | . X O X . . . . O .
$$ | . X O X . . . O . .
$$ | . X O X . . . . . .
$$ | . O X X . . . . . .
$$ | . O O . . . . . . .
$$ | . . . . . . . . . .
$$ | . . . . . . . . . .[/go]


As some of you probably realized, this is a fairly well-known problem which shows up in a lot of books. The book solution is below:

Click Here To Show Diagram Code
[go]$$Bc 5 at 8
$$ -------------------
$$ | . 7 O O 8 6 . . . .
$$ | . X O X O 2 4 9 . .
$$ | . X O X 1 . 3 . O .
$$ | . X O X . . . O . .
$$ | . X O X . . . . . .
$$ | . O X X . . . . . .
$$ | . O O . . . . . . .
$$ | . . . . . . . . . .
$$ | . . . . . . . . . .[/go]


A Chinese amateur 5 dan (coincidentally, the same person who slaughtered me in a 6 stone game at viewtopic.php?f=4&t=5848) passed by and remarked that either himself or the problem creator must have never reached 1 dan.

This is the sequence he pointed out:

Click Here To Show Diagram Code
[go]$$Bc Problem is wrong!
$$ -------------------
$$ | . 4 O O . . . . . .
$$ | 5 X O X O 2 . . . .
$$ | . X O X 1 . 3 . O .
$$ | . X O X . . . O . .
$$ | 6 X O X . . . . . .
$$ | . O X X . . . . . .
$$ | . O O . . . . . . .
$$ | . . . . . . . . . .
$$ | . . . . . . . . . .[/go]


He then admits that he had "done" this problem quite a few times when he was young :p


This was both shocking and strangely motivating for me (makes me feel better about my poor reading :p), so I thought I'd share it.

Given the resistance, the "correct" solution to the problem is as below:

Click Here To Show Diagram Code
[go]$$Bc Ko
$$ -------------------
$$ | . . O O . . . . . .
$$ | . X O X O . 2 . . .
$$ | . X O X . . 1 . O .
$$ | . X O X . . . O . .
$$ | . X O X . . . . . .
$$ | . O X X . . . . . .
$$ | . O O . . . . . . .
$$ | . . . . . . . . . .
$$ | . . . . . . . . . .[/go]

Author:  Alguien [ Wed Nov 07, 2012 1:07 am ]
Post subject:  Re: Famous Problem Actually Wrong

illluck wrote:
[hide]
Click Here To Show Diagram Code
[go]$$Bc Problem is wrong!
$$ -------------------
$$ | . 4 O O . . . . . .
$$ | 5 X O X O 2 . . . .
$$ | . X O X 1 . 3 . O .
$$ | . X O X . . . O . .
$$ | 6 X O X . . . . . .
$$ | . O X X . . . . . .
$$ | . O O . . . . . . .
$$ | . . . . . . . . . .
$$ | . . . . . . . . . .[/go]


Click Here To Show Diagram Code
[go]$$Bc I don't understand your resistance. (I'm barely 3k, though)
$$ -------------------
$$ | . 4 O O 5 6 . . . .
$$ | 9 X O X O 2 7 . . .
$$ | . X O X 1 . 3 . O .
$$ | a X O X . . . O . .
$$ | 8 X O X . . . . . .
$$ | . O X X . . . . . .
$$ | . O O . . . . . . .
$$ | . . . . . . . . . .
$$ | . . . . . . . . . .[/go]


[Edit] Oh, now I see. :w10: at a and b lacks libs to kill. hmm, let me think about that a bit more.

...

Author:  Sverre [ Wed Nov 07, 2012 1:13 am ]
Post subject:  Re: Famous Problem Actually Wrong

Alguien wrote:

Click Here To Show Diagram Code
[go]$$Bc I don't understand your resistance. (I'm barely 3k, though)
$$ -------------------
$$ | . 4 O O 5 6 . . . .
$$ | 9 X O X O 2 7 . . .
$$ | . X O X 1 . 3 . O .
$$ | . X O X . . . O . .
$$ | 8 X O X . . . . . .
$$ | . O X X . . . . . .
$$ | . O O . . . . . . .
$$ | . . . . . . . . . .
$$ | . . . . . . . . . .[/go]


Click Here To Show Diagram Code
[go]$$Wc W resists by winning the semeai.
$$ -------------------
$$ | . O O O . O 2 . . .
$$ | X X O X O O X . . .
$$ | 5 X O X X 4 X . O .
$$ | 1 X O X . . . O . .
$$ | O X O X . . . . . .
$$ | 3 O X X . . . . . .
$$ | . O O . . . . . . .
$$ | . . . . . . . . . .
$$ | . . . . . . . . . .[/go]

Author:  Alguien [ Wed Nov 07, 2012 1:21 am ]
Post subject:  Re: Famous Problem Actually Wrong

I'll keep trying

Click Here To Show Diagram Code
[go]$$Bcm10 This doesn't seem to work for B.
$$ -------------------
$$ | . O O O 1 2 . . . .
$$ | X X O X O O 4 5 . .
$$ | . X O X X . X 6 O .
$$ | 3 X O X . . . O . .
$$ | O X O X . . . . . .
$$ | . O X X . . . . . .
$$ | . O O . . . . . . .
$$ | . . . . . . . . . .
$$ | . . . . . . . . . .[/go]

Author:  Tommie [ Wed Nov 07, 2012 3:04 am ]
Post subject:  Re: Famous Problem Actually Wrong

Could it be that the problem has been wrongly purported?

Has s.o. the original source at hand, i.e. an online link or so?

E.g., if Blacks 1st line string has 1 liberty more it doesn't work (i.e. W's resistance),
or if W has a tigermouth on the 2nd line, Black could atari A14 on B14 (for connection of 2 black groups, thus relevant),
THUS W had to answer the atari @ B13 and
Black would gain a tempo,
for playing A18, being back in the standard line.

Alternatively, if Black had 1 more stone (or liberty) at D13,
then B could play the clamp tesuji F18 (ff) to start with.

Click Here To Show Diagram Code
[go]$$Bc Black to play and kill
$$ -------------------
$$ | . . O O . . . . . .
$$ | . X O X O . . . . .
$$ | . X O X . . . . O .
$$ | . X O X . . . O . .
$$ | . X O X . . . . . .
$$ | 1 O X X . . . . . .
$$ | . . O . . . . . . .
$$ | . W . . . . . . . .
$$ | . . . . . . . . . .[/go]


Click Here To Show Diagram Code
[go]$$Bc Black to play and kill
$$ -------------------
$$ | . . O O . . . . . .
$$ | . X O X O 1 . . . .
$$ | . X O X . . . . O .
$$ | . X O X . . . O . .
$$ | . X O X . . . . . .
$$ | . O X X . . . . . .
$$ | . O O B . . . . . .
$$ | . . . . . . . . . .
$$ | . . . . . . . . . .[/go]


Click Here To Show Diagram Code
[go]$$Bc Black to play and kill
$$ -------------------
$$ | . . O O . . . . . .
$$ | . X O X O 1 . . . .
$$ | . X O X . . . . O .
$$ | . X O X . . . O . .
$$ | . X O X . . . . . .
$$ | . O X X . . . . . .
$$ | . O . . . . . . . .
$$ | . . W . . . . . . .
$$ | . . . . . . . . . .[/go]

(this one NOT working, just for reference)


Click Here To Show Diagram Code
[go]$$Bc Black to play and kill
$$ -------------------
$$ | . . O O . . . . . .
$$ | . X O X O 1 . . . .
$$ | . X O X . . . . O .
$$ | . X O X . . . O . .
$$ | . X O X . . . . . .
$$ | . O X X . . . . . .
$$ | . O . . . . . . . .
$$ | . . . B . . . . . .
$$ | . . W . . . . . . .[/go]



As this (intended tesujis and involved resistances) is fairly easy stuff for high dans,
I rather are convinced that some small yet relevant error in notation has spotted correctly.

[Being @ work - or not ?! :-) :oops: I do not have the resources at hand to consult the books ]

Author:  SoDesuNe [ Wed Nov 07, 2012 6:20 am ]
Post subject:  Re: Famous Problem Actually Wrong

I don't know this particulary problem but I know the theme.

In Rescue and Capture by Yang YiLun there is a similiar problem without liberty shortage for Black.

Click Here To Show Diagram Code
[go]$$Bc Black to play and capture
$$ . . . . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . . . . . |
$$ . . . . . . . . . . . . O . . . |
$$ . . . . . . . . . . . . . . . . |
$$ . . . . . . , . . . X O O . O . |
$$ . . . . . O . . . . X X O X O . |
$$ . . . . . . . . . O X O X X X . |
$$ . . . . . . . . . . O O . . . . |
$$ -------------------[/go]

Author:  jts [ Wed Nov 07, 2012 7:03 am ]
Post subject:  Re: Famous Problem Actually Wrong

Illuck, why can't b just throw in for :b3: , squeeze with :b5: , and then return to the third move in your friend's sequence for :b7: ?

Author:  logan [ Wed Nov 07, 2012 7:25 am ]
Post subject:  Re: Famous Problem Actually Wrong

jts wrote:
Illuck, why can't b just throw in for :b3: , squeeze with :b5: , and then return to the third move in your friend's sequence for :b7: ?

Click Here To Show Diagram Code
[go]$$Bc :w6: @ :b3:
$$ -------------------
$$ | . 5 O O 3 4 . . . .
$$ | . X O X O 2 . 8 . .
$$ | . X O X 1 . 7 . O .
$$ | . X O X . . . O . .
$$ | . X O X . . . . . .
$$ | . O X X . . . . . .
$$ | . O O . . . . . . .
$$ | . . . . . . . . . .
$$ | . . . . . . . . . .[/go]

Purpose of original :b3: is to determine throw-in after White play A or B:
Click Here To Show Diagram Code
[go]$$Bc If A, throw-in. If B, not throw-in.
$$ -------------------
$$ | . . O O . . . . . .
$$ | . X O X O 2 a b . .
$$ | . X O X 1 . 3 . O .
$$ | . X O X . . . O . .
$$ | . X O X . . . . . .
$$ | . O X X . . . . . .
$$ | . O O . . . . . . .
$$ | . . . . . . . . . .
$$ | . . . . . . . . . .[/go]


Click Here To Show Diagram Code
[go]$$Bc B
$$ -------------------
$$ | . 1 O O 2 . 4 . . .
$$ | . X O X O O 3 Q . .
$$ | . X O X X 5 X . O .
$$ | . X O X . . . O . .
$$ | . X O X . . . . . .
$$ | . O X X . . . . . .
$$ | . O O . . . . . . .
$$ | . . . . . . . . . .
$$ | . . . . . . . . . .[/go]

Author:  tchan001 [ Wed Nov 07, 2012 11:09 am ]
Post subject:  Re: Famous Problem Actually Wrong

illluck wrote:
As some of you probably realized, this is a fairly well-known problem which shows up in a lot of books.

Could you please name some of the books where we might be able to find this fairly well-known problem?

Author:  illluck [ Wed Nov 07, 2012 3:45 pm ]
Post subject:  Re: Famous Problem Actually Wrong

@tchan: That's a good question that I've also been wondering about, I've definitely seen a problem that's similar if not the same more than once (my memory isn't good enough to recall the exact position, though the tesuji is definitely the same). I don't know which books have it, but judging from the responses in the tieba post I do trust that the problem did appear (several high dans remarking that they've never noticed this issue despite having done the problem in the past). The post seems to be down at the moment, but I think I remember reading that the poster took the problem from a book and I would think that he must have double checked that he transferred the problem correctly when the resistance was found.

Author:  igrok [ Sun Nov 11, 2012 11:32 pm ]
Post subject:  Re: Famous Problem Actually Wrong

This problem is from "Weiqi Life and Death Drills", Beginner Level, page 5
http://senseis.xmp.net/?WeiqiLifeAndDeathDrills

Author:  illluck [ Wed Aug 21, 2013 5:10 pm ]
Post subject:  Re: Famous Problem Actually Wrong

Another version came up, but still has the same issue:
http://tieba.baidu.com/p/2546098621

Page 1 of 1 All times are UTC - 8 hours [ DST ]
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
http://www.phpbb.com/