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Life & Death Encyclopedia Problems

Posted: Thu Aug 05, 2010 9:36 am
by prokofiev
I've recently started working through the problems from the Elementary section of Cho's Encyclopedia of Life & Death found on tsumego.tasuki.org and thought I'd post some of the ones I found interesting here. I'm not so far yet: I'm just past 100 and there are 900 problems in the elementary section alone!

Despite the Study Journal section, this isn't really to hold myself accountable and I don't promise to keep doing them, but it seemed nice to post some of the more interesting ones as I go along (if I keep going along). Feel free to join in and offer solutions. I do "have the answers" for the ones I post (unless I get stuck on one and then I'll mention that), but only in that I've worked them out myself, seeing as there are no solutions given.

As for why I chose these problems: they're very easily portable (being electronic) and the idea of a progressive encyclopedia that introduces all necessary ideas for later tsumego in earlier ones appeals. I don't know to what extent that goes on really, but from the problems I've solved (and glancing further) it seems it does, for example:

Problem 67 comes first, but problem 68 is in some sense a prerequisite or hint. It's a bit funny they come in that order, but perhaps the idea is that if you get stuck on 67, you decide to skip it for a little while and keep going and then see 68. (It seems also that the encyclopedia itself was not just a list of problems, so perhaps the translation into a list of problems has created these peculiarities.)

Problem 67:

Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|...X.XO.
$$|X.OXXXO.
$$|..XOOOO.
$$|.OO.....
$$|........[/go]


Problem 68:
Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|...X.XO.
$$|XXOXXXO.
$$|OO.OOOO.
$$|.OO.....
$$|........[/go]


This next one took me much longer than the surrounding ones for some reason (as always, it looks very simple in retrospect):

Problem 45:
Click Here To Show Diagram Code
[go]$$Bcm1
$$|-------
$$|.....O.
$$|XXOXXO.
$$|..XOOO.
$$|O.XO...
$$|.OO....
$$|.......[/go]


And this next one I put down and came back later to, only to find that in the interim I'd seen and solved a very similar problem on kgs!

Problem 97
Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|...XO...
$$|.XO.OXX.
$$|.OXO.OX.
$$|..XOOOX.
$$|..XXXX..
$$|........[/go]


A mild comment/hint:
The key is Black's second move.


A few others I marked down as more interesting/challenging than their surroundings: 17, 38, 78, 102.

Re: Life & Death Encyclopedia Problems

Posted: Thu Aug 05, 2010 10:29 am
by Stable
Yes I love those collections for exactly that reason. I'm currently working through the 2nd.

Re: Life & Death Encyclopedia Problems

Posted: Thu Aug 05, 2010 10:33 am
by prokofiev
Stable wrote:Yes I love those collections for exactly that reason. I'm currently working through the 2nd.


Glad to hear it from someone who's further along!

Re: Life & Death Encyclopedia Problems

Posted: Thu Aug 05, 2010 10:47 am
by SoDesuNe
Problem 67:

Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|...X.XO.
$$|X.OXXXO.
$$|..XOOOO.
$$|.OO.....
$$|........[/go]


Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|.3.X.XO.
$$|X1OXXXO.
$$|.2XOOOO.
$$|.OO.....
$$|........[/go]


Problem 68:
Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|...X.XO.
$$|XXOXXXO.
$$|OO.OOOO.
$$|.OO.....
$$|........[/go]



Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|.1.X.XO.
$$|XXOXXXO.
$$|OO.OOOO.
$$|.OO.....
$$|........[/go]



Problem 45:
Click Here To Show Diagram Code
[go]$$Bcm1
$$|-------
$$|.....O.
$$|XXOXXO.
$$|..XOOO.
$$|O.XO...
$$|.OO....
$$|.......[/go]


I know this one almost by heart ^^ I spend like one hour on it the time I started doing these problems. But I never managed to go over 300. I found the "Graded Go Problems For Beginners" series much more entertaining.

1.
Click Here To Show Diagram Code
[go]$$Bcm1
$$|-------
$$|..152O.
$$|XXOXXO.
$$|4.XOOO.
$$|O3XO...
$$|.OO....
$$|.......[/go]


2a.
Click Here To Show Diagram Code
[go]$$Bcm1
$$|-------
$$|..142O.
$$|XXOXXO.
$$|5.XOOO.
$$|O3XO...
$$|.OO....
$$|.......[/go]


2b.
Click Here To Show Diagram Code
[go]$$Wcm1
$$|-------
$$|..XOOO.
$$|XX12.O.
$$|X.XOOO.
$$|OXXO...
$$|.OO....
$$|.......[/go]


3.
Click Here To Show Diagram Code
[go]$$Bcm1
$$|-------
$$|..1.3O.
$$|XXOXXO.
$$|.2XOOO.
$$|O.XO...
$$|.OO....
$$|.......[/go]



Problem 97
Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|...XO...
$$|.XO.OXX.
$$|.OXO.OX.
$$|..XOOOX.
$$|..XXXX..
$$|........[/go]


Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|341XO...
$$|.XO2OXX.
$$|.OXO.OX.
$$|..XOOOX.
$$|..XXXX..
$$|........[/go]


:b5: at :b1:

Re: Life & Death Encyclopedia Problems

Posted: Thu Aug 05, 2010 1:33 pm
by prokofiev
SoDesuNe wrote:I know this one almost by heart ^^ I spend like one hour on it the time I started doing these problems. But I never managed to go over 300. I found the "Graded Go Problems For Beginners" series much more entertaining.


Uh oh, a dissenting opinion! I'll see how it goes. So far the problems have been nice. I do like the Graded Go Problems For Beginners series quite a bit too. I remember being rather satisfied when I finished volume 3 a while ago. I made it through maybe half of volume 4 back then, too. I should look again at that book, and maybe start at the beginning again, some time.

Re: Life & Death Encyclopedia Problems

Posted: Fri Aug 06, 2010 8:44 pm
by prokofiev
I'm up to 141 now. Some good ones:

Problem 104:
Click Here To Show Diagram Code
[go]$$Bcm1
$$|-------
$$|..OOXO.
$$|.OXXXO.
$$|.OX.XO.
$$|.XOXXO.
$$|..O.OO.
$$|..O....
$$|.......[/go]


Problem 127:
Click Here To Show Diagram Code
[go]$$Bcm1
$$|------
$$|.O.XO.
$$|...XO.
$$|XX.XO.
$$|OX.XO.
$$|OOOOO.
$$|......[/go]


And the "it's an encyclopedia" feel is helped by pairs of problems such as:

Problem 135:
Click Here To Show Diagram Code
[go]$$Bcm1
$$|------
$$|.O....
$$|..OOX.
$$|.OXXX.
$$|.OX...
$$|.XX...
$$|......[/go]


Problem 136:
Click Here To Show Diagram Code
[go]$$Bcm1
$$|------
$$|......
$$|..XXO.
$$|.XOOO.
$$|.X....
$$|.OO...
$$|......[/go]


In case you haven't noticed, it's always black to move. This prevents one from treating the problem as "status" problems, but it's not a big deal.

Other nice ones: 105, 121, 125

142-168, Tripod groups

Posted: Tue Aug 10, 2010 7:48 pm
by prokofiev
I'm up to 168 now. Most of this past set of problems, namely 146-161 or so, have been related to the tripod group (blending into weak L+1 group variations toward the end, but of course that's related).

I'm sure the tripod group arises in many contexts, but here's one I've seen:

Tripod group, as arising from a probe against a low shimari:
Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|........
$$|...1....
$$|.53O2...
$$|..4,....
$$|..O.....
$$|........[/go]


Even though this is quite a few problems, it isn't in any way comprehensive. Both the intermediate and advanced sections have problems on the tripod group in the low-to-mid 100's, it seems.

An example of what one sees in the elementary section:

Problem 151:
Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|..X.....
$$|.O.XO...
$$|.XXOO.O.
$$|..O,....
$$|..O.....
$$|........
$$|..O.....[/go]


One has to wait until the intermediate section for alternatives to the white 2-2 stone (moving it one space to the left is problem 2.133) as well as to go back one ply:

Problem 2.136
Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|........
$$|...XO...
$$|.XXOO...
$$|..O,....
$$|..O.....
$$|........
$$|........[/go]


One does find in the elementary section a "don't do this" follow-up to the above after a descent on the other side as well (147 includes a white stone at 'a' as well):

Problems 146 & 147:
Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|..O.a...
$$|O..OX...
$$|.OOXX.X.
$$|.XX,....
$$|........
$$|........
$$|........[/go]


(147 includes a white stone at 'a' as well)

And one has to wait until the advanced section for a different white challenge:

Problem 3.128:
Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|..O.....
$$|...X....
$$|.XXOO.O.
$$|..O,....
$$|..O.....
$$|........[/go]


Also I noticed the advanced section had one that is mentioned in Davies's Life & Death (the "don't play the push along the 2nd line from the tripod group as then you'll need to defend" idea):

Problem 3.144:
Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|..O.....
$$|...OX...
$$|.OOXX...
$$|.OX,....
$$|.XX.....
$$|........[/go]

169-202

Posted: Mon Aug 16, 2010 9:20 pm
by prokofiev
Up to 202. Some nice ones:

Click Here To Show Diagram Code
[go]$$Bcm1
$$|-------
$$|..XO...
$$|....O..
$$|.XXO...
$$|XXOO...
$$|OO.....
$$|.......
$$|.......[/go]


Click Here To Show Diagram Code
[go]$$Bcm1
$$|-------
$$|.....O.
$$|X..XXO.
$$|OXXO.O.
$$|OOOO...
$$|.......[/go]

Re: Life & Death Encyclopedia Problems

Posted: Tue Aug 17, 2010 2:55 am
by SoDesuNe
Problem 104:
Click Here To Show Diagram Code
[go]$$Bcm1
$$|-------
$$|..OOXO.
$$|.OXXXO.
$$|.OX.XO.
$$|.XOXXO.
$$|..O.OO.
$$|..O....
$$|.......[/go]


Click Here To Show Diagram Code
[go]$$Bcm1
$$|-------
$$|.3WOXO.
$$|.OXXXO.
$$|1OX.XO.
$$|.BOXXO.
$$|..O.OO.
$$|..O....
$$|.......[/go]


White can't throw-in because of liberty shortage due to the marked black stone or :b1:.


Problem 127:
Click Here To Show Diagram Code
[go]$$Bcm1
$$|------
$$|.O.XO.
$$|...XO.
$$|XX.XO.
$$|OX.XO.
$$|OOOOO.
$$|......[/go]


Click Here To Show Diagram Code
[go]$$Bcm1
$$|------
$$|5O4XO.
$$|.1.XO.
$$|XX3XO.
$$|OX2XO.
$$|OOOOO.
$$|......[/go]


Ko (actually it's bent-four-in-the-corner, right? So this should be dead?).

Click Here To Show Diagram Code
[go]$$Bcm1
$$|------
$$|.O3XO.
$$|542XO.
$$|XX.XO.
$$|OX1XO.
$$|OOOOO.
$$|......[/go]


Seki.


Problem 135:
Click Here To Show Diagram Code
[go]$$Bcm1
$$|------
$$|.O....
$$|..OOX.
$$|.OXXX.
$$|.OX...
$$|.XX...
$$|......[/go]


Click Here To Show Diagram Code
[go]$$Bcm1
$$|------
$$|.O.2..
$$|13OOX.
$$|.OXXX.
$$|.OX...
$$|.XX...
$$|......[/go]


Dead due shortage of liberty.

Click Here To Show Diagram Code
[go]$$Bcm1
$$|------
$$|.O.3..
$$|12OOX.
$$|.OXXX.
$$|.OX...
$$|.XX...
$$|......[/go]


Plain dead.


Problem 136:
Click Here To Show Diagram Code
[go]$$Bcm1
$$|------
$$|......
$$|..XXO.
$$|.XOOO.
$$|.X....
$$|.OO...
$$|......[/go]


Click Here To Show Diagram Code
[go]$$Bcm1
$$|------
$$|.1.3..
$$|2.XXO.
$$|.XOOO.
$$|.Xa...
$$|.OO...
$$|......[/go]


This works because of the liberty at 'a'.


Problem 151:
Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|..X.....
$$|.O.XO...
$$|.XXOO.O.
$$|..O,....
$$|..O.....
$$|........
$$|..O.....[/go]


Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|.2X.4...
$$|1O5XO...
$$|.XXOO.O.
$$|.3O,....
$$|..O.....
$$|........
$$|..O.....[/go]


Problem 2.136
Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|........
$$|...XO...
$$|.XXOO...
$$|..O,....
$$|..O.....
$$|........
$$|........[/go]


Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|..32....
$$|.1.XO...
$$|.XXOO...
$$|..O,....
$$|..O.....
$$|........
$$|........[/go]


Ko. I can't find a better result.


Problem 146:
Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|..O.....
$$|O..OX...
$$|.OOXX.X.
$$|.XX,....
$$|........
$$|........
$$|........[/go]


Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|41O53...
$$|O2.OX...
$$|.OOXX.X.
$$|.XX,....
$$|........
$$|........
$$|........[/go]


Problem 147:
Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|..O.O...
$$|O..OX...
$$|.OOXX.X.
$$|.XX,....
$$|........
$$|........
$$|........[/go]


Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|41O5O3..
$$|O2.OX...
$$|.OOXX.X.
$$|.XX,....
$$|........
$$|........
$$|........[/go]


Ko.


Rest later, I got to go. Hope I got those right : )



post scriptum:

Problem 3.128:
Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|..O.....
$$|...X....
$$|.XXOO.O.
$$|..O,....
$$|..O.....
$$|........[/go]


I think this is strange ^^

Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|41O5....
$$|a23X....
$$|.XXOO.O.
$$|..O,....
$$|..O.....
$$|........[/go]


If White fills at :b1: Black 'a' allows two ways to get a second eye.

Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|.1O23...
$$|..5X4...
$$|.XXOO.O.
$$|..O,....
$$|..O.....
$$|........[/go]


Also two ways to get two eyes.



Problem 3.144:
Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|..O.....
$$|...OX...
$$|.OOXX...
$$|.OX,....
$$|.XX.....
$$|........[/go]


Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|.5O43...
$$|12.OX...
$$|.OOXX...
$$|.OX,....
$$|.XX.....
$$|........[/go]


Ko.


Click Here To Show Diagram Code
[go]$$Bcm1
$$|-------
$$|..XO...
$$|....O..
$$|.XXO...
$$|XXOO...
$$|OO.....
$$|.......
$$|.......[/go]


Click Here To Show Diagram Code
[go]$$Bcm1
$$|-------
$$|.3XO...
$$|1524O..
$$|.XXO...
$$|XXOO...
$$|OO.....
$$|.......
$$|.......[/go]


Click Here To Show Diagram Code
[go]$$Bcm1
$$|-------
$$|.....O.
$$|X..XXO.
$$|OXXO.O.
$$|OOOO...
$$|.......[/go]


Click Here To Show Diagram Code
[go]$$Bcm1
$$|-------
$$|.3245O.
$$|X17XXO.
$$|OXXO6O.
$$|OOOO...
$$|.......[/go]


Click Here To Show Diagram Code
[go]$$Bcm1
$$|-------
$$|72354O.
$$|X1.XXO.
$$|OXXO6O.
$$|OOOO...
$$|.......[/go]


Click Here To Show Diagram Code
[go]$$Bcm1
$$|-------
$$|.5423O.
$$|X17XXO.
$$|OXXO6O.
$$|OOOO...
$$|.......[/go]

Re: Life & Death Encyclopedia Problems

Posted: Tue Aug 17, 2010 5:15 am
by Marcus
SoDesuNe wrote:Problem 104:
Click Here To Show Diagram Code
[go]$$Bcm1
$$|-------
$$|..OOXO.
$$|.OXXXO.
$$|.OX.XO.
$$|.XOXXO.
$$|..O.OO.
$$|..O....
$$|.......[/go]


Click Here To Show Diagram Code
[go]$$Bcm1
$$|-------
$$|.3WOXO.
$$|.OXXXO.
$$|1OX.XO.
$$|.BOXXO.
$$|..O.OO.
$$|..O....
$$|.......[/go]


White can't throw-in because of liberty shortage due to the marked black stone or :b1:.


What about this?

Click Here To Show Diagram Code
[go]$$Bcm1
$$|-------
$$|23WOXO.
$$|.OXXXO.
$$|1OX.XO.
$$|.BOXXO.
$$|..O.OO.
$$|..O....
$$|.......[/go]


Click Here To Show Diagram Code
[go]$$Bcm1
$$|-------
$$|2.4.XO.
$$|.OXXXO.
$$|1OX.XO.
$$|.BOXXO.
$$|..O.OO.
$$|..O....
$$|.......[/go]

Re: Life & Death Encyclopedia Problems

Posted: Tue Aug 17, 2010 5:59 am
by SoDesuNe
Right, my answer is wrong.

Click Here To Show Diagram Code
[go]$$Bcm1
$$|-------
$$|..OOXO.
$$|1OXXXO.
$$|.OX.XO.
$$|.XOXXO.
$$|..O.OO.
$$|..O....
$$|.......[/go]


This should work.

Re: Life & Death Encyclopedia Problems

Posted: Tue Aug 17, 2010 1:05 pm
by prokofiev
SoDesuNe wrote:Problem 127:
Click Here To Show Diagram Code
[go]$$Bcm1
$$|------
$$|.O.XO.
$$|...XO.
$$|XX.XO.
$$|OX.XO.
$$|OOOOO.
$$|......[/go]


Click Here To Show Diagram Code
[go]$$Bcm1
$$|------
$$|5O4XO.
$$|.1.XO.
$$|XX3XO.
$$|OX2XO.
$$|OOOOO.
$$|......[/go]


Ko (actually it's bent-four-in-the-corner, right? So this should be dead?).

Click Here To Show Diagram Code
[go]$$Bcm1
$$|------
$$|.O3XO.
$$|542XO.
$$|XX.XO.
$$|OX1XO.
$$|OOOOO.
$$|......[/go]


Seki.



The "failure" diagram you have is ko, not dead, because the ko is active. The following would just be dead under Japanese rules (and most likely just dead under other rules unless there are large enough unremovable ko threats):

Click Here To Show Diagram Code
[go]$$Bcm1
$$|------
$$|OOOXO.
$$|aX.XO.
$$|XXXXO.
$$|OXOXO.
$$|OOOOO.
$$|......[/go]


(The idea being that white can turn it into a bent-four ko fight at the end of the game when (or rather if) there are few enough ko threats around by playing at 'a'.)



SoDesuNe wrote:Problem 2.136
Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|........
$$|...XO...
$$|.XXOO...
$$|..O,....
$$|..O.....
$$|........
$$|........[/go]


Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|..32....
$$|.1.XO...
$$|.XXOO...
$$|..O,....
$$|..O.....
$$|........
$$|........[/go]


Ko. I can't find a better result.


Try 1 elsewhere:

Try 1 at 3. Then there are various white responses to read out.

In one of the other problems you read out one white response. In another you saw what not to do after a different white response. I mentioned a third white response being Problem 2.133 in my post above.

Re: Life & Death Encyclopedia Problems

Posted: Tue Aug 17, 2010 1:34 pm
by SoDesuNe
prokofiev wrote:
Try 1 elsewhere:

Try 1 at 3. Then there are various white responses to read out.

In one of the other problems you read out one white response. In another you saw what not to do after a different white response. I mentioned a third white response being Problem 2.133 in my post above.


I did try other first moves, but it didn't change the result in favour for Black. At least, so I read this ^^

Re: Life & Death Encyclopedia Problems

Posted: Tue Aug 17, 2010 1:44 pm
by prokofiev
SoDesuNe wrote:I did try other first moves, but it didn't change the result in favour for Black. At least, so I read this ^^


What is it you read there being for White after:

Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|..1.....
$$|...XO...
$$|.XXOO...
$$|..O,....
$$|..O.....
$$|........
$$|........[/go]


(Or maybe I misunderstand your "so I read this" :) )

Re: Life & Death Encyclopedia Problems

Posted: Tue Aug 17, 2010 2:11 pm
by SoDesuNe
prokofiev wrote:
SoDesuNe wrote:I did try other first moves, but it didn't change the result in favour for Black. At least, so I read this ^^


What is it you read there being for White after:

Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|..1.....
$$|...XO...
$$|.XXOO...
$$|..O,....
$$|..O.....
$$|........
$$|........[/go]


(Or maybe I misunderstand your "so I read this" :) )



Click Here To Show Diagram Code
[go]$$Bcm1
$$|--------
$$|5.142...
$$|.3.XO...
$$|.XXOO...
$$|..O,....
$$|..O.....
$$|........
$$|........[/go]


I think, this is the best White/Black can get. :w2: at :b3: leads to problem 151, thus Black lives.