Life In 19x19

Dear Bill,

Bill Spight wrote:As I have said, chunking occurs automatically, and my suspicion is that White learned this chunk automatically, and, as a result, incorrectly.

Perhaps your conclusion is a bit over-hasty ?

In the problem Black cannot play because of damezumari. The three stones have at that point only 2 dame.

This is undoubtedly correct. However, ...

White should have learned the dame count as part of the chunk.

... how could White have gained this knowledge in the absense of further examples (for study) ?

Learning that kind of thing is not all that likely to happen with automatic chunking, which is why I talk about chunking in the context of sub-problems and subgoals, and why I talk about understanding.

Again, this is undoubtedly correct. Repetition matters !!!
E.g.

Click Here To Show Diagram Code

[go]$$B Zero liberties
$$ --------------------
$$ | O . . . O X . . .
$$ | O . O O O X . . .
$$ | O O O X X X . . .
$$ | X X X X . . . . .
$$ | . . . . . . . . .[/go]

vs.

Click Here To Show Diagram Code

[go]$$B Zero liberties
$$ ------------------
$$ | . . . O X . . .
$$ | . O O O X . . .
$$ | O O X X X . . .
$$ | X X X . . . . .
$$ | . . . . . . . .[/go]

Click Here To Show Diagram Code

[go]$$B One liberty
$$ ------------------
$$ | . . . O . . . .
$$ | . O O O X . X .
$$ | O O X X X . . .
$$ | X X X . . . . .
$$ | . . . . . . . .[/go]

Click Here To Show Diagram Code

[go]$$B Two liberties
$$ ------------------
$$ | . . . O . . . .
$$ | . O O O X . X .
$$ | O O X X X . . .
$$ | . X X . . . . .
$$ | . . . . . . . .
$$ | . X . . . . . .
$$ | . . . . . . . .[/go]

BTW, the extra dame is what psychologists call a just noticeable difference (JND). If you use flashcards for training, I recommend making flashcards with JNDs from the original problem or position, to avoid making the kind of mistake that White made in a real game.

Good idea. Its application could be extended to cases, where several stones that are in atari (or could be put in atari) are only on the tsume-go board to bedazzle your mind

Accidental duplicate.

This space left intentionally blank.

Bill Spight wrote:Or vice versa, given your research into tsumego.

OK, "chunking" / "shape analysis" matures over time

$$B Black to play and kill
$$ -------------------------------
$$ . . . . O . 1 . . . . . . . . .
$$ . . . X O O . O O O . . B . ? ?
$$ . . X . X O O X O X . X . . . .
$$ . . . . X X X X X X . . X . . .
$$ . . . . . . . . . . . . . . . .
$$ . . . . . . . . . . . . . . . .

Click Here To Show Diagram Code

[go]$$B Black to play and kill
$$ -------------------------------
$$ . . . . O . 1 . . . . . . . . .
$$ . . . X O O . O O O . . B . ? ?
$$ . . X . X O O X O X . X . . . .
$$ . . . . X X X X X X . . X . . .
$$ . . . . . . . . . . . . . . . .
$$ . . . . . . . . . . . . . . . .[/go]

My feeling is, if this position occurred in a game between you and me, we would stop local play after , without giving it much thought. The stone is just too close for White to live.

Probably White might want to establish one of her stones in the shadowed area ?

My impression is that, as life and death problems become more difficult, damezumari looms larger. What do you think?

Yes, indeed. Damezumari is one of the somewhat "problematic" issues, because it depends on the visualisation of stones that will be played in the future.
The "under-the-stones"-issue is another one, as is sacrifycing own stones for spoiling your opponent's shape.

I think that tsume-go usually are considered to be "more difficult", the larger the potential eye space and the "more open" the position is.

RobertJasiek wrote:But from the possibility of different players using different chunks follows that demonstrations need a) much abstraction to then be applicable by different players or b) explanations for usage by one particular player presented in a manner so that everybody else can construct and derive application for different chunks and usage details.

I do not consider a) being the "best" kind of presentation.

I like b) more. Supply the student with a lot of suitable examples and let him / her derive their own "rules".
Every "rule" has its exeptions, and it will benefit the student to know THEIR exceptions for THEIR "rules".

However, creating this set of examples might be very time-consuming, boring and exhaustive for the author

Bill Spight wrote:Verifying a solution means that for each play by the solver, an answer must be found for every possible reply by the opponent.

No. Such would be the brute force verification. Verifications can be much lighter.

Cassandra wrote:creating this set of examples might be very time-consuming, boring and exhaustive for the author

I know. Therefore you do not supply some with sufficient details yet. Random hint:

Click Here To Show Diagram Code

[go]$$W
$$ -----------------------------------
$$ . . . . O . X X . O . X O 1 . . O .
$$ . . . X O O . O O O O O X . . . . O
$$ . . X . X O O X O X . X . . . . . .
$$ . . . . X X X X X X . . X . . . . .
$$ . . . . . . . . . . . . . . . . . .
$$ . . . . . . . . . . . . . . . . . .[/go]

Cassandra wrote:Dear Bill,

Bill Spight wrote:As I have said, chunking occurs automatically, and my suspicion is that White learned this chunk automatically, and, as a result, incorrectly.

Perhaps your conclusion is a bit over-hasty ?

In the problem Black cannot play because of damezumari. The three stones have at that point only 2 dame.

This is undoubtedly correct. However, ...

White should have learned the dame count as part of the chunk.

... how could White have gained this knowledge in the absense of further examples (for study) ?

By asking why Black cannot play below, which would live.

Click Here To Show Diagram Code

[go]$$W Kill!
$$ ---------------------
$$ | . . X 2 1 . . . . .
$$ | X X . 3 4 O . . . .
$$ | O O X X X O . . . .
$$ | . . O O O O . . . ,
$$ | . O . . . . . . . .
$$ | . . . . . . . . . .
$$ | . . . . . . . . . .[/go]

Also, if the player already has the concept of a half eye, he could add this position to the collection of half eyes.

Click Here To Show Diagram Code

[go]$$W Half eye
$$ ---------------------
$$ | . . B B W . . . . .
$$ | X B . . . W . . . .
$$ | O W B B B W . . . .
$$ | . . W W W O . . . ,
$$ | . O . . . . . . . .
$$ | . . . . . . . . . .
$$ | . . . . . . . . . .[/go]

With a little thought he could add this position, as well.

Click Here To Show Diagram Code

[go]$$W Half eye
$$ ---------------------
$$ | . . B B W W . . . .
$$ | X B . . B W . . . .
$$ | O W B B . W . . . .
$$ | . . W W W O . . . ,
$$ | . O . . . . . . . .
$$ | . . . . . . . . . .
$$ | . . . . . . . . . .[/go]

This half eye frequently occurs in life and death problems. The key play to take away the potential eye is the same.

Click Here To Show Diagram Code

[go]$$W Half eye
$$ ---------------------
$$ | . . B B . W . . . .
$$ | X B . . . W . . . .
$$ | O W B B . W . . . .
$$ | . . W W W O . . . ,
$$ | . O . . . . . . . .
$$ | . . . . . . . . . .
$$ | . . . . . . . . . .[/go]

And here is another one.

Edit:

Click Here To Show Diagram Code

[go]$$W Half eye
$$ ---------------------
$$ | . . B . . W . . . .
$$ | X B . . B W . . . .
$$ | O W B B . W . . . .
$$ | . . W W W O . . . ,
$$ | . O . . . . . . . .
$$ | . . . . . . . . . .
$$ | . . . . . . . . . .[/go]

And another one.

RobertJasiek wrote:

Bill Spight wrote:Verifying a solution means that for each play by the solver, an answer must be found for every possible reply by the opponent.

No. Such would be the brute force verification. Verifications can be much lighter.

One of the things that makes it lighter is the utilization of chunks.

RobertJasiek wrote:

Cassandra wrote:creating this set of examples might be very time-consuming, boring and exhaustive for the author

I know. Therefore you do not supply some with sufficient details yet. Random hint:

$$W
$$ -----------------------------------
$$ . . . . O . X X . O C B O 1 . . O .
$$ . . . X O O . O O O O O X . . . . O
$$ . . X . X O O X O X . X . . . . . .
$$ . . . . X X X X X X . . X . . . . .
$$ . . . . . . . . . . . . . . . . . .
$$ . . . . . . . . . . . . . . . . . .

Click Here To Show Diagram Code

[go]$$W
$$ -----------------------------------
$$ . . . . O . X X . O C B O 1 . . O .
$$ . . . X O O . O O O O O X . . . . O
$$ . . X . X O O X O X . X . . . . . .
$$ . . . . X X X X X X . . X . . . . .
$$ . . . . . . . . . . . . . . . . . .
$$ . . . . . . . . . . . . . . . . . .[/go]

That's from a different problem.

But 1) it does not invalidate the assertion that takes away the distinct eye at , and 2) it gives me the excuse to do what I had in mind, which was to show continuations after in the main line.

Click Here To Show Diagram Code

[go]$$Wm10 Continuation
$$ -----------------------------------
$$ . . . . O . X X . O . X O 1 3 . . .
$$ . . . X O O . O O O O O X 2 . . . .
$$ . . X . X O O X O X . X . . . . . .
$$ . . . . X X X X X X . . X . . . . .
$$ . . . . . . . . . . . . . . . . . .
$$ . . . . . . . . . . . . . . . . . .[/go]

White has a "ladder".

Click Here To Show Diagram Code

[go]$$Wm10 Net
$$ -----------------------------------
$$ . . . . O . X X . O . X O 1 3 . . .
$$ . . . X O O . O O O O O X 2 . 4 . .
$$ . . X . X O O X O X . X . . . . . .
$$ . . . . X X X X X X . . X . . . . .
$$ . . . . . . . . . . . . . . . . . .
$$ . . . . . . . . . . . . . . . . . .[/go]

Or a net.

Bill Spight wrote:And another one.

As I already wrote, your chunks are larger than mine

BTW. Your "half-eye"-problems are a beautiful confirmation that my idea "let players derive their own rules" has some merits.

RobertJasiek wrote:I know. Therefore you do not supply some with sufficient details yet. Random hint:

Problems that ask for the status of a group are NO part of my work.

Additionally, Bill's problem is out of range of my current activity. Currently, I am still busy with one-move life-and-death-problems (not very acute; you know -- the boring effect), due to the backlash of failure variations in three- and five-move problems.

Cassandra wrote:

Bill Spight wrote: My impression is that, as life and death problems become more difficult, damezumari looms larger. What do you think?

Yes, indeed. Damezumari is one of the somewhat "problematic" issues, because it depends on the visualisation of stones that will be played in the future.
The "under-the-stones"-issue is another one, as is sacrificing own stones for spoiling your opponent's shape.

Good point. A lot of people have a blind spot about under the stones play.

Speaking of which:

Click Here To Show Diagram Code

[go]$$B
$$ -------------------------------
$$ . . . . O . B B B . W . . . . .
$$ . . . X O O . O O O W . X . . .
$$ . . X . X O O X O X . X . . . .
$$ . . . . X X X X X X . . X . . .
$$ . . . . . . . . . . . . . . . .
$$ . . . . . . . . . . . . . . . .[/go]

Black made a mistake in the original problem and left behind this seki, right?

Hint:

Cassandra wrote:[
Problems that ask for the status of a group are NO part of my work.

But in terms of improving your play, those are the most important.

Ideally you are working on may types of problems at the same time. Ones hard enough to challenge your reading ability even though you are told the goal are good for building reading skills. Ones that are somewhat easier, that knowing the goal you can solve in the amount of time you could afford to spend in a game DO help your play in under some special situations*. But even easier ones that you can solve at that speed WITHOUT knowing the status (CAN that group be killed, CAN that group live even though the other player moves first -- and if so, live with points, live in seki, ko) are what will most improve your game.

Remember, as a practical matter, can be very important to correctly decide "is that move senti?"

* example -- a quick count shows that you will lose the game unless either one of the opponent's not quite safe yet groups can be killed --- then you can analyze based on "kill" because the alternative is "resign"

In relation to Bill's problem:

Mike Novack wrote:

Cassandra wrote:[
Problems that ask for the status of a group are NO part of my work.

But in terms of improving your play, those are the most important.

May be, but those cannot be often found in Go books.

Additionally, problems that ask for the status of a group can be clustered into
A) Black to live, Black to kill (colours reversed)
B) Black is alive
C) Black is dead

A) is by far the most interesting section for writing a book about tsume-go, concentrating especially on shape issues and vital points.

B) and C) can be left for life-and-death dictionaries, or for books that aim at showing the impact of life-and-death on practical play. Problems of this cluster are not really suitable for studying vital shape points, just because there is nothing that you can do (probably with the exception of looking for the best endgame sequence included).

In my book on one-move problems, I tried to "mirror" every problem (life <> death). However, this is not practical in every case. Sometimes "Black to kill" is too trivial as to be really valuable. More often, reaching either "life" (exclusive) or "death" needs more than one move, and so has to be kept in reserve for future usage.

(Basic) Shapes of the "zero-move" kind that are part of the B) / C) cluster are also explained in my book, for the sake of completeness.