This 'n' that

Bill Spight · **#201**

Let's tackle the harder problem first.

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

It is not obvious, but Black has 1.25 eyes, 0.5 of an eye on the side and 0.75 of an eye in the corner, and has to make another 0.75 of an eye to live. She does this by making 1.5 eyes in the corner.

Click Here To Show Diagram Code: [go]$$B Black to play and live $$ -------------------- $$ . . . . 4 . 5 . W . | $$ . . O 6 1 O O 3 . . | $$ . . . O 2 X X X X X | $$ , . . . O O O O O X | $$ . . . . . . . . X . | $$ . . . . O . X X . . | $$ . . . . . . X O X . | $$ . . . . O . X O X . | $$ . . . . . O O O O O | $$ , . . . . . , . . . | $$ . . . . . . . . . . |[/go]

Stage 1 is to get :b3:

and

in place in sente, threatening the :wc:

stone.

Click Here To Show Diagram Code: [go]$$B Variation $$ -------------------- $$ . . . . 7 6 5 4 W . | $$ . . O . 1 O O 3 . . | $$ . . . O 2 X X X X X | $$ , . . . O O O O O X | $$ . . . . . . . . X . | $$ . . . . O . X X . . | $$ . . . . . . X O X . | $$ . . . . O . X O X . | $$ . . . . . O O O O O | $$ , . . . . . , . . . | $$ . . . . . . . . . . |[/go]

White cannot afford to play atari at 4.

Click Here To Show Diagram Code: [go]$$B Life $$ -------------------- $$ . . . . O . X . W 7 | $$ . . O O . O O X a . | $$ . . . O O X X X X X | $$ , . . . O O O O O X | $$ . . . . . . . . X . | $$ . . . . O . X X . . | $$ . . . . . . X O X . | $$ . . . . O . X O X . | $$ . . . . . O O O O O | $$ , . . . . . , . . . | $$ . . . . . . . . . . |[/go]

Black now has and a half eyes in the corner. Added to the half eye on the side gives two eyes for life. ( :b7:

could also be at "a".) Why one and a half eyes?

Click Here To Show Diagram Code: [go]$$W One eye $$ -------------------- $$ . . . . O . X 1 O X | $$ . . O O . O O X 2 . | $$ . . . O O X X X X X | $$ , . . . O O O O O X | $$ . . . . . . . . X . | $$ . . . . O . X X . . | $$ . . . . . . X O X . | $$ . . . . O . X O X . | $$ . . . . . O O O O O | $$ , . . . . . , . . . | $$ . . . . . . . . . . |[/go]

throws in at 1.

White can hold Black to one eye in the corner in gote.

Click Here To Show Diagram Code: [go]$$B Two eyes $$ -------------------- $$ . . . . O . X 3 O X | $$ . . O O . O O X 1 2 | $$ . . . O O X X X X X | $$ , . . . O O O O O X | $$ . . . . . . . . X . | $$ . . . . O . X X . . | $$ . . . . . . X O X . | $$ . . . . O . X O X . | $$ . . . . . O O O O O | $$ , . . . . . , . . . | $$ . . . . . . . . . . |[/go]

Black to play can make two eyes in the corner by oshitsubushi, also in gote.

Click Here To Show Diagram Code: [go]$$B Book solution $$ -------------------- $$ . . . . O . X . W 7 | $$ . . O O . O O X 8 . | $$ . . . O O X X X X X | $$ , . . . O O O O O X | $$ . . . . . . . . X . | $$ . . . . O . X X . . | $$ . . . . . . X O X . | $$ . . . . O . X O X . | $$ . . . . . O O O O O | $$ , . . . . . , . . . | $$ . . . . . . . . . . |[/go]

In the book White played :w8:

. Black gets 5 points in the corner instead of 3, but still she has only one eye.

Click Here To Show Diagram Code: [go]$$B Under the stones $$ -------------------- $$ . . . . O . X O . X | $$ . . O O . O O X X . | $$ . . . O O X X X X X | $$ , . . . O O O O O X | $$ . . . . . . . 7 X 3 | $$ . . . . O . X X 4 2 | $$ . . . . . . X O X 5 | $$ . . . . O . X O X 1 | $$ . . . . . O O O O O | $$ , . . . . . , . . . | $$ . . . . . . . . . . |[/go]

throws in at 4. :w8:

at 2 captures four stones.

After White holds Black to one eye in the corner Black has to pick up half an eye on the side. She does this by an under the stones sacrifice, which is familiar to experienced tsumego solvers.

Click Here To Show Diagram Code: [go]$$B Second eye $$ -------------------- $$ . . . . O . X O . X | $$ . . O O . O O X X . | $$ . . . O O X X X X X | $$ , . . . O O O O O X | $$ . . . . . . . X X X | $$ . . . . O . X X W W | $$ . . . . . . X O 9 . | $$ . . . . O . X O . . | $$ . . . . . O O O O O | $$ , . . . . . , . . . | $$ . . . . . . . . . . |[/go]

captures the :wc:

stones to make the second eye.

I don't know whether Kobayashi père composed this problem or whether it is a famous ancient problem, but it is pretty cool, isn't it?

Despite the slight flaw of :w8:

. First Black encloses the White stone in the corner in sente, with a throw-in if White tries to connect. Then Black makes one and a half eyes with the 1-1 play, threatening to make two eyes with oshitsubushi. And finally Black plays an under the stones sacrifice to pick up half an eye on the side. Poetic!

Bill Spight · **#202**

I'm back!

I just ran across a nice opening problem in an ancient game.

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

It's easy.

At least if you have seen this kind of play before.

Enjoy!

EdLee · **#203**

Uberdude · **#204**

A while ago..

Kirby wrote:

If it were my game, I'd first try to make white heavy with a peep, and then I'd take territory on the bottom.

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

There are other moves that might give more pressure to black, but I don't seem to have a clear plan as to how to follow up:

Kirby, I thought of you when Ali Jabarin 1p played move 68 in this KGS game today

:

Bill Spight · **#205**

Ed got it right.

Click Here To Show Diagram Code: [go]$$Bcm23 Last big play? $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . O . . X . . . . | $$ | . . O , . O . O . , . . . . . , X . . | $$ | . . X X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . O X X . . . . . . . . . . . . . . . | $$ | . . O . X . . . . . . . . . . . X . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . 1 . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X , . . . . . , . . . . . , . . . | $$ | . . . . . X . . . . X . O . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

When I was 4 kyu, I think that I probably would have played :b23:

, as the last big play of the opening. But that is lackadaisical thinking.

The game was played in 1802 between Yasui Chitoku (W) and Sato Shunsaku. Sato played :b23:

, below.

Click Here To Show Diagram Code: [go]$$Bcm23 Yasui Chitoku (W) - Sato Shunsaku $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . O . . X . . . . | $$ | . . O , . O . O . , . . . . . , X . . | $$ | . . X X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . 5 . . . . . . . . . . . . . . . . . | $$ | . O X X . . . . . . . . . . . . . . . | $$ | . 6 O . X . . . . . . . . . . . X . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . 4 3 . . . . . . . . . . . . . . . | $$ | . . O . 2 . . . . . . . . . . . 7 . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . 1 . . . . . . . . . . . . . O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X , . . . . . , . . . . . , . . . | $$ | . . . . . X . . . . X . O . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Although

is only a one space extension, it is a dual purpose play, making territory while attacking the White group on the left side. Chitoku jumped out with :w24:

. Sato continued the attack with :b25:

and

, and still got the two space extension at :b29:

.

The game record:

Bill Spight · **#206**

Here is another Chitoku game, a castle game vs. Honinbo Retsugen (W)

Click Here To Show Diagram Code: [go]$$Bm31 Retsugen (W) - Chitoku $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . . X X . X . . . . . . O X . X . | $$ | . X X , X O O 1 . , . . . O O , X . . | $$ | . X O O O . . . . . . . O X . X . . . | $$ | . . . . . . . . . . . . O X . . . . . | $$ | . . O . . . . . . . . . . O . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O . 6 . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . X , 2 . . | $$ | . . . O . . . . . 4 . 5 . . . . 3 . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

I confess that I would have missed :b31:

. It is a thick play that counters White's thickness. Not much happens on the top side for some time, now.

Retsugen plays :w32:

in the bottom right corner and then, after :b33:

, is satisfied to have prevented Black from making an ideal enclosure, and takes the big point at :w34:

. Skillful play.

Chitoku contents himself with the extension to :b35:

, and then Retsugen jumps to :w36:

, a big whole board move.

Click Here To Show Diagram Code: [go]$$Bcm37 What now? $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . . X X . X . . . . . . O X . X . | $$ | . X X , X O O X . , . . . O O , X . . | $$ | . X O O O . . . . . . . O X . X . . . | $$ | . . . . . . . . . . . . O X . . . . . | $$ | . . O . . . . . . . . . . O . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O . O . . . 7 . . . . . . . . . . | $$ | . . . . . . . . 5 6 . . . . . . . . . | $$ | . . . 4 . . . . 1 2 . . . . X , O . . | $$ | . . . O 3 . . . . O . X . . . . X . . | $$ | . . . . . . . 8 . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Chitoku makes the standard reducing play at :b37:

and then takes kikashi in the corner before extending towards the center.

Where did Chitoku play next? (FWIW, I think that it is the only play.

)

Enjoy!

EdLee · **#207**

Hi Bill,

bayu · **#208**

first a question: why is blocking instead of 32 not good/inferior? It would defend the cutting point. Is it because the thickness is not that good with the open skirt and that white would expose the cut at N16? Or is it that black gets a great point elsewhere?

As for your question:

Bill Spight · **#209**

bayu wrote:

first a question: why is blocking instead of 32 not good/inferior? It would defend the cutting point. Is it because the thickness is not that good with the open skirt and that white would expose the cut at N16? Or is it that black gets a great point elsewhere?

Well, I missed :b31:

, so I don't know if I am the person to ask about the block. But the cut at F-15 is no big deal. White can just sacrifice two stones. And the bottom looks big to me at this point. FWIW.

Bill Spight · **#210**

bayu got it right.

Click Here To Show Diagram Code: [go]$$Bcm45 Central turn $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . . X X . X . . . . . . O X . X . | $$ | . X X , X O O X . , . . . O O , X . . | $$ | . X O O O . . . . . . . O X . X . . . | $$ | . . . . . . . . . . . . O X . . . . . | $$ | . . O . . . . . . . . . . O . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . 9 . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O . O . . . X 1 . . . . . . . . . | $$ | . . . . . . . . X O . 4 . . . . . . . | $$ | . . . O . . . . X O . 2 3 . X , O . . | $$ | . . . O X . . . 5 O . X . . . . X . . | $$ | . . . . . . . O 6 8 7 a . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

The central turn, :b45:

, is big. After White's attach-and-extend Black takes kikashi with :b49:

and

, which prevents the White clamp at "a". Then :b53:

jumps into the center.

Here is the game record.

Bill Spight · **#211**

Now, at long last, the easy problem from Igo Tsumekata.

Click Here To Show Diagram Code: [go]$$W White to play and kill $$ ---------------- $$ . . . . . . . . | $$ . . O O X . . . | $$ . . O X . X . . | $$ . . O X , X X . | $$ . . . O . O O . | $$ . . . O . . . . | $$ . . . . . O . . | $$ . . . . . . . . | $$ . . . . . . . . |[/go]

The first play is kind of obvious.

Click Here To Show Diagram Code: [go]$$W White to play and kill $$ ---------------- $$ . . . . . . . . | $$ . . O O X 2 1 . | $$ . . O X . X . . | $$ . . O X 3 X X . | $$ . . . O . O O . | $$ . . . O . . . . | $$ . . . . . O . . | $$ . . . . . . . . | $$ . . . . . . . . |[/go]

If

,

leaves a dead shape in the corner, which is familiar to experienced players.

Click Here To Show Diagram Code: [go]$$W Dieter's hane $$ ---------------- $$ . . . 6 3 4 7 . | $$ . . O O X 5 1 . | $$ . . O X a X . . | $$ . . O X 2 X X . | $$ . . . O . O O . | $$ . . . O . . . . | $$ . . . . . O . . | $$ . . . . . . . . | $$ . . . . . . . . |[/go]

If

,

is Dieter's hane. Black can prevent the connection, but at the cost of the eye at "a". This is the line in the book.

----

Practical problems?

I like this problem because I think that it is practical. Not that it will occur as is in any game, but the idea is important and easy to grasp.

There is a school of thought that the best problems are the practical ones, those that come up in real games or are similar to positions that do. That is one reason that it is good to study your own games. The problems that they present are definitely practical.

But I also like the idea of thoroughly understanding positions in limited regions of play; like the 7 point corner in the first variation. Now, that position is a practical one to know. But what about this position?

Click Here To Show Diagram Code: [go]$$B Nim anyone? (Outer stones alive) $$ ------------------- $$ . . X O . . X O . . $$ . . X X X O O O . . $$ . . . . . . . . . .[/go]

There is a certain charm to the play on these four points. And yes, it is related to the game of Nim.

I was pleased to discover it a few years ago.

But that is the thing. I discovered it. I have never seen the like in a game, nor do I expect to. And even if it were to occur in a game, the chance that knowing how to play it would be crucial is miniscule. I do think that there is some practical value in seeing the under the stones possibilities, though.

EdLee · **#212**

Hi Bill, Thanks for posting these.

Bill Spight · **#213**

I think that Igo Tsumekata ( http://dl.ndl.go.jp/info:ndljp/pid/861034/36 ) has a lot of practical problems, most of them at the kyu level. However, to read the answers in the text it helps to know the Chinese numerals.

With that caveat I can recommend the book.

Here is an easy one. And practical, I think.

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

Enjoy!

EdLee · **#214**

EdLee · **#215**

Bill Spight wrote:

to read the answers in the text it helps to know the Chinese numerals.

Hi Bill,

The Arabic numerals were an excellent invention.

Do you happen to know when this book was originally published ?

Very practical -- Thanks.

Bill Spight · **#216**

EdLee wrote:

Do you happen to know when this book was originally published ?

It was part of a set published in 1901. The father died in 1893. I don't know if there was an earlier edition.

jeromie · **#217**

Without peeking at Ed's answer, here's my solution. That's a nice problem!

Bill Spight · **#218**

Here is a problem that appears in several sources.

Click Here To Show Diagram Code: [go]$$B Black invasion, I $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . 5 4 6 . . . . . . . . . . . . . . . | $$ | . . 1 2 . . . . . . . . . . . . . . . | $$ | . . 3 O . . . . . , . . . . . , . . . | $$ | . . 7 8 . . . . . . . . . . . . . . . | $$ | . 9 O . . . . . . . . . . . . . . . . | $$ | . 0 . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . |[/go]

For background, say that Black invades the top left White corner. :w10:

plays a two step hane.

Click Here To Show Diagram Code: [go]$$Bm11 Black invasion, II $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . X O O . . . . . . . . . . . . . . . | $$ | . . X O . . . . . . . . . . . . . . . | $$ | . . X O . . . . . , . . . . . , . . . | $$ | . . X O . . . . . . . . . . . . . . . | $$ | 1 X O . . . . . . . . . . . . . . . . | $$ | . O 2 . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . |[/go]

descends to the first line, and :w12:

connects.

Suppose that Black now tenukis. That yields the problem position. Modern versions strengthen White on the left side, to keep Black contained. Let's do that for the problem diagram.

Click Here To Show Diagram Code: [go]$$B White to play $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . X O O . . . . . . . . . . . . . . . | $$ | . . X O . . . . . . . . . . . . . . . | $$ | . . X O . . . . . , . . . . . , . . . | $$ | . . X O . . . . . . . . . . . . . . . | $$ | X X O . . . . . . . . . . . . . . . . | $$ | . O O . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . |[/go]

White to play in the top left corner, with what result?

Enjoy!

EdLee · **#219**

Bill Spight wrote:

It was part of a set published in 1901. The father died in 1893.

Hi Bill,

Just curious: how did you come across this set (and the website) ?
I see a Mr. Kobayashi (?) and his son(?); was he/were they pro ?
Or Honinbo or other title holders ?

EdLee · **#220**

This 'n' that

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