Life In 19x19

Posted: **Thu Oct 11, 2012 2:03 am**

HermanHiddema wrote:So these players do not consider every line of play

The same applies to logical players.

And they are not weaker players for it.

This conclusion is not justified by your arguments so far.

Posted: **Thu Oct 11, 2012 2:16 am**

RobertJasiek wrote:
And they are not weaker players for it.

This conclusion is not justified by your arguments so far.

Let me rephrase that, because you seem to be taking it a little bit too literally:

They are not weak players, despite failing to solve small space problems which could logically be solved by systematically going through the very small number of lines of play.

Posted: **Thu Oct 11, 2012 3:34 am**

I solved it in about a minute, but that was basically by applying all possible moves and follow up moves. I suspect I would not have solved it in a game, because it wouldn't have occurred to me to check - intuitively it looks dead. Here I did because I knew there was a solution.

Posted: **Thu Oct 11, 2012 4:32 am**

quantumf, there is always a solution even if it is trivial!

Posted: **Thu Oct 11, 2012 5:06 am**

RobertJasiek wrote:quantumf, there is always a solution even if it is trivial!

I don't understand your reply, Robert. What I'm saying is that tsumego's encourage looking for a solution, because they are tsumegos and you KNOW there is a solution. Similar shapes in actual games may end up being ignored - because they are "obviously" alive, or dead.

Posted: **Thu Oct 11, 2012 11:58 am**

Basically he is saying that there is always a slightly better way to die, and a slightly worse way to die, which really isn't relevant.

Posted: **Thu Oct 11, 2012 7:12 pm**

HermanHiddema wrote:
And these same strong kyu players were able to solve a problem like this:

$$W White to play and kill.
$$ +------------------
$$ | . . X O . . . . .
$$ | . . . X O . O . .
$$ | . O . X O . . . .
$$ | X X X X O . . . .
$$ | . O O O O . . . .
$$ | . . . . . . . . .
$$ | . O . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .

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

Which has many more points to consider, and a much longer main line.

So these players do not consider every line of play, even in a very small space. They consider only moves which they find intuitive. At some fundamental level, they do not approach the game logically, they approach it intuitively. And they are not weaker players for it.

So, I consider myself a (mostly) intuitive player, so let me see if I can present the way I solve this problem as an example:

My first thought when looking at this problem is that this must be a dead shape problem. A few shapes jump to mind:

Click Here To Show Diagram Code: [go]$$W $$ +------------------ $$ | . W X X X . . . . $$ | . . W X O . O . . $$ | . W . X O . . . . $$ | X X X X O . . . . $$ | . O O O O . . . . $$ | . . . . . . . . . $$ | . O . . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . .[/go]

Click Here To Show Diagram Code: [go]$$W $$ +------------------ $$ | . W X O . . . . . $$ | W W . X O . O . . $$ | . W . X O . . . . $$ | X X X X O . . . . $$ | . O O O O . . . . $$ | . . . . . . . . . $$ | . O . . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . .[/go]

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

So then I implement the logical side, how do I get to these positions?

Click Here To Show Diagram Code: [go]$$W $$ +------------------ $$ | . b X O . . . . . $$ | . . a X O . O . . $$ | . O . X O . . . . $$ | X X X X O . . . . $$ | . O O O O . . . . $$ | . . . . . . . . . $$ | . O . . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . .[/go]

The marked points are sente, probably one of those, lets start with "a"

Click Here To Show Diagram Code: [go]$$W White to play and kill. $$ +------------------ $$ | . 2 X O 4 . . . . $$ | 5 3 1 X O . O . . $$ | . W . X O . . . . $$ | X X X X O . . . . $$ | . O O O O . . . . $$ | . . . . . . . . . $$ | . O . . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . .[/go]

uh-oh, that's a seki

lets try the other one

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

now "a" is interesting for black, keeps me from making that second shape I showed above, so what happens if he takes it?

Click Here To Show Diagram Code: [go]$$B $$ +------------------ $$ | . O X O . . . . . $$ | 1 O X X O . O . . $$ | 2 O a X O . . . . $$ | X X X X O . . . . $$ | . O O O O . . . . $$ | . . . . . . . . . $$ | . O . . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . .[/go]

and now "a" has a shortage of liberties

But wait, need to check one more, what if black doesn't connect to my atari?

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

this also leads to the second shape. Nakade, black is dead

So my approach IS logical, but only after my intuition suggests important patterns. All of my sequences try to use or approach these "lighthouses"

Posted: **Thu Oct 11, 2012 7:42 pm**

I gave up on Herman's problem in about two minutes. I was trying to do it systematically, but I'm quite bad about keeping the organization in my head.

Posted: **Thu Oct 11, 2012 11:31 pm**

Around 3 minutes for the first one (had to resort to a process of elimination), 2 minutes for the second (considered shapenaji's a first, then b. b just looked interesting.). Fun.

Posted: **Thu Oct 11, 2012 11:38 pm**

Logical or principle based thinking if applied incorrectly or inadequately can also prevent one from finding a solution. When I first saw this problem, I failed to solve it (I looked at the solution, thinking there must have been some mistake) because my mind locked in on the principle that a straight four is alive.

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

Posted: **Fri Oct 12, 2012 3:41 am**

Interesting problem. I wonder where that starts to become intuitive

Posted: **Fri Oct 12, 2012 5:44 am**

Why is

better than "a"? As far as I can see the both kill and leave white one ko threat for life.

Posted: **Fri Oct 12, 2012 6:14 am**

Splatted wrote:Why is better than "a"? As far as I can see the both kill and leave white one ko threat for life.

Posted: **Fri Oct 12, 2012 6:38 am**

I feel kind of stupid for not seeing that. Orz Thanks for the explanation. :salute:

Posted: **Fri Oct 12, 2012 6:45 am**

It's not quite so simple as killing with the placement means that if you ignore the threat and white lives then she has 1 more point of territory and better yose on the top edge. Also it gives white a sente move on the 2nd line outside to connect up on the 1st line. It is hard to say which of these or the extra ko threat is more important (whether the outside sente move is relevant will depend on the whole board position) but I would probably kill with the throw in.

Life In 19x19

Logical players, intuitive players ..

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