Back on track

Amelia · Post by **Amelia** » Wed Mar 11, 2015 3:56 pm

Ed, thank you. I will add those shapes to my study plan.

Kiai

Without a doubt something I'm missing at the moment :-?

Well, next game I better show some fighting spirit!
Also, no more saving useless stones :mrgreen:

And finally, tsumego. Lately I reopened GGPB vol. 3 and was ashamed of my poor results. Poor reading does not help :study:

Amelia · Post by **Amelia** » Fri Mar 13, 2015 4:43 pm

Amelia wrote:Well, next game I better show some fighting spirit!

I did! It was an offline game, so I don't have a record to show off. But I managed to conclude this pretty bad week by a very agreable game against a 7k where I managed to fight back and take control. I was ahead, and I was fairly confident I'd win, but by the time I started filling dame, I overlooked a shortage of liberties that cost me the game.

Despite that pretty bad mistake, it's the best game I've played in a while :rambo:

And I now know some very nice people to play with on Fridays

Aside from that, I decided to take lessons with Kaz. He emphasizes basics, and seems to be very involved in his student's progress, which is why I picked him. I think of taking about a lesson per week, or one every two weeks when I lack time. Kaz looks at his student's games, picks their worst bad habits, and helps them to work on it by giving many problems directly related to that. I hope this way I can build a stronger foundation to my game, and have more focus to my studies.

Additionally, I'm going through GGPB vol 2. Again. But differently :-)

Earlier I would skim through that book and feel happy to have a rather high solving rate (most problems are easy for me now, they are related to shapes and vital points I know). Now I set the position on the board. I try to challenge the correct answer. I try to understand it thoroughly, as opposed to my previous superficial understanding. Today was my fisrt try with this new approach, and it's more interesting than I would have thought.

Amelia · Post by **Amelia** » Fri Mar 13, 2015 5:06 pm

For example this position. This is a problem I often got wrong earlier on first impulse. Then I'd look at the answer, learn it - and after some time, forget it again.

Black to answer White 1.

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

My first impulse was always to play on the second line to block.

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

But trying that one on the board, I noticed white has this. And I just thought: aaargh, broken shape! No way this is the correct answer...

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

So how about that?

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

I thought that was a fairly good result and was lazy enough to then look at the answer. Well, it turns out there is a better move:

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

But this one feels wrong! Because white can do this:

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

This is bad. I must be missing something. I couldn't find a way to prevent white from connecting with either black a or b. :scratch:

I'll look at it again after I've slept a bit.

Edit: corrected mistake in diagrams

topazg · Post by **topazg** » Sat Mar 14, 2015 4:11 am

I'm not actually sure there is a right answer. There's a whole board out there (and, in this case, with that star point where it is, it looks like a really big board out there).

Does black have a stone just off screen on the right?
What's happing on the right edge of the board?
How about the centre of the board?

All these questions can affect what's locally right in a position like this. In some cases tenuki is fine too, treating Black's stone as kikashi if it forces a low sliding response.

Locally, you can't cut, but connecting on the first line with a bit of added second line crawl is a bit cringing for White. It's normally better to push for endgame rather than create that peeped one point jump just because Black gets to abuse the lack of liberties

Edit: some pretty pictures

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

Why would you play :b4:

? "a" is more locally reasonable, and tenuki should always be an option depending on the rest of the board.

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

This is tesuji to stop White continuing his march

tentano · Post by **tentano** » Sat Mar 14, 2015 4:41 am

Amelia wrote:Now I set the position on the board. I try to challenge the correct answer. I try to understand it thoroughly, as opposed to my previous superficial understanding. Today was my fisrt try with this new approach, and it's more interesting than I would have thought.

It'll do your fighting skills a whole world of good to keep doing this. If you can confidently know why your answer is correct, you'll have an easier time doing it right in a game. Even better, you will not have any doubt about mistakes your opponents make.

Click Here To Show Diagram Code: [go]$$W $$ | . . . , . . . . . , . . . $$ | . . . . . . . . . . . . . $$ | . . . O . . . . . . . . . $$ | . . . . . . . . . . . . . $$ | . . O . O . . . . . . . . $$ | . . . . . . . . . . . . . $$ | . . X X . X . . X , . . . $$ | . . . . . . . 2 . b O . . $$ | . . . . . . 3 a 1 4 c . . $$ | . . . . . . . . . . . . . $$ +--------------------------[/go]

This is what happens if white tries to push in like in your last diagram.

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

is threatening to capture :w1:

. A response at a) results in white being cut in two. This is awful for white, since not only are the three stones stranded inside (and maybe dead soon) but black has a solid wall against the now very lonely outside stone.

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

Responding at b) causes a more sedate result, which is still worse for white than in the solution.

Click Here To Show Diagram Code: [go]$$W $$ | . . . , . . . . . , . . . $$ | . . . . . . . . . . . . . $$ | . . . O . . . . . . . . . $$ | . . . . . . . . . . . . . $$ | . . O . O . . . . . . . . $$ | . . . . . . . . . . . . . $$ | . . X X . X . . X , 0 . . $$ | . . . . . . . 2 . 8 O . . $$ | . . . . . . 3 6 1 4 5 . . $$ | . . . . . . . 7 . 9 . . . $$ +--------------------------[/go]

Maintaining the connection at all cost with c) is not good for white either. It's probably worse than giving up :w3:

.

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

The point here is those three marked stones forming a neatly connected set. That's the shape they want you to become familiar with. You have to see that :b4:

for this to make much sense, though. But that's GGPfB for you. The not-really-tsumego parts can feel like articles of faith.

@topazg:

I've always considered that if the rest isn't shown, then the problem doesn't intend for me to consider it either. There's usually one especially obvious answer that the author is trying to demonstrate. It's like how some endgame problems have a choice between a ko for more points than a simple sente endgame. They probably don't mean the more complicated answer, even though sometimes it's valid.

If you worry too much about the hypothetical rest of the board, you're just being pointlessly difficult. Any tsumego could be correctly answered by tenuki if there's a bigger point on the rest of the board. Maybe you should resign because the rest of the board is lost?

Boidhre · Post by **Boidhre** » Sat Mar 14, 2015 6:08 am

tentano:

topazg · Post by **topazg** » Sat Mar 14, 2015 6:42 am

Yes boidhre, or more commonly:

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

Which could continue:

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

Hence the justification for playing :b6:

first, as it's nominally sente, and protects the "important" area in the lower left.

@Tentano: You are welcome to have that opinion of course, but I'm really not making it pointlessly difficult. This isn't a tsumego problem - it may not even be a book problem, but learning "this is always the right answer" is IMO a bad habit to pick up, when the reality can be that there is more than one right answer depending on context. It's quite possible Amelia's first instinct is indeed better for the board. It's played in some contexts professionally, so if the given "correct" answer stopped her from considering it, then I think a teaching/lesson mistake has been made.

Go is difficult, and I generally feel it's more generally more useful to ask yourself "why am I doing this? Does it really help me overall more than an alternative?" than to learn single responses as "right in all situations"

PS As an addendum:

Click Here To Show Diagram Code: [go]$$W $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O . O . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X X . X . . X , . X . . . , . . . | $$ | . . . . . . . . . . 2 . . O . . . . . | $$ | . . . . . . . . . . 4 1 . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]

Black does get a reasonable big follow up with the given answer. There's not a similar value one in Amelia's original instinct that protects, is worth nominal points and has a decent followup

tentano · Post by **tentano** » Sat Mar 14, 2015 6:46 am

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

Here's a little twist on the endgame problem I had in mind in my last comment. HINT: it's not a ko!

It just showed up in a game, as if it knew I wanted to show it.

I probably don't disagree that much with you, topazg, because if I had never memorized the potential ko I would not have answered the above correctly.

Bill Spight · Post by **Bill Spight** » Sat Mar 14, 2015 6:53 am

topazg wrote:I'm not actually sure there is a right answer. There's a whole board out there (and, in this case, with that star point where it is, it looks like a really big board out there).

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

There is something fishy about this problem, it seems to me, and now I think that the star point is a clue as to why. There is no star point on the 13-4 point on a real board, and there is a star point on the 10-4. So I think that there is a mistake in the problem diagram.

Click Here To Show Diagram Code: [go]$$W Actual problem? $$ | . . . . . . . . . . . . . $$ | . . . O . . . . . . . . . $$ | . . . . . . . . . . . . . $$ | . . O . O . . . . . . . . $$ | . . . . . . . . . . . . . $$ | . . X X . X . . X , . . . $$ | . . . . . . . . . . O . . $$ | . . . . . . . . 1 . . . . $$ | . . . . . . . . . . . . . $$ ---------------------------[/go]

This problem makes more sense.

That double two space extension was weird, and because the double extension was so thin, :w1:

was questionable, as was the answer given. And in this diagram the star point is correct.

topazg · Post by **topazg** » Sat Mar 14, 2015 6:54 am

@Bill, yes, the star point had been bugging me too!

tentano · Post by **tentano** » Sat Mar 14, 2015 7:03 am

@topazg:

topazg · Post by **topazg** » Sat Mar 14, 2015 7:06 am

@tentano:

what ko am I missing?

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

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

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

Click Here To Show Diagram Code: [go]$$B $$ +-------------------------- $$ | . . . . . 1 . 3 8 . . . . $$ | . . . . . O X 2 4 5 . . . $$ | . . . O . O O . 7 C X . . $$ | . . . O . . . O O X . . . $$ | . . . . . . O . X . X . . $$ | . . . . . . O O O X X . . $$ | . . . . . . . . . . . . .[/go]

tentano · Post by **tentano** » Sat Mar 14, 2015 7:25 am

@topaszg:

Bill Spight · Post by **Bill Spight** » Sat Mar 14, 2015 7:25 am

topazg wrote:Does black have a stone just off screen on the right?
What's happing on the right edge of the board?
How about the centre of the board?

All these questions can affect what's locally right in a position like this. In some cases tenuki is fine too, treating Black's stone as kikashi if it forces a low sliding response.

tentano wrote:I've always considered that if the rest isn't shown, then the problem doesn't intend for me to consider it either. There's usually one especially obvious answer that the author is trying to demonstrate. It's like how some endgame problems have a choice between a ko for more points than a simple sente endgame. They probably don't mean the more complicated answer, even though sometimes it's valid.

If you worry too much about the hypothetical rest of the board, you're just being pointlessly difficult. Any tsumego could be correctly answered by tenuki if there's a bigger point on the rest of the board. Maybe you should resign because the rest of the board is lost?

There is a general principle of discourse that applies both within and across cultures, that if you do not mention something you do not think that it is relevant -- unless it is something that "everybody knows". So if a part of the board is not shown, it is not relevant, as tentano says. It seems to me that that principle is followed in modern tsumego, but not in ancient tsumego nor in yose problems.

In ancient tsumego it seems to me that the rest of the board is assumed to be empty. The point is not to make the biggest play on the board, but to achieve a goal, such as connecting or killing stones. If stones escape to the rest of the board, they are usually safe, but not always, and sometimes whether the escaped stones live or die is an important part of solving ancient tsumego.

In yose problems the threat to escape to the rest of the board is treated as sente. There are a couple of problems with that. First, the rest of the board is not treated as irrelevant, but as belonging to one player, or a part of it is treated as belonging to that player, in violation of the general principle mentioned above. Second, for the escape to be a big enough threat to be sente is often unrealistic. Third, treating the threat to escape as sente means treating some plays as double sente, which is problematic.

topazg · Post by **topazg** » Sat Mar 14, 2015 7:42 am

Thanks Bill, interesting post, and I agree, it's a complicated point. I think I was swayed by the comments on the original post about the position rather implying that "I thought this was ok, now I know it's not, but why not?" and it was making my learning spidey-senses tingle a bit.

"Black to play" is always going to be ambiguous I guess unless it's life and death. Even "Black to connect" is ambiguous as there are plenty of ugly and clunky ways of connecting those stones. Hard to phrase a problem like that really, or IMO make it all that meaningful. I'd rather see it as a discussion with a number of answers and some possible purposes of each explained.

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