The nearly minimal problem

fanfan · #1

Hello,

For many (many) years, i ask beginners to solve the following problem, that I call "the nearly minimal problem": on an empty goban, Black plays at the 1-1 point, then White tries to make a living group with a white stone on the 1-1 (the word "with" is important).

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

Easy?

EdLee · #2

Hi fanfan, Does B resist or pass forever when W moves each time ?

fanfan · #3

Of course, Black replies and tries to kill White.

EdLee · #4

fanfan wrote:

Of course, Black replies and tries to kill White.

Thanks for clarifying. The "of course" part was not obvious, since for raw beginners, we sometimes "pass forever" to teach them some things.

If B resists, it's not obvious to me this can be done, nor does this appear to be a problem for raw beginners.

Just to be very clear, when you say beginners, do you mean they know only the most basic rules ? Do they "know" about ladders ? Do they "know" about real eyes and false eyes ? Please clarify.

fanfan · #5

Hello,

I ask beginners to solve this problem just to train them. But you are right : this is a difficult problem.

Here, my aim is to determine who will win the figth since I am not sure myself to be able to solve this problem.

EdLee · #6

fanfan wrote:

I am not sure myself to be able to solve this problem.

Hi fanfan, I feel it's important and fair to warn the "beginners" you don't know if this problem has a solution.

Also, I don't think this is appropriate for raw beginners.

MMaestro · #7

When I was running my club before, I used to have a friend who would teach beginners in a similar way, except he would play on the 2-1 point, not the 1-1. I think for the 1-1 point, white can simply play the 2-2 point and keep extending each time black pushes. But for the 2-1 point, the shoulderhit is more difficult because black's pushes actually gain eyespace

Bill Spight · #8

fanfan wrote:

Hello,

For many (many) years, i ask beginners to solve the following problem, that I call "the nearly minimal problem": on an empty goban, Black plays at the 1-1 point, then White tries to make a living group with a white stone on the 1-1 (the word "with" is important).

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

Why?

fanfan · #9

MMaestro wrote:

... for the 1-1 point, white can simply play the 2-2 point and keep extending each time black pushes...

If White plays on the 2-2 point, Black plays at the 3-3 point, and it is not obvious that White can take the 1-1 and play at the 1-1 later without dying. For instance:

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

fanfan · **#10**

Bill Spight wrote:

Why?

This is just a problem that could be of some interest.

Uberdude · **#11**

I could just about understand you posing that problem to teach Batoo, the Korean baduk variant that adds Starcraft-style visuals and bonus points for occupying certain squares, but what's the point for Go? Do you find it engages and encourages beginners, teaching them useful Go skills? Because I'm a 4d so pretty good at Go compared to a beginner but after my initial "WTF?!" struggle with that problem.

I think this is a better minimal problem for beginners:

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

fanfan · **#12**

Uberdude wrote:

Do you find it engages and encourages beginners...

Forget the word "Beginners". I used the term just to introduce the problem. I agree that it is not the first thing to show to a beginner.

PeterN · **#13**

My first instinct on looking at this was to laugh and think it was easy... then I thought about it a bit more and went :scratch:

.

I'm suspecting this may be a situation where the only winning move is not to play :lol:

(or tenuki at least).

And yes I know that completely avoids the question.

PeterN

Charlie · **#14**

Er... I still don't get it. For instance, the problem doesn't say that you have to capture the black stone, only make a living group that happens to have a stone at 1-1. I'm fairly certain white can make life after this :w6:

...

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

oca · **#15**

that's a fail so far for me :blackeye:

fanfan · **#16**

Charlie wrote:

Er... I still don't get it. For instance, the problem doesn't say that you have to capture the black stone, only make a living group that happens to have a stone at 1-1...

How do you expect to put a white stone on the 1-1 without capturing the black stone which is already on the 1-1?

fanfan · **#17**

@Charlie

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

@oca

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

MMaestro · **#18**

@fanfan:

For that position you end up with, I recommend looking at gengen gokyo

http://eidogo.com/#4rmBZ5MFq

fanfan · **#19**

Hello,

Don't forget that White has to fill the 1-1 point with a white stone to claim victory. That means that if White just try to live on the edge, he has to make 3 eyes (the one at the 1-1 point that he will fill, and two other eyes to live)!

MMaestro · **#20**

Ah I didn't catch that. In that case though, the 3-3 point seems fine:

http://eidogo.com/#Coif89KX

The nearly minimal problem

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