Chemistry and life

Chemistry and life  

I don't remember the whole board position, but at some point I became very much afraid that I would not be able to build the second eye in the center. Lack of confidence is one of the factors that makes us panic when playing against stronger players. We agree to give in a little bit just to be alive. And then we give in somewhere else and finally the game is lost.

Returning to this position. I knew that I had a tesuji. It is either life or ko. If it is life then it is life in gote, but I was ready to give in here :(.

White has choice: either a, allowing Black to live, or b, White a with a large ko.  

My opponent, smiled, exclaimed: "What is this? Chemistry and life?", played a, I replied b and the game went on.

I have to provide some explanation. The word "chemistry" is quite often used as a substitution to "trickery" in our language, at the same time "Chemistry and life" was the title of a popular science magazine. It was a good joke.

Later, when we analyzed the game, my opponent said that though the tesuji was cool, he did not like it. Why? "Because, you built two eyes for my group, too."

It is great to play with a strong player. A little hint like this gives one a lot to think about. Of course, sometimes I am forced to build eyes for my opponent, but how I hate it!

Why sacrifice a stone?  

Alain: In the given position, there is no need to sacrifice a stone at a.

Playing at immediately is better. If White wants to attack the black group she will have to protect the cutting point at a anyway. This is a good illustration of the principle "Don't play unnecessary moves?".

If White tries to resist  

If White tries to resist, the throw-in tesuji of creates a big ko. (If White connects, the ko becomes bigger after Black plays at a.)

It is not reasonable for White to play since Black has many local ko threats to make two eyes for his group. A more subtle way of playing would be to protect the cut at a.

If White tries harder to resist?  

HolIgor

Black 1 is still better  

Alain : You are right, I overlooked the possibility of White resisting harder in the "If White tries to resist" variation. If White plays at , Black has to play at before throwing in.

Anyway, this doesn't change the conclusion that Black should play before cutting at . Playing like this, you give White the "chance" to play which is an unreasonable move. After Black wins the ko (which is very likely since he has a lot oflocal threats starting with a for instance), will obviously become a bad move.

Locally, the correct answer to would be to protect the cutting point at .

The locally correct sequence  

This seems to be the correct sequence, locally, if Black wants to make two eyes here.

This is at least two points better than cutting immediately at a (comparison with the reasonable sequence when White doesn't play the ko).

AlainWettach

How about this move?  

Taking a purely local standpoint, how about playing at in response to ?

And how about this one?  

In a similar fashion, I don't think Black has a chance to live by making two eyes or a ko in the corner alone.

This sequence is still best for White  

However, from a global perspective, I will still say that this sequence for White is still the best.

--unkx80

This now works  

With there, the tesuji works.

 HolIgor