Shape Problem 6 / Discussion

White to make shape (i)  

Charles So I see this ladder ...

White to make shape (ii)  

... and if the ladder (actually, either one of parallel ladders) is good for White, White might have no problems here. The net might be a strange ko.^[1]

White to make shape (iii)  

Backtrack to here, which is the first chance for White to vary.

White to make shape (iv)  

looks good because the capture now for Black causes shortage of liberties. But if Black answers by extending from , it's a serious ko.

Attempt  

unkx80: Takes some reading to see this. is neccessary to prevent a. After this, White can play elsewhere.

Charles Yes, I thought of just after I went out shopping.

HolIgor: When I set this problem I has this solution in mind. The discussion that followed was interesting, so I will wait for the final words before making the solution page.

Bill: I think that on an empty board (except for the ladder breaker) I would like this variation, keeping sente. I also think that the choice among this variation, the first net variation, and the second net variation depends upon the rest of the board.

What White had in mind  

After clearing up the captured stones

Shortage of liberties  

Black cannot connect because of the shortage of liberties and has to play . White capture and black takes firm grip of two white stones.

The result  

The final white's shape is excellent. It is thick, the eyes are almost there and white kept sente.

What white had in mind  

Black extended with and after captured with . White had to play elsewhere and black filled the ko producing the following position

The result in the actual game  

This was not too bad for White either because there is a great piece of advice that ugly shapes have to be sacrificed; and the shape of the stones is ugly.

Another net  

Bill: As long as we're willing to sacrifice the ugly stones, this doesn't look so bad.

Charles Indeed. But gote.