Ko threat: Ladder breaker versus escape

[Milkman]

I believe this is from the Janice Kim Vol II Way of the Moving Horse book.

The example given is:
.

Ignoring the rest of the board state possibilities, in general, is it better to play a simple ladder escape, or a ladder breaker? My thought is that if the threat is not ignored, then you're just wasting stones in a ladder that'll eventually die (once you run out of threats or the ladder becomes huge). And then you're going to just lose those stones. Whereas if you play a ladder breaker somewhere else, it's still a ko threat, and if they don't ignore it, at least you've got a stone that has some potential on the board.

[EdLee]

Ignoring the rest of the board ... in general...

No.

We must look at the specific board. If a ladder break is better, you play it. If running the ladder is better, you run.

[HermanHiddema]

I believe this is from the Janice Kim Vol II Way of the Moving Horse book.

Ignoring the rest of the board state possibilities, in general, is it better to play a simple ladder escape, or a ladder breaker? My thought is that if the threat is not ignored, then you're just wasting stones in a ladder that'll eventually die (once you run out of threats or the ladder becomes huge). And then you're going to just lose those stones. Whereas if you play a ladder breaker somewhere else, it's still a ko threat, and if they don't ignore it, at least you've got a stone that has some potential on the board.

Yes, each stone in the ladder loses points, while the ladder breaker does something useful, but running out of the ladder provides a lot of ko threats, while a ladder breaker provides only one.

So it really depends on the size of the ko and the number of threats you need.

[Boidhre]

In that book, black threatening to escape from the ladder gave black many, many ko threats so black could win the ko above. The issue was on in that position black running out didn't help black and just meant white captured every stone black put down as a ko threat and made white very strong in that local area.


For reference this is the diagram position in the book, I've omitted the diagrams after this one, but essentially black plays four moves threatening to escape the ladder before white gives up the ko and captures resulting in white becoming very thick on the bottom.

$$W
$$ --------------------+
$$ . . . . . . O O X . |
$$ . . . . . . O X . X |
$$ . O . . . . O X X 1 |
$$ , . O O . . O O O . |
$$ . X . X O O . . X O |
$$ . . . X . . X . X . |
$$ . . . . X . . . . . |
$$ . . . . . . . . . . |
$$ . . . . . . . X . . |
$$ , . . . . . , . . . |
$$ . . . . . . . O . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ . . . . . . . O O . |
$$ , . . . . . O . X . |
$$ . . . . O X O X . . |
$$ . . . . . O X X . X |
$$ . . . . . . . . . . |
$$ --------------------+

Click Here To Show Diagram Code

[go]$$W
$$ --------------------+
$$ . . . . . . O O X . |
$$ . . . . . . O X . X |
$$ . O . . . . O X X 1 |
$$ , . O O . . O O O . |
$$ . X . X O O . . X O |
$$ . . . X . . X . X . |
$$ . . . . X . . . . . |
$$ . . . . . . . . . . |
$$ . . . . . . . X . . |
$$ , . . . . . , . . . |
$$ . . . . . . . O . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ . . . . . . . O O . |
$$ , . . . . . O . X . |
$$ . . . . O X O X . . |
$$ . . . . . O X X . X |
$$ . . . . . . . . . . |
$$ --------------------+[/go]

Note: She doesn't recommend a ladder breaker here, just to find a different ko threat than trying to escape from the ladder.

[Dusk Eagle]

The ko in that diagram isn't even that big. White is alive without capturing the corner, and black's outside group is okay as well. Depending on what's on the other half of the board, it might be too early to even fight that ko, and if your opponent tries to then you can just give it up and take any two free moves elsewhere.