Life In 19x19

deja wrote:

daniel_the_smith wrote:Right, so white makes a ko threat...

But wherever white moves next, black just takes that group, no?

What if white's next move threatens to capture 40 stones? Do you still just take the lower right group?

Here's a more quantitative way to look at it than just "killing is better than ko":

In your solution, the sequence goes bwbWbW, where uppercase letters are moves played elsewhere on the board.
In the correct solution, the sequence goes bwbW (or bW, if White stops thrashing).

In both cases, both players have played the same number of moves as each other. But in your solution, white has gotten to play an extra stone somewhere else on the board for free (two capital W's instead of one).

dfan wrote:

deja wrote:

daniel_the_smith wrote:Right, so white makes a ko threat...

But wherever white moves next, black just takes that group, no?

What if white's next move threatens to capture 40 stones? Do you still just take the lower right group?

Here's a more quantitative way to look at it than just "killing is better than ko":

In your solution, the sequence goes bwbWbW, where uppercase letters are moves played elsewhere on the board.
In the correct solution, the sequence goes bwbW (or bW, if White stops thrashing).

In both cases, both players have played the same number of moves as each other. But in your solution, white has gotten to play an extra stone somewhere else on the board for free (two capital W's instead of one).

I was looking at the problem from a local position only, since we have no idea what else is on the board. So "wherever white moves next" was in the context of white trying to save the two groups.

When you see and solve this problem the first time, it really is hard to forget it because the solution, while not particularly difficult, is just so cute.

Yeah, I also had a hard time with this problem in "Graded Go Problems For Beginners Volume 3". There were like a handful with this tactic. Pretty astonishing =)

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Similar problem, but from real kgs game. B to kill ^^ (solution wasn't played in game, kibitz found it)

k43r wrote:Similar problem, but from real kgs game. B to kill ^^ (solution wasn't played in game, kibitz found it)

Nice