Puzzle review request


#1

Hi, i’m trying to do some puzzle but sometimes i just doesn’t understand why my moves are judged bad.
Excuse by advance my expression, i’m french and try to speak english as well as i can…

Here the example : i tried to do this, and understood the “right” solution : https://online-go.com/puzzle/7589

And when i play to T17 to capture S17, i got this message :

ok, black has to fight a ko… so i pushed in T19 to capture, and i imagine white will secure and “push back” by the time i capture the stones in “L” : here is the result :

Here is the solution of the problem, why is this position better than the one i propose ? Or perhaps i missed something in the ko fight that i didn’t understand ?

I’m not sure to explain myself very well, so i created a demo of the problem here : https://online-go.com/demo/view/354230


#2

I think it is implicit in the puzzle that the situation is local and white might have ko threats elsewhere on the board. Therefor after you take with T19, white might play a ko threat elsewhere on the board and then after you answer it, White retakes at T18.


#3

in your variation there is a ko black needs to win in order to capture. you assumed white would protect and give up the ko. in an actual game white would look for a ko threat and actually fight the ko. there is no doubt, that this i a very good ko for white. black is the only one who stands to lose something, white can only win.
https://senseis.xmp.net/?HanamiKo

therefore it is better for black to avoid the ko and capture outright.

[EDIT: @Kosh beat me to it]


#4

@Kosh is just relieved to not be wrong. I could see you replying and it was like waiting for the teacher to mark my paper.

Maybe now I can claim to be a ‘Master of Ko’.

NOT Go memes!


#5

lol :smiley:
“Master of Ko” eh? the jury is likely still out on that matter, but you have my vote, for whatever thats worth :thinking:.


#6

Understood ! The problem is that i forgot everytime the problem of the “ko threats” elsewhere on the goban that could annoy me in this situation…


#7

Even if there isn’t any “ko threats” elsewhere on the board, the Ko result decreases the value you gained, because you need extra moves to clean the Ko situation.
So, that why in general, if a “clean kill” result can be reached, it’s always better than a Ko result, especially for a puzzle.