This is a problem from an Android Tsumego app...

Click Here To Show Diagram Code

[go]$$Bc Black to play
$$ ------------+
$$ . . X . O . |
$$ . X O O O . |
$$ . X . . . . |
$$ . . X O O . |
$$ . X . O . . |
$$ . . X X X X |
$$ . . . . . . |[/go]

My solution started like this...



But the app responded like this, saying I was wrong...



But I think that this should now happen...



Where have I gone wrong?

Aside: Why is there no "Problems" subforum and what is up with "Beginners" and "Amateurs" - after a slight holiday from L19, these things do strike you when you return.

You are right !

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The really most difficult Go problem ever: https://igohatsuyoron120.de/index.htm
Igo Hatsuyōron #120 (really solved by KataGo)

Agree, your solution seems valid. I lazily read as solution a placement at T17, but why do it so complicated ?

_________________
Geek of all trades, master of none: the motto for my blog mostlymaths.net

I thought so.

I always prefer to play on the outside of a group like this, even if a placement or throw-in does work.

EDIT: I can't seem to find a problem-feedback option in the app. Does the dev. read L19?

It might be preferable to play 3 @ R17.

Playing from the outside is always better than doing so from the inside, if both options do the job.

_________________
The really most difficult Go problem ever: https://igohatsuyoron120.de/index.htm
Igo Hatsuyōron #120 (really solved by KataGo)

Agree, the placement was my first try, then I read the proposed solution. I'm usually guilty of finding a solution (or a wat to proceed) and sticking to it without looking further. An area I try to improve

_________________
Geek of all trades, master of none: the motto for my blog mostlymaths.net

Where did you go wrong? Hmmm. Maybe buying that app?

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

Perhaps it's "Black to let white live with points."

It's a free app.

Based on this discussion, I won't buy any problem sets once I have finished the free ones.

You probably had the same (overly) trained reflex to that potential eyeshape that I have, I saw T17 instantly. The difference was probably that Charlie focused on a different critical point in that shape. The solutions seem equivalent to me really, White can take sente and leave a ko threat for themselves behind in either case.

What did the app give as the correct solution? There is no lack of amateur tsumego problems with more than one solution.

_________________
Dave Sigaty
"Short-lived are both the praiser and the praised, and rememberer and the remembered..."
- Marcus Aurelius; Meditations, VIII 21

The app provides this solution:

Click Here To Show Diagram Code

[go]$$Bc Tsumego Easy #17
$$ ------------+
$$ . . X . O . |
$$ . X O O O 5 |
$$ . X 1 2 . 3 |
$$ . . X O O 4 |
$$ . X . O . . |
$$ . . X X X X |
$$ . . . . . . |[/go]

This would be why I prefer apps that play out White's moves here, rather than just marking something as incorrect just because your move for White isn't the programs. Of course, apps with more than one variation for White in response to the same starting move are better, just to make sure you actually read things out.

Edit: I mean, if Charlie was presented with then above by the program he'd have no problem finding and and he wouldn't be finding the problem marked wrong for him. He might disagree with but that's where you just confirm again that your also doesn't change the result. In this case there's only ever one eye in there after regardless of what white does so it's much of a muchness. In sdk/strong ddk problems there's often alternative answers but usually the book answer is better in terms of endgame, sente or ko threats or whatever.