Hi everyone.

This is one of the problems I've been going through recently.

Would you be so kind to explain to me why one particular variant is marked as 'wrong'?

Thanks.

I'm confused. What is the problem's task? Black to play and lose? Both variations white achieves that.

2nd variation is correct, White saves a ko threat. If your source says otherwise, it's made a mistake.

Also very confused about why black plays first...

I should have presented it slightly differently. E18 was marked, as if it were where Black had just played. Corrected.

I'm still confused. Doesn't black E19 also work in response to E18?

This is another solution to the problem which, I'd think, has little in common with the original question.

Generally questions with more than one solution for first move are considered bad. In other words, the answer to both my question and yours is the same - I just wasn't sure if the question was indeed that terrible :p