Puzzles here...

@i-bex said in #19:
> I don't get you. Your English is making this hard. I still don't understand what's wrong. You made a mistake, failed the puzzle and lost rating.
If so, Thank you for reminding me I failed but why exactly? not that auto chess mate as you said but what?

@bendmotorindex said in #20:
> sorry for my bad English, it is not my native language
Neither is mine so I understand it can be difficult, nevertheless I have trouble understanding what you mean so maybe someone else can help. You can also try translating trough google translate, maybe it will be clearer.

Ambigiusity, I encountered this in many courses like from the 5 answers 3 are right but only 1 is best and qualifies. And it if you want a win then you have to do the same path as that game. maybe a spoiler?
That game is there to see. Look at it 1st and note. That for me is no puzzle then the ones to respond here are better. As Captcha ones not your responses.

@bendmotorindex said in #23:
> Ambigiusity, I encountered this in many courses like from the 5 answers 3 are right but only 1 is best and qualifies.

In this case there is only 1 answer because everything else results in black promoting a pawn with checkmate.

@i-bex said in #24:
> In this case there is only 1 answer because everything else results in black promoting a pawn with checkmate.

You have got the solution and answer and thanks, you are right. That is the 1 of the 3 that is best.