"Trick" Mate in 1 puzzle

For those who have seen this I think it would be best to let others try and solve this puzzle first:D

 Hint: The title is a clue

The 'Hint' isn't much of a hint !

If there's a mate in 1 move, my name's Kasparov !

The fastest one I can find is:    1. b8=Q+ Kxb8 2. Qd8#

Which, coincidentally has the outline shape of the letter "1",  so is that what is meant by the title ?

Yeah, knew it when I saw it because I've heard of the idea, but it's illegal.

Why not Kxb8?

If you're breaking one rule, why not another?

"If you're breaking one rule, why not another?"

Exactly this. Thank you.

Promote the pawn to a black knight ??

Yeh, great joke - is anyone in the room laughing ?

Exactly what I mean. Lol

the b8 = black N is correct.

for those who don't know, when the promotion rule was introduced, there was no specification about colour of the promoted pawn, because no-one would have any reason to promote to the opposite colour.

this puzzle was created by a GM to show why "promotion only to the same colour" needed to be made an official rule (hence this is now illegal to checkmate this way)

Would have been a good puzzle a while ago then.

The "Trick" may be that the board is flipped -- the white pieces must be moving down.

And people wonder why I gripe about illegal positions. :)

IF pawn gets converted to black knight, its conversion not promotion! no such rule of conversion.

interesting