Mate in 1

??? There are only two possible ways to give check!

That was easy.

 If the puzzle is a mate in one, It's a safe bet it's not going to be Fischer level.

 You can have tricky mates in 1:

Those en passant ones are so stupid (even though they look cool). How do you know they played ...b5 last move?

 That's... kinda the point. You have to work out what their last move was, in order to know that en passant is valid.

not hard i guess problems like the one in reply might be the only tricky kind of 1-movers

A good puzzle.

Nice.

can someone help me? I can't see how the puzzle above is a mate in 1.

wait is it: en passant with the back white pawn so it is mate with two pawns?

They're especially good when it needs to be proven that it's the only possible last move (as is the case with this one).  I really enjoy retrograde analysis puzzles.

so it is en passant?

 You have to look at black's other pieces and see that there is no other move than ... b5 that leads to that position. Here's the diagram again.

So what about the king? Obviously, it can't have been on b6, where the two kings would be adjacent. It may have been sitting on b7, checked by the pawn on a6. But then how did that pawn get there? Both a5 and b5 are occupied, so it can't have just moved or captured to that square.

That leaves black's pawn. Maybe it moved from b6 to b5? Yes, except that it attacks the white king on b6, so with black to move, that was an illegal position.

Therefore, we know that black's only legal move was ... b7-b5, allowing white to play axb6 e.p. #