Place and Mate

Werner Keym

Place the Black King, then mate in 1
2 solutions

Kc6 or Kc8 and 1.Qb5 or 1.Be6#; If the Black king is placed at d3, then 1.0-0-0 would have been a solution if there were a leagl previous move for Black, and since there isn't the king can't be placed there.

Originally posted by ilywrin
Kc6 or Kc8 and 1.Qb5 or 1.Be6#; If the Black king is placed at d3, then 1.0-0-0 would have been a solution if there were a leagl previous move for Black, and since there isn't the king can't be placed there.

bK@c8 doesn't work, because 1.Be6+ is not mate. Black plays 1...Kd8.

bK@c6 followed by 1.Qb5# is one solution.

The 2nd solution remains to be found.

Nothing. I thought I found a last move for black going to d3 but I was wrong.

After checking all possible black squares for a mate in 1, I only found K@d3. Then I tried to find how this position can be achieved and wasn't successful for 10-15 mins. But then bingo:
K@d3 is indeed correct. It's blacks turn and he checkmates on g1 right?
The position can easily be achieved retrowise. For example: 1. Qd6-h2 Bg5-f4 2. Qg1#

Originally posted by crazyblue
After checking all possible black squares for a mate in 1, I only found K@d3. Then I tried to find how this position can be achieved and wasn't successful for 10-15 mins. But then bingo:
K@d3 is indeed correct. It's blacks turn and he checkmates on g1 right?
The position can easily be achieved retrowise. For example: 1. Qd6-h2 Bg5-f4 2. Qg1#

Right! With bK @ d3, it must be Black's turn to move, and mate in 1 by 1...Qg1# follows.

Originally posted by BigDoggProblem
Right! With bK @ d3, it must be Black's turn to move, and mate in 1 by 1...Qg1# follows.

What I didn't expect that part of the individual solution could be who's turn to move it is, with both solutions requiring a different side on the move (k@c6 isn't mate in 1 with black to move). Is this common?

Originally posted by Mephisto2
What I didn't expect that part of the individual solution could be who's turn to move it is, with both solutions requiring a different side on the move (k@c6 isn't mate in 1 with black to move). Is this common?

I guess it's not, it took me a while also. But on the other hand, what are instructions for? Here it wasn't stated anywhere, who's turn it is.

Originally posted by Mephisto2
What I didn't expect that part of the individual solution could be who's turn to move it is, with both solutions requiring a different side on the move (k@c6 isn't mate in 1 with black to move). Is this common?

It's most common in mate-in-1 problems. Most of those rely on retro analysis (a simple forward mate in 1 is not usually interesting enough on its own).