It cannot be white to move. Only last move possible for black would have been Kh2-h1. But then it’s impossible for white to have delivered the check (Bishop is stuck in the corner !)
Here’s a further puzzle: Under what conditions would computer chess engines—even the strongest ones—find White’s previous move completely rational to play?
I haven’t tested this particular case, but the general point is a major known problem that’s encountered while configuring engines for game play.
My caption is a hint: “A Nalimov headache in a Nabokov setting.”
didou: White have played : Nb6-a8+ (discovery check). Black responded with Ka7xa8.
The correct solution.
Susan: It took me about 2 seconds to come up with my theory for the last pair of moves.
But of course Susan, you are world champion. Even the 2 seconds is a wee bit long :). Just kidding of course. ——————- For everybody else:
28 years ago I ran into the book, The Chess Mysteries of Sherlock Holmes, by Raymond Smullyan. I found it absolutely fascinating. Chess puzzles, which the computer couldn’t even accept as an input, let alone solve it. With these, you are on your own. The presented one is the easiest, in fact it was the decoration of the book cover at the time. The rest are far, far more difficult.
As it happens, the picture itself is not about the puzzle, that just came to my mind to place on the chessboard when I made the picture.
Surreal thoughts of a chess tragic.
“Hmmm, I must have dozed off. If only I could remember whose move it is.”
I must be dreaming – how did I get here?
It is white’s move but he got up and left. Is he going to return? Did he miss Ba7?
“I just played Kf1… Next move I play : a8Q#… How brilliant I am !”
to anon 7:41
It cannot be white to move.
Only last move possible for black would have been Kh2-h1.
But then it’s impossible for white to have delivered the check (Bishop is stuck in the corner !)
The near side is white’s side.
The Thinker is playing the black pieces. What was black’s last move and what was white’s move before?
The setup on the board is probably the easiest of retrograde chess puzzles of Raymond Smullyan.
Gabor (I made the picture, that’s how I know 🙂
Here’s a further puzzle: Under what conditions would computer chess engines—even the strongest ones—find White’s previous move completely rational to play?
I haven’t tested this particular case, but the general point is a major known problem that’s encountered while configuring engines for game play.
My caption is a hint: “A Nalimov headache in a Nabokov setting.”
I got it !
White have played : Nb6-a8+ (discovery check).
Black responded with Ka7xa8.
So please forget my earlier comment !!
It took me about 2 seconds to come up with my theory for the last pair of moves. But of course it is only my theory 🙂
Best wishes,
Susan Polgar
Gabor wins the art contest!
Great job!
didou:
White have played : Nb6-a8+ (discovery check).
Black responded with Ka7xa8.
The correct solution.
Susan:
It took me about 2 seconds to come up with my theory for the last pair of moves.
But of course Susan, you are world champion. Even the 2 seconds is a wee bit long :). Just kidding of course.
——————-
For everybody else:
28 years ago I ran into the book, The Chess Mysteries of Sherlock Holmes, by Raymond Smullyan. I found it absolutely fascinating.
Chess puzzles, which the computer couldn’t even accept as an input, let alone solve it. With these, you are on your own. The presented one is the easiest, in fact it was the decoration of the book cover at the time. The rest are far, far more difficult.
As it happens, the picture itself is not about the puzzle, that just came to my mind to place on the chessboard when I made the picture.