Questions tagged [retrograde-analysis]
Retrograde analysis is the method of deducing information by working backwards from a given position or outcome. This information can be about past positions of the same game, or may contain forward content, such as optimal play.
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How is this retrograde analysis position legal?
On his page on Harry Goldsteen's "Horse Concoction,", Tim Krabbé gives this position by "N. Höeg, 1935."
[FEN "4k3/1p4pp/p1pQ1p2/1q1pp3/8/8/1K6/8 b - - 0 1"]
[...
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Retrograde analysis problem
Given that this position is legal, and could be reached in a legal game of chess, what were the two last half-movess, or one move for White and one for Black?
[FEN "5K2/8/6Pk/8/5Q1R/8/8/8 w - - 0 ...
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Help needed with a problem
On an empty board, how can you place a White king, two White, rooks, and a Black king so that White can give mate in 4 ways from that position?
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From Mate-in-3 to Mate-in-1
Here is my new problem in 3 steps - the key designates here the piece that moves first in the solution. An other way to reach a mate in one I hope you'll enjoy...
[Title "From Mate in 3 to ...
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Prove that White is not allowed to castle here
A friend recently gave me the following weird chess problem to solve. I'm afraid that I'm struggling to see the key idea that would ultimately count as proof. From the position, intuitively speaking, ...
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Problem: Find White's second-to-last move
For the following position to occur in legal play, with Black on move, what would White's second-to-last move need to have been? Note that Black is checked by two pieces on the h1-h8 file and two ...
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Prove the pawn's color and the knight's position
I was recently given a retrograde analysis problem to solve. Even though I've managed to at least intuitively get close to an answer, I don't know how to put it in the form of an acceptable proof. For ...
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"Knight rebus"-Decipher an encoded chess position
Here is a knight rebus. Each letter represents a different type of piece.
Uppercase letters are one color and lowercase letters are the other.
Determine the position. If possible, also determine the ...
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Which chess position requires the most moves to reach?
For each legal chess position there exist a shortest sequence of moves from the starting position to that position.
Which position requires the most moves to reach?
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Can we say for sure that Black's king has not moved?
The following position appears as the 7th puzzle of Raymond Smullyan's Arabian Knights, a book about retrograde analysis.
[FEN "3qk2r/p2pp1bp/bpp2n2/8/3N3Q/1PN1P1P1/P1PPP2P/3K1n2 w - - 0 50"]...
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Least number of moves to achieve a complete switchover of nonpawns in starting setup
[fen "RNBQKBNR/8/8/pppppppp/PPPPPPPP/8/8/rnbqkbnr w - - 0 1"]
During a comp, my friend an I had a team kill and we decided to make this position(legally) before drawing. Then we continued to find ...
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Searching for a "where is the black king" problem
Sometime ago, a friend showed me a position where he had the Black king removed. The goal was to find where is the Black king using some pretty weird reasoning.
There were only a few pieces on the ...
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A problem rebus-reproduce the game
Here is a chess "rebus" problem. In this position, white and black circles correspond to White and Black pieces respectively. Each letter corresponds to exactly one piece type (king, queen, ...
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Can white win in this almost 20 year old puzzle?
It's White to move-can they force a win?. The left bottom is a1 as usual.
[FEN "4k2r/6p1/p4pKb/p2N3p/p7/p5Q1/p1n5/qrn5 w - - 9 9"]
Note for people who saw an earlier version: the position ...
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What was Black's last move?
It's White to move. What was Black's last move, and what could have happened before that?
[FEN "8/8/8/8/8/3P2P1/3P2Pk/2KR3N w - - 0 1"]
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