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 would I detect dead position in a tablebase?
I am programming a tablebase for fairy chess, and would like to conclude the game if mate cannot be reached in any way. I guess this has to be detected when the evaluation (win in... / loss in... / ...
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Do any unique proof games feature an en-passant capture?
Most positions that could be reached, in a specified number of moves, after an en passant capture could be reached just as well without one, suggesting that such positions could not occur in unique ...
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When can you tell which pieces are 'White' from a position where the pieces are colored red and green and you know whose move it is? [duplicate]
Suppose you come across a chessboard where the pieces are colored red and green and there are no labels on the squares. You don't know which move number it is.
What are the positions where, by only ...
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Legal positions with one color to move only?
Most positions in chess can be reached with both black or white to move.
Some positions are only legal with one color to move. One such position is the starting position, which famously can't be ...
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Retrograde analysis of a position in "The Flanders Panel"
Has anybody tried to verify the retrograde analysis of a game from the book "The Flanders Panel" by Pérez-Reverte? So far, I have found only a board reconstruction in a post on The ...
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Term to distinguish between two categories of illegal positions
Consider these two categories of illegal positions. First, e.g.:
Not having exactly one King of each color
Both Kings being in check
Pawns on the first or eighth ranks
Second, e.g.:
Having more ...
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How many more squares can you attack?
(Inspired by this cool problem)
Let’s say it’s White to move. Let A = the number of squares currently attacked by White, and B = the number of squares attacked by White after White’s next move.
What ...
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A mysterious mate in one
Here's a question that's a little off the usual format, but problem questions like this have been done before and are on topic, so here we go!
Question: Can you find the mysterious mate in one? The ...
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Given a legal chess position, is there an algorithm that generates a series of moves that lead to it?
Given a FEN board position, is there an algorithm that can return a PGN move list that evaluates to it from the standard initial position?
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Where are the non captured Black pieces?
[FEN "8/8/8/8/8/PP4PP/2PPPP2/NNBQKBRR w - - 0 1"]
Here is a problem from my blog once more. This is the position after White's 14th move. Seven Black pieces were captured during the game ...
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Which piece was captured last - knowing that this position was reached in the minimum number of moves possible?
This is a puzzle that I made a while ago, but never really published anywhere before (although I posted it on an obscure Dutch telegram channel).
The question is simple: what was the piece that was ...
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Harry Potter Chess Analysis
So, I've been reading Harry Potter and The Philosopher's Stone. If you haven't read the book yet, or watched the movie, and you don't want any spoilers, stop reading this question. Continuing, there ...
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Is the position in this trick question reachable?
I found this trick question on r/Anarchy chess: White to move, mate in two.
[FEN "2R2RK/6PP/5P/3PN/P/1pQ3p/n1p1qbp/5brk w - - 0 1"]
[StartFlipped "1"]
The trick is that
But is ...
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Which methods can be used to prove that a position is illegal?
Given a board position, there are programs that try to find a series of legal moves that lead to it.
Are there algorithms that can do the opposite - prove that the position is not reachable by a ...
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Another problem - Find color of the pieces
Please help me to find the solution of this next problem by the legendary composer Andrej Kornilow. It appeared in Shakhmatnaya Kompozitsiya 41 issue in 2001 and it was dedicated to A. Lobusow on his ...
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