Questions tagged [problems]
Chess problems consist of a board position and a task. Most ask for a line of play that mates black in a set amount of moves, or a combination that results in a winning position. Many other types exist, including, but not limited to, construction tasks for various positions and proof games that have numerous goals, selfmates, helpmates, and retrograde analysis. Tournaments and championships exist for composing of original problems and for speed-solving.
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Engine to solve direct mates on larger boards?
Does anyone know of a problem engine that will solve direct mates on larger boards (e.g. 10x10, 12x12 etc), please?
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Chess problem content in Ludwig TV Show?
My UK-based brother informs me that a recent popular TV series called Ludwig contains some chess. According to one review there is a scene of "reverse chess (where maths, probability and reason ...
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Is it possible to create a board position where White must make the move that leads to stalemating Black to avoid Black stalemating White?
It's pretty common to see positions where White has to checkmate Black to stop Black from checkmating White. I was wondering about the same concept with stalemate.
At first, I thought it was ...
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Can a series of legal moves end in this position?
With white having all pawns promoted to queens, and all pieces in their original positions, and black only having their king left, checkmated?
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Threefold repetition: what's the minimum number of pieces and/or material points required?
I found the following position online where White's best course is to force a threefold repetition with the sequence Qg5-Kh8-Qf6-Kg8 because all other moves lose:
[Title ""]
[FEN "q4rk1/...
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What is the greatest number of moves a game can be from a checkmate?
I should specify that I'm not asking about the longest forced checkmate (or forced checkmates in general); I am aware that the longest known forced mate is(was?) about 600 moves long, and this is not ...
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What's the answer to this castling rights problem?
[Title "#2 - Leonid M. Borodatow. Die Schwalbe 163 02/1997"]
[FEN "r3k3/2pN3P/5PPP/6pp/7p/6P1/N5P1/R3KB2 w - - 0 1"]
Different sources give different answers.
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Long proof game with rooks
I am trying to track a very special proof game I saw many years ago when I learned about proof games (a board position is given, and the challenge is to find the unique sequence of moves from the ...
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Zugzwang where the side to move must be mated in exactly 2 moves
On page 6 of this PDF, it mentions the existence of a legal position such that whoever moves first must be checkmated in exactly 2 moves. Can someone please show me this position?
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Does this problem work under the standard AP condition?
[Title "André Hazebrouck. Die Schwalbe 47 10/1977 4. Preis"]
[FEN "r1b1k2r/P2p4/2p1n2p/ppPq4/1np5/p7/P2PP3/R3K2R w - - 0 1"]
а) h#2,5
b) h#2,5 (AP) 2 solutions
What is meant by ...
- 509
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Maximum saved moves to win caused by zugzwang
For a zugzwang where x>y and:
If white has the move, White can force checkmate in x full moves
If Black has the move, White can force checkmate in y full moves
The score of such a zugzwang is x-y....
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What conditions must/should be added to this fairy selfmate stipulation?
[Title "s#2 (?) Maximummer - Anatolii Vasylenko Die Schwalbe 132 12/1991 4. Lob"]
[FEN "1K2k2r/r4R2/8/QPp4p/8/8/8/8 w - - 0 1"]
1. bxc6ep Rxf7 2. Qxh5 0-0#
1. ...
...
- 509
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What is A Posteriori (AP)?
A number of problem-related questions recently mention AP by which they mean “A Posteriori”.
What are they talking about?
It seems as if the guys talking about it don’t have a common understanding. Is ...
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Can a unique position be deduced if pieces are replaced by checkers (can see piece color but not type)
Inspired by a video where top players guess which famous game a position is from, except pieces in the position are replaced by checker pieces (so they can see the piece color but not type). Of course ...
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Longest checkmates in (almost) fully covered boards?
What are the longest checkmates from initial positions which are (almost) fully covered in pieces? Down below I'll give examples of what I mean. An almost fully covered position can't be legal, ...
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One-liner double zugzwang
Can you construct a position on a single file (double your points if it is the a or h file, triple if position is symmetric) which is a mutual full point zugzwang?
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Can the problem condition "A Posteriori Type Keym", which flips the player to move, also flip the player that delivers mate?
Again, I composed the task, but doubts crept in. Is everything really as I think it is?
4k2r/4p3/4P3/7N/8/P7/rP1PP1P1/5KQR w - - 1 13
2b1k2r/1p1pp1p1/4P3/p6N/6P1/2P5/1PrPP1P1/1B3KQR w - - 1 13
...
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Have problems similar to this recent composition of mine been done before?
N1Nrk2r/n1ppp1p1/1pQ5/1P6/5R1P/3P3B/3PPBPp/R3K3 w - - 1 13
Checkmate in two moves.
AP (Type Keym + Type 3)
The AP Convention (A Posteriori) states: "If the player needs castling rights in order ...
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Who proposed that S stand for knight in English chess problem notation?
A small barrier to entry to the chess problem world is that knights are denoted "S" rather than "N". This confusing usage comes over as snooty and precious, but unfortunately we ...
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Longest checkmates with the biggest material disadvantages in "open" positions?
We can ask a question:
What are the longest checkmates with the biggest material disadvantages? What, approximately, is the function between length of the checkmate and possible size of the material ...
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Most delaying moves before checkmate
Consider a position where if was player A's turn, they could make a series of moves ("the mating sequence") with forced mate.
However, it is player B's turn, and they can make a series of &...
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Difficulty of problems for different rating levels
For club players, it is pretty well-known that certain types of problems are harder than others. Of course, mate in 4 is usually harder than mate in 1, but I am talking more about things like the ...
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What are the longest "golden sequences" in chess? (sacrificial middlegame attacks)
Initially, I was interested in the question "what are the longest sacrificial middlegame attacks?" ([Kasparov's Immortal] is one of the most famous sacrificial middlegame attacks). But this ...
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Is there a mate in two moves for white?
How is this a mate in two? I can't see it.
[fen "k4r2/1rQ1b1p1/2Rp1n2/1p2p2p/P7/1P3PBq/5P1P/4K2R w - - 0 1"]
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How many queens can check a king without it being checkmate (with no other pieces on the board)?
I am going to write an autobiographical story. The motive is therapeutic. I suffered abuse from my father, and at the age of 20, I developed delusional disorder; the psychosis lasted for 20 years, and ...
user36292
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Most mate options after 6 moves
Found this construction problem from '83 and liked it. I don't know the best solution (yet), and maybe you can top it anyway.
Consider the (help) "game" 1.e4 a6 2.Bc4 a5 3.Qh5 a4. Now White ...
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The 50 moves game
Play the longest game from the starting position such that each
move resets the 50 move rule (i.e. is a pawn move or a capture).
As I see it, each pawn quartet on adjacent lines has maximally 4+6+6+6 ...
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Longest *fairy* chess problem
Longest orthodox chess problem
One for the specialists. In the newest SCHWALBE I saw some titanic lengths (one problem had 2^59+2^57+3 ~ 10^18 moves!) As you see, this scales with O(2^(n^2)), where n ...
- 17.3k
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Max percentage of mating pieces
In the newest SCHWALBE, positions are given where any piece on the board can give a check (any being surprisingly high). A quick dabbling seems to prove that it is not possible that any piece can mate....
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Questions about legality of last move
Question for FIDE Arbiters and similar knowledgeable folk...
FIDE Law Article 5.1.1 The game is won by the player who has checkmated his/her opponent’s
king. This immediately ends the game, provided ...
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Most imbalanced (but equal) chess position?
I recently found this beautiful position, Position 11 where White sacrifices a bunch of material and then there are a bunch of crazy variations that all end in draws. For example this variation which ...
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What position has the most possible moves that all lead to being checkmated?
Inspired by this position from a game I played.
[FEN "r1b2rk1/p2p1p1p/2qb1PpQ/2p1p3/2p1P3/5N2/PPnP2PP/R1B2RK1 b - - 0 1"]
Black has almost all their pieces, is not in check, and can make 27 ...
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Is there a real version of the chess puzzle from The Yiddish Policeman's Union? If not - can it be made?
I will preface this by saying that the following contains a spoiler for Michael Chabon's The Yiddish Policeman's Union, so tread carefully.
Chess features heavily in the book and a major plot point is ...
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Searching games by chess positions
I have a somewhat weird question that is only indirectly related to chess. I am trying to solve a chess-related puzzle in which I have to find games played by Soviet chess players based on positions. ...
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A puzzle where you must find the mate in 3 solution but avoid mate in 2 and mate in 1 solutions?
I want to see if a puzzle could exist where you must avoid finding mate in 1 or 2 but just find the mate in 3 solution.
This is not subjective it is a hard math problem to make a move that forces mate ...
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Good chess puzzle that involves queen running around the board?
Do you have any good puzzles where the queen traverses across the board, which are ideally not too difficult or too many steps?
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Checkmate in ω² moves with finitely many pieces
The post Checkmate in ω
moves? has inspired a lot of discussion and mathematical research into positions on an infinite chessboard where white can mate in a transfinite amount of moves. The current ...
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Mate-in-N problems where N scales indefinitely with board size
Motivation - Long range mating patterns
This question is inspired by my recent interest in infinite chess and the post on MathOverflow Checkmate in ω moves?. Since my chess endgame skills are quite ...
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Grimshaw in practical (OTB) game
Does anybody know of an example of the Grimshaw-Theme being used in a practical game?
For the Nowotny there are several examples (e.g. Navara-Dergatschova, Ordix, 2007) and for the Plachutta there is ...
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Are there any hard mate-in-2 problems?
I'm interested to know if there are any particularly challenging mate-in-2 problems. Since the second move will be essentially forced, the problem essentially comes down to 1 move. Typically, the ...
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Longest sequence of moves where White's number of available moves does not change
There are challenges for the longest sequence of moves in which white's available moves increase or decrease. This challenge is for the longest sequence of moves (from the opening position) in which ...
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What is the longest sequence of increasing White moves with only White pieces?
Inspired by a comment by @Evargalo on this question, I ponder how long a sequence can last where each turn, White has more available moves than the previous turn, in a situation with only White pieces ...
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Is there a Chess 960 position in which White's moves can be decreased to zero without check?
Inspired by this question, koedem proved that, from the starting position, White's legal move amount can be decreased sequentially from 20 to 0 in 20 moves. However, doing so required some checks. I ...
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Longest sequence of moves where white's number of available moves decreases
An easier version of this
White has 20 available moves at the start of the game (from the standard position). After 1.h3 h5, white has 19 available moves. (The h pawn has lost the ability to move two ...
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Longest sequence of moves where number of available moves increases
White has 20 available moves at the start of the game. After 1.a4 e5, white has 21 available moves. (The rook has gained 2 moves, while the pawn has lost 1).
What is the longest sequence of moves ...
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Roundtrips with no shortcuts
In the picture, you see the longest roundtrip of a rook such that there are no "shortcuts" - imagine the target squares are given, then at each square you have exactly two other given ...
- 17.3k
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Move forcing opponent to checkmate in response
I was wondering if there was a move so bad in chess that if you played it the only move your opponent could do was checkmate you back, through blocking your piece or through moving the king. It would ...
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Longest sequence of unique legal moves for one player, always in check and ending in checkmate
I recently played a bullet game, in which I thought I was in checkmate, but then realized I had one legal move, this then repeated again and again 6 times until ultimately I was in checkmate. I share ...
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What is the maximum total number of piece points possible on the board?
Maximum number of non-pawn pieces on the board notes how to get the maximum number of non-pawn pieces on the board.
But what about the maximum number of points possible? It seems like this starts ...
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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 ...
