# 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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### Chess Problem Database with PGN or FEN

Is there a database of chess problems that have the game or positions PGN and or FEN?
848 views

### Castling vertically problem

I've once saw a joke chess study about castling vertically. However, I have forgotten who has composed it. I remember that in the positions, all the pawns were locked, but not much else. Does anybody ...
269 views

### 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 ...
461 views

### A question regarding "The Horse Concoction"

Long ago in 2000, Tim Krabbe presented, a now classic, problem by Harry Goldsteen in his article “The Horse Concoction” on his site. It has blossomed across the Internet, as some of us know. The task'...
175 views

### 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 ...
484 views

### 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 ...
861 views

### Positions that stump engines

Chess engines are so strong that it is becoming increasingly hard to find positions that they are demonstrably evaluating incorrectly. I'm interested in collecting examples—if there are any&...
4k views

### What is the theoretical limit for the number of consecutive checks?

The known record for the longest sequence of consecutive checks (i.e. white checks, then black checks on the next move, white checks next, and so on) in a legal position without promoted pieces, is 37....
1 vote
51 views

### 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. ...
3k views

### Difference between chess puzzle and chess problem in this episode of The Queen's Gambit?

While a chess puzzle is any puzzle involving aspects of chess, a chess problem is an orthodox puzzle in which one must play and win or draw a game, starting with a certain composition of pieces on the ...
3k views

### Arrange 5 non-attacking knights on a 5x5 toroidal board

The celebrated British mathematician and lover of public transport, Simon Norton, passed in 2019. He was the subject of a wonderful biography. He was not a particular fan of chess, but here is a tiny ...
3k views

### 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 ...
332 views

### Open problems in chess involving maximum material imbalances

I am posting the present question since here Very unbalanced Chess Positions I have introduced three open problems (i.e., the third one, the fourth one, and the sixth one from the above), regarding ...
123 views

### 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 ...
62 views

### Good chess puzzle that involves queen running around the board?

Basically title. Ideally not too difficult or too many steps, but if you have any good puzzles where the queen traverses across the board. Thanks in advance!
961 views

### What is the highest number of pieces from one side that can be involved in a checkmate?

What is the highest number of pieces from one side that can be involved in a checkmate? "Involved in a checkmate" is defined below. A non-king piece is involved in a checkmate 'if removing ...
344 views

### Checkmate with only relevant pieces

What is the maximum number of black and white pieces which are relevant in a checkmate position (by White)? That is if any piece (black or white) was removed from the board, the checkmate would not be ...
213 views

### 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 ...
725 views

### If repetition loses, who wins KvK?

Suppose we're playing a version of chess where you lose if you repeat once an earlier position (position = arrangement of pieces + who's move it is). We're down to the wire, and we've just arrived at ...
499 views

### Puzzles that highlight the finiteness of the chessboard

I'm curious as to whether there are compositions of chess puzzles/problems where the solution really emphasizes the boundedness of the board. Put differently, cases where the solution would be ...
2k views

### What kinds of unconventional chess problems exist?

What are some unconventional chess problems that ordinary chess engines can never solve? I'm attaching two examples below so that you can get an idea. My students seem to love these puzzles. I'm ...
3k views

### How many times can the same pawn move be made in a game?

How many times in a game can "the same pawn move" be made? By "the same pawn move", I mean, a move made by a pawn that would be notated the same way. For instance, after 1.e4 e5 2....
99 views

### 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 ...
240 views

### 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 ...
727 views

### A fun game (for problem composers, mostly...)

A game leading to a given position is called a proof game. Of course any proof game can be prepended with 1.Nf3 Nf6 2.Ng1 Ng8, so we defined a shortest proof game as, duh, the shortest possible proof ...
166 views

### Forced Mate (differently)

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 ...
71 views

### 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 ...
63 views

### 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 ...
226 views

### 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 ...
424 views

### Longest sequence of forcing moves?

What is the longest fixed consecutive series of moves for one player such that the other player's response is forced every move? Assume draw rules must be obeyed (threefold repetition, 50-move rule, ...
61 views

### 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 ...
618 views

### 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 ...
1 vote
96 views

### 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 ...
4k views

### What is the shortest possible game with 18 queens?

This question demonstrates a game in which all 16 pawns promote for a total of 18 queens on the board. It takes 80 moves... What is the shortest sequence of moves that achieves this goal?
570 views

### Challenge: Create the longest set of moves where the game is able to be perfectly reproduced from only the current board state and move number

The challenge is to create the longest list of half moves whereby an AI could re-create that list of moves perfectly, only given the ending board state and the number of moves. As example I will first ...
584 views

### Mate in One the Missing King

The post "A mysterious mate in one" made me think of one of my last problems which is also a Mate-in-One with no black King: [Title "White to move and mate in one"] [FEN &...
237 views

### 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 ...
256 views

### 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 ...
10k views

### When was it possible for a player's king to be attacked by 3 of the opponent's pieces?

According to the current FIDE Laws of Chess: 3.9.1 The king is said to be 'in check' if it is attacked by one or more of the opponent's pieces, even if such pieces are constrained from moving to ...
163 views

### 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 ...
1k views

### 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 ...
3k views

### THE longest problem ever (much longer than the mere 549 mover...)

The "Fireside Book of Chess" by I. Chernev and F. Reinfeld includes the following diagram [fen "3nk3/3NN3/3PP3/3BB3/3PP3/3PP3/3PP3/2RQKR2 w - - 0 1"] Composed by J.N. Babson for ...
1k views

### 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 ...
517 views

### What is the largest n such that discrete forced mate in one through mate in "n" exist?

This is admittedly a bit of an obscure question, so I apologize for the awkward wording of the question. To begin, assume you are playing as White, and that a "forcing move" is any move that ...
216 views

### A little Silvester puzzle

A regular game has been played where White still has all 16 pieces. White promoted only a single pawn, and not to queen. In the final position all 16 pieces of White have (at least) one mating move. ...
3k views

### Basic "mate in one move" puzzle - what am I missing?

I am extremely new to chess and have been working through some "mate in one" problems on chesspuzzles.com for practice. This one has me very confused though: The stated answer is: But why? ...
1 vote
196 views

### Piece Peace Puzzle

Place the whole army of White and the black king on the board, such that no piece is attacked or defended. (Obviously you must use double pawns.) That's fairly easy, so tie breaker will be how many ...
153 views

### How many unoriginal pawn moves can be made in a single game?

Consider an "unoriginal pawn move" to be a pawn move whose notation matches a move already played in the game. For instance, after 1.e4 e5 2.d4 exd4 3.e5, there is one unoriginal pawn move, ...