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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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 ...
0 votes
2 answers
385 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 ...
10 votes
4 answers
1k 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—of ...
13 votes
8 answers
3k views

Website or program that creates puzzles from blunders in your past games

I'm looking for a website or program that would look at your past games on Lichess or chess.com and find moves that you played that were blunders and create puzzles around those
4 votes
6 answers
7k views

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 ...
0 votes
0 answers
74 views

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 ...
14 votes
4 answers
1k views

Outside-the-box mate-in-one challenge

I've received an (I would say impossible) mate-in-one challenge and I have already checked all movements, but couldn't solve it yet. It came from a trustable source and they say you need to think ...
5 votes
2 answers
3k views

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"]
7 votes
4 answers
2k views

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 ...
2 votes
2 answers
135 views

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....
20 votes
4 answers
6k views

Is there a double-forced mate position?

A usual forced mate position is where the winning player can play in a way that ensures checkmate, no matter what (legal) moves the opponent makes (unless the game ends due to a non-play reason, i.e. ...
14 votes
4 answers
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?
11 votes
1 answer
430 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 ...
9 votes
2 answers
2k views

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 ...
4 votes
2 answers
191 views

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 ...
14 votes
3 answers
3k views

Maximum number of pieces on board in dead position

It is possible in a chess game to have a dead position in which both players have all eight pawns, one bishop, and a king--20 pieces total. If the two players' pawns are interlocked in "zig-zag" ...
5 votes
2 answers
379 views

Seeking a particular problem

I recall seeing a problem in Games magazine, probably in the early 1990s, that required the solver to deduce that a capture en passant was possible (not just because that's the only way to get a ...
16 votes
4 answers
4k views

Why are capturing key moves "frowned upon"?

Wikipedia's article on Babson tasks says: However, Yarosh's problem has a small flaw: the key is a capture, something which is generally frowned upon in problems. (The "key" of a chess ...
0 votes
1 answer
195 views

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 ...
7 votes
3 answers
670 views

Challenge: Create the longest game determined only by the final diagram 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 ...
2 votes
0 answers
91 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 ...
4 votes
2 answers
942 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 ...
18 votes
6 answers
32k views

Chess Problem Database with PGN or FEN

Is there a database of chess problems that have the game or positions PGN and or FEN?
5 votes
3 answers
292 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 ...
2 votes
2 answers
466 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'...
6 votes
2 answers
181 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 ...
4 votes
2 answers
514 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 ...
21 votes
4 answers
5k 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
0 answers
60 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. ...
11 votes
4 answers
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 ...
14 votes
7 answers
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 ...
14 votes
1 answer
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 ...
0 votes
1 answer
135 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 ...
0 votes
1 answer
70 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!
7 votes
4 answers
1k 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 ...
3 votes
1 answer
233 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 ...
14 votes
2 answers
735 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 ...
3 votes
3 answers
503 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 ...
11 votes
6 answers
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 ...
5 votes
2 answers
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....
4 votes
0 answers
100 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 ...
3 votes
2 answers
338 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 ...
9 votes
0 answers
734 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 ...
3 votes
3 answers
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 ...
-1 votes
1 answer
73 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 ...
6 votes
3 answers
241 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 ...
3 votes
1 answer
430 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, ...
2 votes
1 answer
62 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 ...
6 votes
4 answers
624 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
1 answer
98 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 ...

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