# 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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### Is Behting Study Still Beating Computers?

This is the famous Behting study, first published in the magazine Bohemia in 1906, which is often used as a demonstration that computers can’t solve all positions. White to move and draw with a very ...
242 views

### 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 ...
182 views

### 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 ...
116 views

### 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 &...
658 views

### What is the fastest possible stalemate by castling?

It is known what the fastest stalemate is. But what but is the fastest possible stalemate in which castling must be the last move? 33 plies is my best result so far. [FEN ""] 1. e4 h5 2. ...
85 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. ...
62 views

### 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 ...
396 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 ...
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 ...
4k 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
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 ...
84 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 ...
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 ...
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"]
3k 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 ...
137 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....
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. ...
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?
439 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 ...
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 ...
205 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 ...
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" ...
384 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 ...
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 ...
206 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 ...
684 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 ...
94 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 ...
963 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 ...
33k 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?
300 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 ...
468 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'...
184 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 ...
528 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 ...
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....
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 ...
140 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 ...
71 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!
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 ...
253 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 ...
747 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 ...
505 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....
101 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 ...
406 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 ...
741 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 ...