# 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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### A position with a choice between checkmate and perpetual check

For some odd reason I'm searching for a game, or rather a position, where one player can force a win via checkmate (can be check in n, where n is any number), but they can also force a draw via ...
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### What is the shortest possible legal game where there are 6 pawns on the a-file or h-file?

I was recently reading a post on this forum which said that there must be 15 captured pieces in order for there to be 6 pawns on the a-file or h-file. That got me thinking how complicated that would ...
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### How long can a player hold off a draw by the 50-move rule?

Going by rules strictly about the board state, how long can a player theoretically hold off a draw by the 50-move rule? White will play as long as possible, and not want to lose. Black will claim a ...
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### How many times can the king and its surrounding squares be attacked?

In a legal position, how many times can the king and its surrounding squares be attacked? There is a total of 9 possible squares to be attacked-the square the king is on and the eight squares ...
• 505
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### 32 pieces protected once: How many moves?

From the orthodox starting position, how many moves will you need to have the 32 pieces protected exactly once? (The answer is astonishingly low.)
216 views

### Shortest game controlling a single square 16 times?

Does someone know the shortest orthodox chess game such that a single square is directly controlled 16 times? After 1. Nf3 for instance, the square d2 is controlled 5 times. And 2. ... Qa5 pushes the ...
235 views

I am looking for a good chess website about retrograde analysis problems, but after a few searches, I haven't found anything. Are there any websites that you can recommend?
209 views

### 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 ...
153 views

### Which White piece moved only once?

Here is a chess problem that uses retrograde analysis. I’ve also posted it on the “France-Echecs” chess forum, which is in French of course, and on my blog. [FEN "3qk3/3pp3/8/8/8/3PP3/1PP2PP1/...
906 views

### Systematic ways to approach more difficult problems

As I’m done solving easy puzzles (1000–1500), I decided to try some 1700 puzzles, but I’m finding it very hard to solve them as there are no obvious checks, captures and threats. Also, most of the ...
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### Maximum number of knights populating a chess board so that no knights are attacking one another

The 8 queen's puzzle is a well-known puzzle involving placing 8 queens on a chessboard so that no queen attacks another queen. It is more or less obvious that 8 is the maximum number of queens that ...
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### Chess problem by A. G. Kopnin - Russian notation explanation needed

[Title "Alexey Grigorievich Kopnin - mate in two - 1948"] [FEN "nR1rB3/2PPPN2/bbk1N3/1p2p3/1p2P1nq/1K1Pp3/7B/8 w - - 0 1"] (source) In this problem, it’s white to move and mate in ...
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### Pinning Combination

There are are four types of pins. Absolute Pin-A piece is pinned to the king and cannot move due to the resulting illegal check. Partial Pin-A piece is pinned to the king and can move along pinning ...
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### 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 ...
2k views

### Forced mate: 2 queens vs king

On the board, there are 2 queens (of the same color) placed on random squares. The opposing side has only a king, placed on a random square (and not in check). There obviously exists a mating sequence....
• 411
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### What is the maximum number of checked squares on a board that delivers checkmate without a draw?

I’ve long dreamt of delivering a “super checkmate”. Imagine that as his dying wish, when in checkmate, the king can magically transport himself to any open square on the board. What is the board ...
• 171
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### What is the longest checkmate problem a human has composed?

Well, I looked at some long checkmates, and I wonder, what is the longest checkmate a human has composed?
216 views

### Which legal position has the smallest number of moves in a "forced loop"?

Consider this (illegal) position. [FEN "5n1k/3p1p1p/3PpPpP/4P1P1/1p1p4/pPpPp3/P1P1P3/K1N5 w - - 0 1"] If we do not consider the position's illegality, and the fact that it is clearly ...
• 192
1 vote
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### What is the theoretical maximal total of material for the insufficient material draw? [duplicate]

The insufficient mating material rule says that the game is immediately declared a draw if there is no way to end the game in checkmate. This usually happens in KB vs K or KN vs K endgames. However, ...
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### Infinite sequence of consecutive checks allowing more pieces (say 9+ queens)

This is a task related to this question: Theoretical limit for the number of consecutive checks?. By a sequence of consecutive check, what we mean is white giving check, black replying with a check, ...
• 1,321
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### How much material is needed to force the capture of a lone queen (for example in horde chess)?

In horde chess, the following starting position is used: [FEN "rnbqkbnr/pppppppp/8/1PP2PP1/PPPPPPPP/PPPPPPPP/PPPPPPPP/PPPPPPPP w - - 0 1"] The goal of White is to checkmate Black; the goal ...
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### Calculating the precise number of combinations of possible moves from a given position

I was surprised Bobby Fischer couldn't find a mate in 3 within 30 minutes in this problem by Pal Benko. This made me wonder-how many actual moves are possible with so few pieces left in only 3 moves? [...
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### Can White defend and possibly win?

[FEN "1nkr2nr/pppp2pp/2b2p2/3q4/3P4/1NQ5/P1P2PPP/R1B1R1K1 w KQkq - 0 1"] Can White possibly win in this position and avoid a queen mate on g2?
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### 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 ...
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### What’s the difference between Partial Retrograde Analysis and Retro Strategy?

What’s the difference between Partial Retrograde Analysis (PRA) and Retro Strategy (RS) which are different ways of interpreting retrograde analysis chess problems?
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### Maximum number of quiet moves in a position

The question of how many captures a position can have has been asked in the past: Maximum number of captures in a position Without captures, and without promotion, which I define as “quiet” moves, ...
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### How many queens can be on the board without neither forced mate nor forced stalemate (53?)?

I was wondering how many queens can be put on boards without the position being a forced checkmate or a forced stalemate. The best I came up with is 53 this position. [FEN "QQQQQRK1/QQQQQPr1/...
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### How are ratings determined for training puzzles on lichess.org? [duplicate]

On lichess.org, how are the ratings for the tactical puzzles computed? I am trying to understand how some puzzles I find challenging are as low as the 1400s, while others that seem obvious are at ...
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### Why is Ne2 better than Nf3?

I played Nf3 for attacking on king side which is about to castle having some plans to make a battery in future after castling but I feel Ne2 is making a block for Re1 at some point. Any suggestions? [...
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### 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&...
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### Which piece combinations can mate a lone king without being aided by the attacking king?

Clearly not a practical question since the king can and should be used in the endgame, but I was curious if anyone has done a comprehensive analysis of which combinations of pieces (including some ...
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### 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. ...
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### Gyula Breyer joke composition cooked?

I recently bought the delightful book Outrageous Chess Problems by Burt Hochberg, which among other things contains some interesting joke compositions. I have a question about Problem 102 (diagrammed ...
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### What moves solve this mate in 2?

It’s White to move and mate in 2 moves. [FEN "7r/1p3Q1p/2q5/3bk3/1Q2p3/2P5/r2P2PP/2KR4 w - - 0 1"]
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### How can I prevent checkmate in this position?

It is White's turn to move. How can White avoid a checkmate? [FEN "8/1kpP2q1/1p2P1p1/1P3pP1/5p1K/5P2/6P1/R7 w - - 0 1"]
• 307
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### 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 ...
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### 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 ...
443 views

### Problem with a shorter solution

I'm looking at this problem. [Title "White to move. Mate in three"] [StartFlipped "0"] [fen "5rb1/1p1P1pbr/1p5p/5N/PP2k/1Np3QB/6K/8 b - - 0 1"] It requires white to mate in three. The accepted ...
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### A chess problem: White to play and mate in two

White's turn, checkmate in two moves [FEN "r1b2k1r/1p2bppp/p1B2q2/8/8/8/PPPQ1P1P/2KRR3 w - - 0 1"] How does White deliver checkmate in 2 moves?
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[FEN "5K2/k7/4P1p1/8/8/8/4b3/8 w - - 0 1"] A friend of mine is challenging me to find a solution. It’s White to play and DRAW.
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### 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 ...
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### Checkmate via en passant capture [duplicate]

I tried to get the smallest sequence of moves that would result in a checkmate*( or rather Helpmate)* with the last move being a en passant . This is the shortest I could get : [Title "Shortest En ...
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### Chess Problem: Reset The 50-Move Rule!

While chess problems and such are usually meant for Puzzling Stack Exchange, I thought that this one should be an exception since it’s more relevant IMHO. Resetting the 50-move rule, i.e. restart the ...
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### What is an example of a very difficult one-move checkmate? [closed]

Usually one-move checkmate puzzles are easy. However, I am wondering if there is a relatively more difficult one-move checkmate puzzle. Here are a few thoughts: There are many legal moves. One or ...
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### Is there a way to prove a checkmate in 3 problem is not solvable?

I have been working on a checkmate-in-3 problem for a long time. So long that I am becoming convinced it is not solvable. Is there a way to prove it is not solvable? I want to avoid putting the ...
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### What rearrangent of the starting position's pieces, in any manner, has the fastest stalemate?

It is well known that the fastest stalemate is in 19 ply. But what is the fastest possible if all pieces, not pawns, may be shuffled at will on their first ranks? This will be difficult since there is ...
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### Is the "Pawn Box" possible in standard chess?

Is it possible to create a "pawn box" as shown below (using legal moves and the help of black) in standard chess? The positions don't need to be exactly as shown, and there can be more pieces on the ...
• 1,284
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### Why does the black king evade to f8, and not to h7?

I'm trying to practice with the app https://f-droid.org/en/packages/jwtc.android.chess Why does the black king go to f8, and not Kh7 instead? [FEN "r2rb3/1p2RBk1/2pP1ppR/p7/P7/7P/1q3PP1/3Q2K1 w - - ...
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### What is the highest value of pieces on this particular 6x6 board, without any of them attacking each other?

I got a question in school in which I have to get the highest score possible by adding pieces on a 6x6 board like this: The rules are that they are the same color and may never attack each other, and ...
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