Questions tagged [problems]

Chess problems consist of 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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2
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1answer
54 views

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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2answers
2k views

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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2answers
116 views

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 ...
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3answers
150 views

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.)
2
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1answer
129 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 ...
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2answers
60 views

Retrograde problem websites

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?
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0answers
79 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 ...
4
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1answer
122 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/...
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3answers
795 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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2answers
2k views

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 chess board so that no queen attacks another queen, and it is more or less obvious that 8 is the maximum number of queens ...
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2answers
692 views

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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1answer
70 views

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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1answer
80 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 ...
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1answer
1k 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....
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1answer
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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 ...
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1answer
247 views

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?
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1answer
62 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 ...
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0answers
62 views

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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0answers
22 views

Examples of Debunked Problems [duplicate]

Are there any problems that have solutions which have been debunked?
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115 views

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, ...
5
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1answer
100 views

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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1answer
85 views

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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3answers
410 views

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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1answer
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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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1answer
49 views

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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1answer
70 views

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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1answer
307 views

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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0answers
25 views

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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5answers
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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? [...
8
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1answer
188 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&...
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2answers
260 views

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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1answer
107 views

What is the fastest possible stalemate by castling?

It is known what the fastest stalemate is. But what but is the fastest possbile stalemate in which castling must be the last move? 33 ply is my best result so far. [FEN ""] 1. e4 h5 2. Qxh5 d6 3. ...
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1answer
173 views

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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2answers
3k views

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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4answers
4k views

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"]
9
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2answers
295 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 ...
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2answers
248 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 ...
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1answer
418 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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4answers
358 views

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?
23
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1answer
3k views

Please help solve this endgame problem posed by a friend

[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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1answer
187 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 ...
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1answer
85 views

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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2answers
173 views

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. Reseting the 50-move rule, i.e. restart the ...
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1answer
205 views

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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2answers
145 views

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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2answers
187 views

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 ...
14
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3answers
5k views

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 ...
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1answer
2k views

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 - - ...
2
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1answer
162 views

What effects would being able to capture while castling have?

Capturing an enemy piece while castling has been illegal for many decades, and the concept has been solidified in chess history. But what effects would it have if it were allowed? First, some ground ...
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3answers
158 views

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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