# 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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### Longest Sequence For Any Piece To Reach A Certain Square

What is the longest sequence of moves (by both White and Black) wherein White attempts to move one of their pieces from one square to another? Assume Black makes every move optimal towards the purpose ...
255 views

### What is the highest mobility score of a board without a checkmate, stalemate, or draw?

I consider the mobility score of a board to be the number of legal moves one player could make less the number of legal moves the other player could make. 8/7k/2Q2K2/8/6b1/8/8/8 w - - 0 1 Using the ...
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### 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 ...
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### Uniquely Satisfying Puzzle

Here is a fun puzzle I found some time ago. It was created by Karl Fabel in 1952 and published in Rätselstunde. Goal [title "White to move and NOT checkmate in one!"] [fen "B5KR/1r5B/6R1/2b1p1p1/...
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### Useful solving composed mate-in-2 problems?

I'm solving mate-in-2 puzzles from the Polgar 5334 problems book. Many of these are composed problems, and are hard (for me) to solve. Often I have to spend 10-15 minutes before finding the solution....
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### Longest possible game of Horde Chess

The longest possible normal game of chess has been calculated, but I want to know what the longest possible game of Horde Chess is. What makes this an interesting case is the crazy amount of pawn ...
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### Stalemate situation with all pieces on the board

Suppose all the pieces are on the board. Does there exist a position such that A) one of the players can't make any move (a stalemate)? B) neither player can make any move (a double stalemate)?
634 views

### List of famous, but incorrect, chess problems

Surely it has happened, that a famous chess problem turned out to be incorrect because some move was overlooked. Maybe a chess engine found out that a classic problem was incorrect! Is there a ...
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### How is the threat Qxh7 relevant here?

According to chess.com, "White threatens both Qxh7 and Qxf8 checkmate-Black cannot defend against both threats." Would the threat the white Queen has towards h7 be enough to have a checkmate? How is ...
• 259
700 views

### Pal Benko's final problem

EDIT: Link added One of my chess heroes, Hungarian GM Pal Benko, is no longer with us. He overcame many difficulties in his early life to live one which was rich and full, and reached the age of 91 ...
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### Does anyone have a version of the 50x50 article by Nikita Plaksin?

In 1979, Nikita M. Plaksin published a reportedly fascinating article containing 50 problems all related to the 50 moves rule. Unfortunately I can't find it anywhere, the only links that I could find ...
3k views

### Identify a problem where a potentially winning move draws because of the 50 move rule

I'm trying to recall a particular chess problem. It's related to retrograde analysis. All what I can remember is this: it's an endgame where there is only one way to reach the position, and during ...
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### From the start of the game what is the longest possible series of consecutive white moves where white can do those moves no matter what black does?

From the start of the game what is the longest possible series of consecutive white moves where white can do those moves no matter what black does? So I want the longest list of moves white can do ...
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### Attempting to create a retraction problem

I am trying to create a retraction problem, but I am unsure if it is sound, and I do not know where to find resources on them. I have two questions. Is my problem correct? I am not giving a solution ...
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463 views

### What is the record for the most stalemates in one?

Is there a known record for the most possible stalemates in one in a legal position, for with and without promoted pieces? I did some constructing myself for a start. For without promoted pieces, I ...
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273 views

### Looking for an old problem that I can't quite remember

I remember seeing a particular chess problem awhile ago on YouTube, but I can't find it. The problem's theme was something about caging in the Turkish king, and the video mentioned it as being old. ...
• 17.1k
1 vote
694 views

### The highest amount of moves by the losing side in a zugzwang

In zugzwang, the usual idea is to limit the number of moves that the opponent can make. But they can also have many moves in certain scenarios. What is the highest amount number of moves by the losing ...
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541 views

### Maximum number of ways to get out of check

What is the maximum number of legal moves in a legal position, given that the player is in check? It's easy to see that 43 is an upper bound. Let's suppose the white K is in check along a diagonal by ...
• 3,762
234 views

### Looking for an iPhone app for working out chess problems

I'm looking for an iPhone app that will allow me to set up a chess problem and work out its solution. I've seen apps that present me with a battery of chess problems but don't allow me to set up my ...
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### Where can I find these mentioned chess problems?

In his article “The Horse Concoction", Tim Krabbe mentions retrograde analysis problems that involve placing 10 rooks, knights, or bishops on the board for a mate in 1. The 10 rooks problem shown ...
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### 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'...
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### What is a pure checkmate?

Recently I heard something about pure checkmate. This is a special kind of checkmate where each of the squares around the king has to be covered by just one single piece. One simple example of this ...
5k views

### Endgame problem: How to avoid stalemate and win?

I'm stuck on this problem a friend shared with me recently, with barely any pieces left and apparently white is able to force a win but I've been hitting a wall with everything I've tried so far, as ...
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### Where is there a mate in four (pawn moves)?

From Fine's BCE: I can only see the pawn getting to a2 after 1.d6+ Kd8 2.e6 a4 3.Kf6 a3 4.e7+ Ke8 5.Ke6 a2 6.d7#. That's three pawn moves, not four. What is the more resistant defence I missed?
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### What is a “dual” in chess problems, such as the Babson task?

I’ve read up on Babson tasks, and they mention that all known tasks are not perfect because there are duals. I’m not sure what this means exactly. What precisely is a “dual” in chess problems?
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### What is the longest possible series of consecutive captures?

What is this the longest possible series of consecutive captures in a legal position? Here is an example of 25 on the same square, which is not required. [FEN "q1kr2q1/1qnqnb2/2prp3/q2pK3/2P1P3/...
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603 views

### Longest series of mutual "!" moves

Normally I'd pester the/a computer chess forum, but I couldn't register yet... On the Matplus chess forum, the following construction task came up. Both White and Black are on the brink of ...
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### What is the longest possible sequence of double checks?

The record for the most mutual checks in a legal position is known. But what is the record for double checks? There is one rule-threefold repetition applies. Four criteria exist-promoted pieces ...
• 17.1k
879 views

### An Interesting Idea: Pinned Pieces Stalemate

I had an idea for a type of stalemate: One side is stalemated with 8 pins in a legal position with as many pieces as possible, with all of the stalemating side’s units being “necessary.” ”Necessary” ...
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### What are the shortest possible games with a) 20 Bishops, b) 20 Knights, and c) 20 Rooks?

The fastest move sequence to reach 18 queens is known. Similarly, what are the shortest possible games with a) 20 Bishops, b) 20 Knights, and c) 20 Rooks?
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### Is there a chess AI that can force checkmate on a specified square?

I'm looking for a program that can force a lone king into checkmate on a specific square. Are there any programs out there that can do this?
478 views

### What is the highest number of forced checkmates in a legal position?

Having been inspired by a similar question, what legal positions have the most forced checkmates for one side and for both sides?
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### Looking for problems in which a KNN-K mate is forced

Does anyone know of any problems in which a KNN-K mate is forced in the end? It is fine if you make one yourself.
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### Resource for Chess Problems about particular topics

Most puzzles I find are where payout is relatively high. e.g mate in 2-3 moves, play right and get a piece etc. However, I needed a resource which gives me some puzzles/exercises about particular ...
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### Piece And Pawn Only Massacre Games

What are the fastest possible games in which only all pieces and all pawns are captured? I did some searching myself. Pieces Only [Title "me, chess.stackexchange.com 3/2/2019, Non-Unique Proof ...
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### Is this the quickest way to clearing the board to two kings? [duplicate]

Is 21 moves the least needed to get board down to 2 kings? [FEN ""] 1. e4 d5 exd5 Qxd5 Qh5 Qxa2 Qxh7 Qxa1 Qxh8 Qxb1 Qxg8 Qxb2 Qxg7 Qxc2 Qxf8 Kd7 Qxf7 Qxc1 Ke2 Qxd2 Kf3 Qxf2 Ke4 Qxf1 Qxe7 Kc6 Qxc7 ...
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371 views

### What is the fastest horizontal checkmate for both castlings?

I wish to know the fastest possible castling checkmate, both queenside and kingside, that is horizontal. See my question about vertical checkmates..
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### What is the fastest vertical checkmate for both castlings?

I wish to know the fastest possible castling checkmate, both queenside and kingside, that is vertical. See my question about horizontal checkmates.
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### Solvable studies that computers fail to crack

Are there chess studies that require an outside of the box thinking that goes beyond the concrete calculation capabilities of today's engines (e.g. Stockfish)? I have sometimes seen certain endgames ...
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785 views

### Is 6 the limit for the most pawns possible on a single file?

As far as I can calculate, 6 is the limit for the most number of pawns on a single file possible. Is 7 possible at all, ignoring promotion? I only took into account using the edge of the board, not ...
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633 views

### What are the quckest helpmates delivered by the rook, knight, bishop, and pawn?

What are the quickest helpmates, which is where both sides help administer checkmate to one side, delivered by the rook, knight, bishop, and pawn? The said piece has to deliver the checkmate on the ...
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384 views

### Black only has pawns: Mate in what?

In a standard opening position in chess, imagine that all Black pieces are removed except for the king and pawns. [FEN "4k3/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQ - 0 1"] What is the ...
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### Searching for a "where is the black king" problem

Sometime ago, a friend showed me a position where he had the Black king removed. The goal was to find where is the Black king using some pretty weird reasoning. There were only a few pieces on the ...
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### What is the theoretical maximal material difference of a dead draw which is not a stalemate?

I have noticed the following example, which should be a dead draw: I am wondering what is the theoretical material difference of a dead draw which is not a stalemate? (I am not asking about agreed ...
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1 vote
430 views

### Position with the largest material imbalance that is a draw, no matter whose turn it is?

I am curious if there is a known position with the largest material imbalance that, no matter who it is to move, the weaker side can hold a draw.
362 views

### What is the quickest way to reach a mutual, symmetrical stalemate?

What is the fastest known game that ends that in a mutual stalemate position that is symmetrical?
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### Can we say for sure that Black's king has not moved?

The following position appears as the 7th puzzle of Raymond Smullyan's Arabian Knights, a book about retrograde analysis. [FEN "3qk2r/p2pp1bp/bpp2n2/8/3N3Q/1PN1P1P1/P1PPP2P/3K1n2 w - - 0 50"]...
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### What are unsolved problems in chess? [closed]

Are there any problems in chess that remain unsolved?
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### What is the least number of knights needed to cover the entire board?

I’ve seen the solutions to the lowest amount of queens, bishops, and rooks are needed to cover an entire board, as in they can attack all squares and are the only type of piece on the board. What is ...
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