Questions tagged [retrograde-analysis]

Retrograde analysis is a technique employed to determine which events occurred leading up to a given situation.

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The Rook's Hassle

Long ago, the Black rook was trapped, stuck on c4, sapped and sacked. Let us unwind its snarly woes, and stop the clock. Turn back the flow, find out how long ago, to the original dock. How many moves ...
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5 votes
2 answers
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A Complicated Exercise In Addition

Another day, another walk down to the cafe. I was waiting in line for my coffee, wondering what the barista could do this time to make my name look whack. But as I waddled in line, a curious site ...
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4 votes
1 answer
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Guess the algorithm

Here you are seeing part of a pattern I created with my computer. Can you either reproduce it or describe the algorithm I used?
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2 votes
3 answers
504 views

How old is Grandfather?

This position has been used in hundreds of chess problems for various reasons by a plethora of problemists over many, many decades. It is known as "Vielväterstellung" in German, or "The ...
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3 votes
3 answers
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Chess Construction Challenge #9: Two Eggs & A Flood

I have an odd idea for this challenge. It involves a very specific proof game construction. So pay attention! Given that: White and Black cannot move more than one pawn each throughout the entire ...
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3 votes
1 answer
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Chess Construction Challenge #8: Three Times The Charm

On a chessboard, a piece has a set number of legal moves. It can range from 0 to 27. However, this amount can also restricted. My previous questions have covered n=1 and n=2, it is time for n=3! Given ...
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7 votes
3 answers
528 views

Chess Construction Challenge #7: Double The Fun

Many thanks goes to @Retudin in a comment on my last question for this idea. In a chess position, pieces can be restricted as to how many moves they can legally make in theory. Since my previous ...
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9 votes
5 answers
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Chess Construction Challenge #6: The One Move Royale

In chess, it is possible for a piece to have only one legal move. For example, in this position, the Black king can move only to h2. Given that: All 32 pieces are available for use. Construct: A ...
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11 votes
2 answers
762 views

Never kill your king ... without first seeking proper legal advice!

This is a follow-up to (Almost) all hands on check by @loopy walt. The task (mate in one with as many essential pieces as possible) stays the same, but you are to go about it more cunningly. Recap of ...
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6 votes
2 answers
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May White Castle?

Quite simply, may White castle in the below position? There is much more than what meets the eye! For the record, White pawns move up and Black pawns move down. Nikita M. Plaksin & Michel Caillaud,...
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0 votes
1 answer
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Mirror Mirror On The Board

Mirror mirror in the board Decipher the riddle of this horde How many moves to it, please? To put my brain at ease! Both sides help, follow their paths The solution you must craft Oh, and there is but ...
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6 votes
1 answer
327 views

An intriguing game construction

I found that the book "Amusements In Chess," by Henry Ernest Dudney, has been morphed into a website. In the section "Various Chess Puzzles, I came across this particular puzzle that ...
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2 votes
1 answer
216 views

Going back the the dance floor

Johnny, the White monarch, is homesick, and his friend Carla, the h1 rook, is away, using her time to help the lower citizens of the Black kingdom. They use to do such wonderful fun, but their ...
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7 votes
2 answers
644 views

1x1x1 Rubiks Cube Puzzle

The solved position of 1x1x1 Rubiks cubes as shown was shuffle rolled without moving outside the 4x4 puzzle grid. All cubes are similar with face opposite colors: red to magenta,green to yellow and ...
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8 votes
2 answers
310 views

An Enigmatic Game

I have a fun-ky puzzle for everyone today. Here is the position. FEN-rnbq1rkb/ppp1pp2/5p2/8/8/4K3/PPPPNP1P/RNBQ1R2 It can be reached in one way in exactly 9.5 moves, or 10 White and 9 Black moves. ...
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4 votes
1 answer
154 views

Homeworlds: Mercury in Retrograde

Consider the following position in a game of Binary Homeworlds. ...
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5 votes
2 answers
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Who shall be the winner?

There are two questions to answer here: Who will win this game of chess? What were the last 96 individual moves (ply) by both sides? The solution is unique. Gyula Breyer The Chess Amateur 1922, ...
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7 votes
4 answers
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What was the last move made in this game?

What was white's last move in the game shown below? Note: This is a screenshot taken from an actual game and all moves made were legal. ETA: The last move played by white was the last move of the ...
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9 votes
3 answers
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Where art thou, oh native rooks?

Here’s a tough puzzle for you all today! Given that both White and Black conspired to reach this position as briskly as possible, where standth White’s native rooks (the one from the starting ...
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7 votes
2 answers
458 views

A Simple Question

May White mate in two? Good luck! Thomas Rayner Dawson, Tidskrift för Schack, 1923 Major Hint:
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15 votes
3 answers
2k views

Only one square for the white king

Consider this position. It is white's turn to move. Your job is to place the white king so that white have an overwhelming (winning) advantage. Where is it? Please note that: While Queen usually ...
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4 votes
3 answers
340 views

Judge this position

An odd chess crime has occurred. The below position, a criminal one, was on the board when it was intercepted. Is it a legal or illegal chess position? Give reasonable proof as to why. You are to ...
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9 votes
3 answers
490 views

So, what's to do?

It's White to move and draw the game. What must White do? You must provide proof for your claim of what's to be done by any reasonable means. No looking up the solution please! Nikita M. Plaksinm ...
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25 votes
3 answers
5k views

A Checkmate of Dubious Legality

Full-size image Black has just delivered checkmate in the above position - but is the position legal? If no, explain why. If yes, give Black's mating move. FEN: 3r4/2r4b/8/8/8/3Kp3/5k2/8 w - - 0 1 ...
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10 votes
1 answer
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Reverse dots and boxes – Guess the last move

Alice and Bob are playing a game of reverse dots and boxes. The players take turns adding one horizontal or vertical line of size 1 in one free spot on the grid (marked with light gray lines ...
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2 votes
4 answers
233 views

Find Those Chess Notations! #7

It's been awhile, so welcome to my series if you haven't seen it before! Number Of Moves: 15 Checkmater: Black Given Game: ? ? ? ? ? ? ? ? ? fxe3 ? ? ? ? ? ? ? dxe4 ? dxe6 ? ? ? ? ? fxe5 ? ? ? ...
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18 votes
4 answers
2k views

White's last move?

You guys have proven to be quite capable chess detectives. So here is one more mystery for you to solve: What was White's last move?
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98 votes
4 answers
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Checkmate in 1 on a Tangled Board

Lots of pieces are tangled here. Can you find mate in one? Small hint to guide you in the right way:
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16 votes
3 answers
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Can White Castle? #3

Since it seems at least some people are enjoying these I'm continuing the series. This one is not quite as elegant, but still interesting. Can White Castle?
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17 votes
1 answer
688 views

Can White Castle? #2

Following on my previous puzzle that was well received (here).Note that this one is a lot shorter / easier, so feel free to participate! Can White Castle?
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82 votes
3 answers
9k views

Can White Castle?

This is the first chess puzzle I composed in the retrograde genre. I originally posted this in a chess dedicated forum. Hope you like it! In the following position, is it possible that White could ...
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0 votes
1 answer
381 views

Where is the White King? [duplicate]

I recently stumbled upon this puzzle on a known video platform. Apparently it's from the cover of an old book named "The Chess Mysteries of the Arabian Knights". The white king made himself ...
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2 votes
2 answers
275 views

Place The Black King Legally-Two Solutions

Warning: If the wording seems cryptic to you, that’s because it is meant to be. Here’s a puzzle for you: legally place the black king in the following diagram. Additionally, assuming that all white ...
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2 votes
1 answer
135 views

Find Those Chews Notations! #6

Here be a hearty return to the original point of this series: retrograde analysis! Number Of Moves: 12 Checkmater: White Given Game: ? ? ? ? ? ? ? 0-0 ? ? ? ? ? ? Nf6+ Kh8 ? ? ? ? Nxf5 ? Ng6# ...
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6 votes
1 answer
364 views

The Not So Knights Challenge

You have been imprisoned by your super duper cliché evil king named Tim Goldsteen for sneezing during his birthday party. Apparently he’s that evil. Anyhow, you found out Tim’s secret that he enjoys ...
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3 votes
1 answer
318 views

That Ain’t Right.... #3

Here’s a simple challenge. With black to cooperate and move first, and white to checkmate, checkmate black in 6 plies (half-moves.) Only one illegal move may be made, and white makes only legal moves. ...
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6 votes
2 answers
281 views

The Fastest Way-A Challenge

This is my first “find the fastest way to this position” chess puzzle” here on PSE. However, this is not for just some random position. Let me explain. Tim Krabbe has said on his site (Journal Entry ...
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15 votes
4 answers
2k views

Tht Aain’t Right... #2

I already have another, probably very easy, for you all again! Task: State the rule/s that you believe are being broken based on the position and/or what clues I have/you think are being given. You ...
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4 votes
1 answer
259 views

That Ain’t Rght... 1# (Definitely!)

Many chess problems are dedicated to legal games, and very few to illegal ones. So I’ve decided to start another series of the latter! Every problem I make will have some offbeat thing about it that ...
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6 votes
2 answers
148 views

Find Those Chess Notations! #4

Yes, it’s back again! This one is going to be a little different however. Number Of Moves: 11 Checkmater: White Final Position: Cryptic Clue #1: Not all is as it seems! Cryptic Clue #2: Are ...
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3 votes
1 answer
115 views

Find Those Chess Notations! #3

I’ve decided to do something a little different this time. I’m going to give you nearly all of the moves of one side, and must figure out the rest of the moves of the other side. Variations are ...
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6 votes
1 answer
175 views

Find Those Chess Notations! #2.5

Yet again, just another small one that I created before the next big one sometime tomorrow! Number Of Moves: 7 Checkmater: White Given Game (Regular Chess Notation): 1. ? ? ? ? ? ? ? O-O ? g5 ?+ ? ...
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8 votes
1 answer
167 views

Find Those Chess Notations! #2

Alrighty, it’s time for round two, as I promised! It’s a challenging one alright, I believe! Number Of Moves: 17 Checkmater: Black Given Game (Regular Chess Notation): ...
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4 votes
2 answers
445 views

Fantastic Foxhole Failures

I have decided to make a little bit of theme for this next chess question. And that theme is foxholes in war. Makes sense to me since chess is a technically a war-themed game. I have two puzzles for ...
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6 votes
1 answer
120 views

Find Those Chess Notations! #1.5

This is this a small puzzle for you all until I come out with a big one for #2. Number Of Moves: 6 Checkmater: White Given Game (Regular Chess Notation): ? ? ? ? bxa3 g6 ? Ne7 ? ? Nh6# Cryptic ...
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7 votes
1 answer
227 views

Find Those Chess Notations! #1 (Probably)

I’m hoping to begin a mini-series where you will have to figure it’s the entire notation list of a game being given a few moves, a few cryptic hints, and the number if if moves, and which side gets ...
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6 votes
4 answers
503 views

Backwards pawns

Part One: Reach the above position from the starting position Part Two: Find the fastest way to get to this position. Answering part one will get you an upvote, answering part two gets the checkmark!
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7 votes
1 answer
300 views

An Atomic Proof Game

One day, I heard two of my friends were playing an online game of chess. I went to spectate, and this was the position: However, I looked at the move list, and realized White's sixth move had just ...
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11 votes
3 answers
520 views

Loser Chess : another proof game

After this puzzle has been solved, it is time to offer our clever solvers another Loser Chess game to reconstruct... Do you remember that I often pay a visit to my friends Fabi and Mag on evenings ? ...
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9 votes
1 answer
395 views

Paper, pencil and a bunch of bars

An entry for the Fortnightly Topic Challenge #40. Alice and Bob are two rational players who are playing a simple pencil-and-paper game. In the beginning, there are fifteen small vertical bars on ...
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