user5653: 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 researching and learning about it now. Thank you in advance.


Example 2

EDIT

Thanks @ETD for pointing out that it's possible to create programs to solve, at least by brute force solutions to any chess problems. What I mean though is normal chess computers.

EDIT 2: I realize that the question is a bit vague. What I really like to know is creative puzzles, which if given to a beginner player should not be solvable by putting it on his computer and running an analysis.



user11629: Apart from non-standard problems (fairy chess, retrograde analysis, etc), there also exist particularly difficult regular chess problems which are used for testing chess engines, like Nightmare II. These might not be solvable by some engines/computers. Take a look at this list 

user8860: Try also Burt Hochberg's Chess Braintwisters,
which often require "thinking outside the box" to a move that is
logical but illegal (like promoting to a King) and thus would never
be found by an ordinary chess-playing or problem-solving computer program.
A couple of examples from that book have already been posted in this forum
in reply to another question: Is there any position where not promoting(illegally) would be the best move?

user3819: There is a branch of Problem Chess called Fairy Chess Problems with all kinds of stipulations.
However, there are specialised programs (e.g. Alybadix or Chloe/WinChloe) to solve fairy chess problems and nowadays problem composers routinely use them to verify the integrity of their creations. For more information, look at https://en.wikipedia.org/wiki/Software_for_handling_chess_problems

user1485: Here is a fun puzzle:
Construct a legal chess game where

white starts with 1. a3,
white delivers checkmate on move 5, and
the last move is made with the rook that started on a1.


 Hint: Black takes the pawn on a3.


user9030: This is an excellent source for problems from different range of difficulty, where you can find these types of problems:

Selfmate
Helpmate
Reflexmate
Retrograde Analysis

Which regular chess engines can't solve because solutions are not the best moves. (Actually, worst moves in selfmate problems for example)

user15989: I will do the obligatory retro and proof game plug:
Proof games
A type of problem where you are to reach the diagram position within a given number of moves.
A good introductory PDF by Alain Brobecker, featuring many "classic" problems that are well-known among the proof game community.
Jeff Coakley has a lot of shorter (but still tricky) 4-move proof games on chesscafe (although the site put them behind a paywall since 2014, the resourceful reader can probably figure something out...)
Another simple example (original by me): Reach the position after black's 4th move.
rnbqkbnr/1ppppppp/8/p7/3P4/8/PPP1PPPP/RNB1KBNR w - - 0 1

Shorter proof games of about 4 to 7 moves are pretty good for regular chess players, and you literally only need to know how the pieces move. Longer ones can go up to 30 moves (for a "normal" long proof game) or even over 180 moves (the longest I know of).
Retrograde analysis
Given only the diagram position and the fact that it was reached in a legal chess game, determine some feature of the position like side to move, castling rights, en passant rights, whether a piece is promoted...
An excellent collection of simpler problems that slowly rise in difficulty.
A magnificent introductory text by Nikolai Beluhov, an excellent composer of such problems. (Link is to a post containing PDF attachment.)
Another easy example by me again (although the idea is not new): What was the last move played? (I don't even need to give you the side to move for you to solve it.)
8/8/8/8/8/4PP2/1PPPRKPk/4nQ2 w - - 0 1


5653: <p>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 researching and learning about it now. Thank you in advance.</p>
<p><a href="https://i.stack.imgur.com/ObQJh.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ObQJh.jpg" alt="Example 1" /></a></p>
<ul>
<li><a href="https://www.reddit.com/r/chess/comments/40c4ld/problem_white_to_play_8_consecutive_moves_from/" rel="nofollow noreferrer">Example 2</a></li>
</ul>
<p><strong>EDIT</strong></p>
<ul>
<li><p>Thanks @ETD for pointing out that it's possible to create programs to solve, at least by brute force solutions to any chess problems. What I mean though is normal chess computers.</p>
</li>
<li><p>EDIT 2: I realize that the question is a bit vague. What I really like to know is creative puzzles, which if given to a beginner player should not be solvable by putting it on his computer and running an analysis.</p>
</li>
</ul>
 11629: <p>Apart from non-standard problems (fairy chess, retrograde analysis, etc), there also exist particularly difficult regular chess problems which are used for testing chess engines, like Nightmare II. These might not be solvable by some engines/computers. Take a look at <a href="https://chessprogramming.wikispaces.com/Test-Positions" rel="nofollow noreferrer">this list</a> </p>
 8860: <p>Try also Burt Hochberg's <strong>Chess Braintwisters</strong>,
which often require "thinking outside the box" to a move that is
logical but illegal (like promoting to a King) and thus would never
be found by an ordinary chess-playing or problem-solving computer program.
A couple of examples from that book have already been posted in this forum
in reply to another question: <a href="https://chess.stackexchange.com/questions/13322/is-there-any-position-where-not-promotingillegally-would-be-the-best-move">Is there any position where not promoting(illegally) would be the best move?</a></p>
 3819: <p>There is a branch of Problem Chess called <strong><a href="https://en.wikipedia.org/wiki/Fairy_chess" rel="nofollow noreferrer">Fairy Chess Problems</a></strong> with all kinds of stipulations.</p>

<p>However, there are specialised programs (e.g. Alybadix or Chloe/WinChloe) to solve fairy chess problems and nowadays problem composers routinely use them to verify the integrity of their creations. For more information, look at <a href="https://en.wikipedia.org/wiki/Software_for_handling_chess_problems" rel="nofollow noreferrer">https://en.wikipedia.org/wiki/Software_for_handling_chess_problems</a></p>
 1485: <p>Here is a fun puzzle:</p>

<p>Construct a legal chess game where</p>

<ul>
<li>white starts with <code>1. a3</code>,</li>
<li>white delivers checkmate on move 5, and</li>
<li>the last move is made with the rook that started on <code>a1</code>.</li>
</ul>

<blockquote class="spoiler">
  <p> Hint: Black takes the pawn on <code>a3</code>.</p>
</blockquote>
 9030: <p><a href="http://www.theproblemist.org/what-are-chess-problems" rel="noreferrer">This</a> is an excellent source for problems from different range of difficulty, where you can find these types of problems:</p>

<ul>
<li>Selfmate</li>
<li>Helpmate</li>
<li>Reflexmate</li>
<li>Retrograde Analysis</li>
</ul>

<p>Which regular chess engines can't solve because solutions are not the best moves. (Actually, worst moves in selfmate problems for example)</p>
 15989: <p>I will do the obligatory retro and proof game plug:</p>
<h2>Proof games</h2>
<p>A type of problem where you are to reach the diagram position within a given number of moves.</p>
<p>A <a href="http://abrobecker.free.fr/chess/IntroductionToPGs.pdf" rel="nofollow noreferrer">good introductory PDF by Alain Brobecker</a>, featuring many &quot;classic&quot; problems that are well-known among the proof game community.</p>
<p>Jeff Coakley has a lot of shorter (but still tricky) 4-move proof games on <a href="https://chesscafe.com/columns/the-puzzling-side-of-chess/" rel="nofollow noreferrer">chesscafe</a> (although the site put them behind a paywall since 2014, the resourceful reader can probably figure something out...)</p>
<p>Another simple example (original by me): Reach the position after black's 4th move.</p>
<pre><code>rnbqkbnr/1ppppppp/8/p7/3P4/8/PPP1PPPP/RNB1KBNR w - - 0 1
</code></pre>
<p>Shorter proof games of about 4 to 7 moves are pretty good for regular chess players, and you literally only need to know how the pieces move. Longer ones can go up to 30 moves (for a &quot;normal&quot; long proof game) or even over 180 moves (the longest I know of).</p>
<h2>Retrograde analysis</h2>
<p>Given only the diagram position and the fact that it was reached in a legal chess game, determine some feature of the position like side to move, castling rights, en passant rights, whether a piece is promoted...</p>
<p>An excellent <a href="https://www.janko.at/Retros/PedagogicalCollection.htm" rel="nofollow noreferrer">collection of simpler problems</a> that slowly rise in difficulty.</p>
<p>A magnificent <a href="https://www.chessproblem.net/viewtopic.php?t=429" rel="nofollow noreferrer">introductory text</a> by Nikolai Beluhov, an excellent composer of such problems. (Link is to a post containing PDF attachment.)</p>
<p>Another easy example by me again (although the idea is not new): What was the last move played? (I don't even need to give you the side to move for you to solve it.)</p>
<pre><code>8/8/8/8/8/4PP2/1PPPRKPk/4nQ2 w - - 0 1
</code></pre>
