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Find a legal move for white that does NOT mate in one. White to move

Source: by Karl Fabel & was reprinted in Martin Gardner's New Mathematical Diversions from Scientific American (pub. Simon & Schuster), ch.19, p.223

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    $\begingroup$ I like to accept >12-18 hours after posting, because then you get attention to your puzzle but don't forget about the accepting altogether $\endgroup$
    – boboquack
    May 26, 2017 at 0:15
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    $\begingroup$ It would be nice to add the proper reference for this puzzle, which was invented by puzzle master Sam Loyd. $\endgroup$
    – Yrodro
    May 26, 2017 at 4:46
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    $\begingroup$ @Yrodro It would indeed be nice to add the proper reference. I regret that I don't have it (the problem appears to not be in PDB or YACPDB), but I can say that it's by Karl Fabel & was reprinted in Martin Gardner's New Mathematical Diversions from Scientific American (pub. Simon & Schuster), ch.19, p.223. $\endgroup$
    – Rosie F
    May 26, 2017 at 6:36
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    $\begingroup$ This is not a unique puzzle! $\endgroup$
    – user64742
    May 27, 2017 at 1:54
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    $\begingroup$ @RosieF thanks for the source, I added it! $\endgroup$
    – Quintec
    May 28, 2017 at 0:36

3 Answers 3

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I've found the actual answer:

1. Rc6

Then:

1... Rxh7

Because:

The rook isn't pinned any more

Picture:

Unforced checkmate

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  • $\begingroup$ Nice puzzle, by the way. Had me fooled for a bit. $\endgroup$
    – boboquack
    May 26, 2017 at 0:08
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    $\begingroup$ You could extend this puzzle to "White to play and stalemate", with 2. Rxc5+ Rb7 3. Kf8 1/2-1/2 $\endgroup$
    – Vitruvie
    May 27, 2017 at 0:36
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Another commonly seen solution to this sort of problem:

White can legally resign.

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    $\begingroup$ also not the intended answer, but true, i guess :) I think they need to make a meta post about chess loopholes now! xD $\endgroup$
    – Quintec
    May 26, 2017 at 0:07
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    $\begingroup$ The puzzle explicitly asks for a legal move. Resignation isn't a move. $\endgroup$ May 26, 2017 at 19:20
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    $\begingroup$ There's an unwritten convention that players can't resign or agree a draw. That would just break so many problems. If you have commonly seen it, then please show me an example: I would really appreciate it. $\endgroup$
    – Laska
    Nov 3, 2017 at 14:22
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I suspect the trick is, as with so many chess puzzles, that:

we are looking at the board the wrong way.

In this case, there are several possible moves:

Actually, I think there's no move that can force mate, if this is the case, because now the pawns are 'blocking' the wrong squares.

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    $\begingroup$ nice try, but this is not the case for this puzzle. the rank on the bottom is indeed the first rank. $\endgroup$
    – Quintec
    May 25, 2017 at 23:59
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    $\begingroup$ It's true that sometimes the board is upside down. That is probably the most common unofficial joke. But you need to exhaust other options first. (The official joke, enshrined in the legendary Codex of Chess Problem Conventions, is that it may be the unexpected side to move, if you can prove that the expected side couldn't have moved last.) $\endgroup$
    – Laska
    Nov 3, 2017 at 14:24

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