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 '17 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 '17 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 '17 at 6:36
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    $\begingroup$ This is not a unique puzzle! $\endgroup$ – The Great Duck May 27 '17 at 1:54
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    $\begingroup$ @RosieF thanks for the source, I added it! $\endgroup$ – Quintec May 28 '17 at 0:36

I've found the actual answer:

1. Rc6


1... Rxh7


The rook isn't pinned any more


Unforced checkmate

  • $\begingroup$ Nice puzzle, by the way. Had me fooled for a bit. $\endgroup$ – boboquack May 26 '17 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 $\endgroup$ – Vitruvius May 27 '17 at 0:36

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 '17 at 0:07
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    $\begingroup$ The puzzle explicitly asks for a legal move. Resignation isn't a move. $\endgroup$ – David Richerby May 26 '17 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 '17 at 14:22

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 '17 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 '17 at 14:24

protected by Beastly Gerbil May 27 '17 at 11:52

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