A Chess paradox

Discuss anything you like about chess related matters in this forum.
Alex McFarlane
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Re: A Chess paradox

Post by Alex McFarlane » Tue Nov 29, 2011 10:19 am

Black king on e8 Black rook on f7
White Qh5, Be4, Re2 Kh1 and pawns on g2 and h2.

White plays Bc6 with double check. Black replies Rf1 mate!

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Christopher Kreuzer
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Re: A Chess paradox

Post by Christopher Kreuzer » Tue Nov 29, 2011 11:04 am

Alex McFarlane wrote:Black king on e8 Black rook on f7
White Qh5, Be4, Re2 Kh1 and pawns on g2 and h2.

White plays Bc6 with double check. Black replies Rf1 mate!
That's ridiculous. The triple check only happens after Black moves the rook. It is only a double-check when it is Black's turn to move. Unless I'm imagining the position wrong. I'm positive there is a way to get a triple check after White's move and before Black replies. Probably involving en passant and/or promotion, but maybe not if your example (moving a pinned piece) is the only (silly) way to get a triple check on the board.

Geoff Chandler
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Re: A Chess paradox

Post by Geoff Chandler » Tue Nov 29, 2011 11:06 am

Dear Justin and Alex.

Next time you see Carl look at the wrinkles on his forehead.
I put them there with my constant pleading for a diagram thingy
and pgn moving thingy thing.

Eventually it happened. Please use the fen thingy thing.

This is something like the position Justin mentioned.



Black plays 1...b1=White Knight mate.

And Alex's position.



1.Bc6++ Rf1 mate.

Carl had to go to night classes to learn how to do this.
The least we can do is to use this fen thingy every chance we get.

Thank You

A Lucky Escape in the Rules.

When the original rules were being laid down some bright spark might have
added that when a player is left with a lone King he can 'pass' and give the
move back to his opponent.



If so then it would impossible to deliver mate in a King & Rook v King ending.
From the above position.

1.Rc2 pass
2.Rc3 pass
3.Rc1 pass
4.Rh1 Kc8

Jon D'Souza-Eva

Re: A Chess paradox

Post by Jon D'Souza-Eva » Tue Nov 29, 2011 11:51 am

How about the Dummy Pawn rule? Not a misreading of a rule, just a very strange one to include in the first place.

Here is Sam Loyd's puzzle which takes advantage of this.


White to move and mate in 3.

Solution: 1. cxd8=P

Kevin Thurlow
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Re: A Chess paradox

Post by Kevin Thurlow » Tue Nov 29, 2011 12:12 pm

It was something like:-

White - Kd4, Ne5
Black - Kh8, Rg8 and d1, Nd2, Bf6, Pawns g7 and h7

1.Nf3++ Nf7 Mate!! as the white king was now attacked by three pieces, and therefore not in check.

I didn't manage to find an arbiter who would have allowed that, even after I showed them the laws...
"Kevin was the arbiter and was very patient. " Nick Grey

Stewart Reuben
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Re: A Chess paradox

Post by Stewart Reuben » Tue Nov 29, 2011 12:56 pm

I had forgotten another mistake in the Laws. It was about castling.
This used to be defined as the king being transferred from its original square two moves towards the rook on its original square... Thus you could castle with a rook that had been promoted by e7-e8=R. The spoil sports have added in along the player's first rank.

Christopher > Unless I'm imagining the position wrong. I'm positive there is a way to get a triple check after White's move and before Black replies.<
Odd that. I am even more positive that it is impossible to create a triple check, except by starting with a double check and that quadruple checks are even more impossible.

Geoff. Have you only just realised that chess would be a completely different game without the compulsion to move?

A paradox that is known about and we don't know how to cover it in the Laws.
This is in blitz 1 e4 e5 2 Nf3 Nc6 3 Bc4 Nf6 4 Q Nd4 back to White 4 Qh5 (illegal) and 5 Qxf7 mate (legal). White touched his queen on move 4 and black played Nd4 before his hand had quite the queen. White's clock is still going. So he doesn't play Qe2, th only legal move, but plays Qh5 instead.

1 e4 d6 2 Bb5ch f5 3 Qh5 mate. Somebody tried to convince me recently this had actually happened. But perhaps I am just being cynical and it really has.

It could be solved by requiring all previous moves to be legal to be able to give checkmate. That would mean checking every game prior to accepting a checkmate.

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