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MatPlus.Net Forum General Because of current events...
 
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(1) Posted by Hauke Reddmann [Friday, Dec 10, 2021 18:11]

Because of current events...


One of our aspiring youth got clobbered when
he tried to copy the opponent's moves,
added insult to injury his first own was
the first patzer. (I didn't mean Carlsen-Nepo :-)
So, assume we have any symmetric position like
the start of the game. Black announces to copy
White's moves. Loyd knew a fast #4, but it is
evident to me there is no s# at all from any
symmetric position. With which fairy condition
White could play on s# if Black copies? (Any
symmetric start position allowed.)
 
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(2) Posted by Michael McDowell [Friday, Dec 10, 2021 18:53]

What's wrong with some position like this:

(= 13+13 )


Easy to reach with symmetrical moves (the h-rooks being promoted pawns)

1.Qa5+ QxQ.
 
 
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(3) Posted by James Malcom (Rewan Demontay) [Friday, Dec 10, 2021 19:53]

I bid 30 pieces!

(= 15+15 )


QxQ+ & KxQ#

1. e3 e6 2. Ke2 Ke7 3. Kf3 Kf6 4. Kg3 Kg6 5. Kh3 Kh6 6. Nf3 Nf6 7. Ne5 Ne4 8. Ng6 Ng3 9. hxg3 hxg6 10. Rh2 Rh7 11. Qg4 Qg5
 
   
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(4) Posted by Dmitri Turevski [Friday, Dec 10, 2021 20:41]

Isn't the challenge so that the last black move should also be symmetrical (thus fairies)?
(= 2+2 )

Masand
1.Qh7+ Qh2(h7=b)#
 
   
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(5) Posted by Nikola Predrag [Friday, Dec 10, 2021 21:47]

Would be if you add wSf8 & bSf1.
 
   
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(6) Posted by Dmitri Turevski [Friday, Dec 10, 2021 22:15]

 QUOTE 
Would be if you add wSf8 & bSf1.

Nope, under "Black-must-copy" condition the checkmate is forced without knights.
 
   
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(7) Posted by Hauke Reddmann [Saturday, Dec 11, 2021 10:01]

Yes, indeed I meant *all* moves are symmetrical,
including the one fulfilling the stipulation.
Concerning Dmitri's offer and the version,
I'd prefer that it is mate NOT just because
of the "I promise to move symmetrical" condition
(after all, Loyd's 1.d4 d5 2.Qd3 Qd6 3.Qh3 Qh6 4.Qc8#
is still mate even if Black now changes mind).
But that is personal taste and I accept it as a
solution (as soon as I looked up "Masand" :-)

Still, Michael and Rewan created a legit challenge:
"Shortest symmetrical play from starting position
to a valid s#1". (Where the # move may be asymmetric.)
 
   
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(8) Posted by Arno Tungler [Sunday, Dec 12, 2021 09:32]

@Michael: The h-rooks can never come to their positions...
@James: Here are all 32 pieces with the same move number. Can you get it with less moves?

(= 16+16 )


PS: For the fun you can also move the h-rooks to the f-file...
 
   
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(9) Posted by Joost de Heer [Sunday, Dec 12, 2021 14:01]

 QUOTE 

@Michael: The h-rooks can never come to their positions...

Promoted rooks (which Michael already mentioned in his post).
 
   
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(10) Posted by Arno Tungler [Sunday, Dec 12, 2021 20:49]

Yes, I overlooked that!
 
   
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(11) Posted by Joost de Heer [Monday, Dec 13, 2021 11:50]

Winchloe has a fairy condition 'Symmetriezüger', unfortunately this is for both mirror and axial symmetry, but with a lot of patience you can probably search through all 20 begin positions after the first moves by both black and white for a s#10.
 
 
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(12) Posted by Arno Tungler [Monday, Dec 13, 2021 11:51]

Similar but also 12 moves…

(= 16+16 )

 
   
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(13) Posted by Arno Tungler [Monday, Dec 13, 2021 12:08]

And finally two moves shorter…

(= 16+16 )

 
   
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(14) Posted by James Malcom (Rewan Demontay) [Monday, Dec 13, 2021 16:01]

Bravo Arno!
 
   
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(15) Posted by Arno Tungler [Tuesday, Dec 14, 2021 14:27]

Samuel Loyd had already 155 years ago even two moves less…!!

(= 16+16 )

S#8
Black is forced to imitate the white moves

Loyd‘s stipulation: “If both parties make the same moves, how can the first player self-mate on the eighth move?”

1. e4 e5 2. Ke2 Ke7 3. Ke3 Ke6 4. Qf3 Qf6 5. Se2 Se7 6. b3 b6 7. Ba3 Ba6 and then 8. Sd4+ exd4#

See https://pdb.dieschwalbe.de/P1298028

Extraordinary!
 
   
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(16) Posted by seetharaman kalyan [Tuesday, Dec 14, 2021 16:16]

Wow! What an extraordinary man Loyd was!
 
   
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(17) Posted by Miodrag Mladenović [Tuesday, Dec 14, 2021 16:26]

Am I missing something or Loyd's position has a cook:

1.e4 e5 2.Qf3 Qf6 3.Ke2 Ke7 4.Ke3 Ke6 etc...

It's pity that solution is not a unique solution.
 
   
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(18) Posted by James Malcom (Rewan Demontay) [Tuesday, Dec 14, 2021 16:38]

Miodrag, by that standard, all of the solutions we have given are "cooked" then. They are not meant to be unique. If you wish to pursue the challenge of the; shortest unique proof game for a mutual selfmate one, go right ahead!
 
 
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(19) Posted by seetharaman kalyan [Tuesday, Dec 14, 2021 20:40]

I am sure Loyd challenged to find the shortest moves.
 
 
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