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MatPlus.Net Forum General is the poor man's reciprocal change....
 
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(1) Posted by Eugene Rosner [Sunday, Dec 25, 2016 19:23]

is the poor man's reciprocal change....


LeGrand, or pseudo LeGrand?!
 
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(2) Posted by Evgeni Bourd [Sunday, Dec 25, 2016 20:30]

Maybe a reciprocal change with only 1 phase?
 
 
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(3) Posted by Miodrag Mladenović [Sunday, Dec 25, 2016 20:41]; edited by Miodrag Mladenović [16-12-25]

My take is that "Le Grand" is real theme with a paradox. The "Pseudo Le Grand" does not contain any paradox and it's trivial theme. It's very often randomly created (something else is the main theme and "Le Grand" is there just by an accident). Personally I do not like any "pseudo" theme. It's always a trivial form of the real theme.
 
   
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(4) Posted by Hauke Reddmann [Monday, Dec 26, 2016 17:58]

Hey, you *can* do a reciprocal change in one phase :-)

(1...x~ 2.A, 1...x?! 2.B, 1...y~ 2.B, 1...y?! 2.A)
 
   
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(5) Posted by seetharaman kalyan [Monday, Dec 26, 2016 18:27]

This pattern is called reciprocal black correction. Without changes the pattern is quite easy. C.G.S.Narayanan did a lot of them -- with changed mates of course. Cyclic black correction is more interesting.
 
   
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(6) Posted by Eugene Rosner [Monday, Dec 26, 2016 21:08]

thanks for the responses everyone. I just remember reading, in some journal, maybe even here!, that one of the two mentioned themes was the poor man's version. Having just completed a LeGrand composition, I was wondering about that far-removed comment, but I'm still curious.I think I agree with Mio in that the LeGrand is a paradoxial theme and not easy to execute sometimes. I agree with his pseudo comment for I easily came up with the pseudo version of my recent problem fairly easily-the LeGrand version was considerably harder. But I got it in the end! :-D
so if I had to guess, PLG is the poor man's version....
 
   
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(7) Posted by shankar ram [Tuesday, Dec 27, 2016 14:33]; edited by shankar ram [16-12-27]

Eugene, I too don't subscribe to the "poor man" epithet.
But I characterise the le grand theme as the "short cut" version of the reciprocal change theme.
That is, instead of 1...a/b 2.A/B & B/A, we have 1.?(2.A) x 2.B & 1.!(2.B) x 2.A
You can also have a "secondary" le grand as: 1..x~ 2.A 1...x! 2 B & 1...x~ 2.B 1...x! 2.A
This is usually called as "reciprocal change after random and correction moves of the same B piece".
This form is also amenable to the "pseudo" treatment: just vary the correction move!
 
   
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(8) Posted by Paz Einat [Tuesday, Dec 27, 2016 21:25]

I too agree with Miodrag's thoughts on "pseudo" especially in connection with le Grand. It's a pseudo theme... Personally, I refrain from using this term because usually it is just some combination of mate transfers.
Regarding Hauke's pattern, this is the Feldman theme, done many times cyclically (up to a 4-move cycle - a famous Retter #2 problem) and lately it was the theme of the Retter 80 JT for selfmates.
 
   
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(9) Posted by shankar ram [Wednesday, Dec 28, 2016 02:07]

Paz,
The record for the Feldmann cycle is 5 points in orthodox two movers ( 2 examples by Parthasarathy).
In fairies, I have an example with 6 points. Maybe composers like Loustau or Aschwanden have taken it further!
 
   
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(10) Posted by Rajendiran Raju [Wednesday, Dec 28, 2016 18:29]; edited by Rajendiran Raju [16-12-29]

PS 2459
Linden Lyons (Australia)
THE PROBLEMIST SUPPLEMENT
JULY 2011
(= 6+5 )

#2

1.Qe2? (2.Qd1) Sf4!
1.Qg1? (2.Qd1) Rf2!
1.Qh1? (2.Qd1) 1…Rf2, Rf1 2.Qxe4 1…e2!

1.Qg4! (2.Qxe4#)
1…Rf4 2.Qd1#
1…Sf4 2.Qg7#
1…Sg5 2.Qd7#
1…Sc5 2.Bc3#

The pseudo le Grand theme (1.Try? (>2.A) 1…x 2.B; 1.Key! (>2.B) 1…y 2.A) differs from the le Grand theme in that the thematic defence is not the same in each phase (MMcD).
 
   
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(11) Posted by seetharaman kalyan [Thursday, Dec 29, 2016 04:57]

You are right Raju. As Misha mentions, When the refutation move is different, there is no paradox or surprise.... so it is perhaps only a pseudo theme!
 
 
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MatPlus.Net Forum General is the poor man's reciprocal change....