[Retros] RE : Brute force for At Home PGs + construction tasks

[Eric Angelini]

Merci bcp, Francois !
Joyeux Noel aussi,
a+
E.


-------- Message d'origine--------
De: retros-bounces at janko.at de la part de François Perruchaud
Date: jeu. 24/12/2009 08:56
À: The Retrograde Analysis Mailing List
Objet : [Retros] Brute force for At Home PGs + construction tasks
 
Eric Angelini a écrit :

> I was wondering, seeing the "at home" examples, if

> brute force has already being used to check all "at

>

> home PG" positions [...]

I analysed my old files (in my old computer) and can now precise my 
previous results :

With 30 pieces : 25 exact PGs (with multiplicity)
4.5 moves : 6
5.0 moves : 2
5.0 and 5.5 moves : 8
7.5 moves : 1 ( 1nbqkbnr/pppppppp/8/8/8/8/PPPP1PPP/RNBQKBNR )

With 29 pieces : 41 exact PGs
4.0 moves : 7
4.5 moves : 8
5.0 moves : 7
5.5 moves : 15
6.0 moves : 3
6.5 moves : 1 ( rnbqkbnr/1ppppppp/8/8/8/8/1PPPP1PP/RNBQKBNR )

With 30 pieces : 276 exact PGs (with multiplicity)
4.0 moves : 3
4.5 moves : 22
4.5 and 5.0 moves : 1
5.0 moves : 36
5.5 moves : 46
5.5 and 6.0 moves : 8
6.0 moves : 67
6.0 and 6.5 moves : 2
6.5 moves : 44
6.5 and 7.0 moves : 2
7.0 moves : 12
7.0 and 7.5 moves : 2
7.5 moves : 10
7.5 and 8.0 moves : 1
8.0 moves : 2
8.5 moves : 1
9.0 moves : 1

I did it in 2005. The starting point was a discussion between François 
Labelle and Mario Richter.
So almost certainly someone else already did the job, but i didn't see 
it in the Retro List. Sorry if i missed it.

Construction tasks :
Compose an exactAt Home PG
- with 30 pieces and 7.5 moves (already known)
- with 29 pieces and 6.5 moves (already known)
- with 28 pieces and 8.5 moves
- with 28 pieces and 9.0 moves (I think i saw it before)

Happy Christmas to all retro fans,
FPC









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