[Retros] FW: FW: Distance-PG

[Yoav Ben-Zvi]

Verification must wait for a full search of all sound SPGs in 6.0. Meanwhile
humans can play a race with the computer by finding better candidates such
as:

Natch 3.0.beta      Copyright (C) 1997,98,99,2001-2005,2016 Pascal Wassong

+---+---+---+---+---+---+---+---+
|   |*S |   | . |*K | . |*S |*R |
+---+---+---+---+---+---+---+---+
|*P |   | . |*P | . |*P |*P |*P |
+---+---+---+---+---+---+---+---+
|   | . |   | . |   | . |   | . |
+---+---+---+---+---+---+---+---+
| . |   |*P |   |*P |   | . |   |
+---+---+---+---+---+---+---+---+
|   | . |   | . |   | P | P |*Q |
+---+---+---+---+---+---+---+---+
|*B |   | . |   | . | B | . |   |
+---+---+---+---+---+---+---+---+
| P | P | P | P | P | . |*B | P |
+---+---+---+---+---+---+---+---+
| R | S | B | Q | K |   | S | R |
+---+---+---+---+---+---+---+---+
1s2k1sr/p2p1ppp/8/2p1p3/5PPq/b4B2/PPPPP1bP/RSBQK1SR
12 single moves.	16 + 14

The resolution begins at Wed Aug 31 10:55:55 2016

Solution 1 (position 1)
1.Pg2-g4   Pe7-e5   2.Bf1-g2   Bf8-a3   3.Bg2xb7   Pc7-c5   
4.Bb7xa8   Bc8-b7   5.Pf2-f4   Bb7-g2   6.Ba8-f3   Qd8-h4   

The resolution ends at Wed Aug 31 10:55:55 2016
Solution found: 1
Position analysed: 1
Resolution time: 0.08 s. 

This has length of  8+27*SQRT2 = 46.18  which beats 19+10*SQRT2+4*SQRT5 =
42.09

Yoav

-----Original Message-----
From: Retros [mailto:retros-bounces at janko.at] On Behalf Of Eric Angelini
Sent: Wednesday, August 31, 2016 12:33 AM
To: The Retrograde Analysis Mailing List
Subject: Re: [Retros] FW: Distance-PG


Hello Yoav,
clever modification!
But I'm unable to confirm that this is the unique
>Sound SPG in 6.0 ending in checkmate with maximum
geometric length<
... unfortunately, as Ihave absolutely no idea to check that...
Best,
É.



________________________________________
De : Retros [retros-bounces at janko.at] de la part de Yoav Ben-Zvi
[yoavbz97 at gmail.com] Date d'envoi : mardi 30 août 2016 22:00 À : Retro List
Objet : [Retros] FW:  Distance-PG

A minor modification of Olli's SPG:

Natch 3.0.beta      Copyright (C) 1997,98,99,2001-2005,2016 Pascal Wassong

+---+---+---+---+---+---+---+---+
|*R |*S |   | . |*K |*B |   |*R |
+---+---+---+---+---+---+---+---+
|*P |*P |*P |   |*P |*P |*P |*P |
+---+---+---+---+---+---+---+---+
|   | . |   | . |   | . |   | B |
+---+---+---+---+---+---+---+---+
| . |   | . |   | . |   | . |   |
+---+---+---+---+---+---+---+---+
|   | . |   | . |   | . |   | . |
+---+---+---+---+---+---+---+---+
| . |   |*S |   | . |   | . |*B |
+---+---+---+---+---+---+---+---+
| P | P | P | . | P | P | P | P |
+---+---+---+---+---+---+---+---+
| . |   | . |*Q | K | B | S | R |
+---+---+---+---+---+---+---+---+
rs2kb1r/ppp1pppp/7B/8/8/2s4b/PPP1PPPP/3qKBSR
12 single moves.        12 + 15

The resolution begins at Tue Aug 30 22:18:29 2016

Solution 1 (position 2)
1.Pd2-d4   Sg8-f6   2.Pd4-d5   Sf6xd5   3.Sb1-c3   Sd5xc3
4.Qd1xd7   Bc8xd7   5.Bc1-h6   Bd7-h3   6.Ra1-d1   Qd8xd1

The resolution ends at Tue Aug 30 22:18:30 2016 Solution found: 1 Positions
analysed: 2 Resolution time: 0.05 s.

Solves for length  19,10*SQR2,4*SQR5
Is this a solution to: Sound SPG in 6.0 ending in checkmate with maximum
geometric length. If so could it be unique?

-----Original Message-----
From: Retros [mailto:retros-bounces at janko.at] On Behalf Of Olli Heimo
Sent: Tuesday, August 30, 2016 4:17 PM
To: The Retrograde Analysis Mailing List
Subject: Re: [Retros] Distance-PG

Hi! Here is a sound 6-mover!
r1b1kb1r/ppp1pppp/5n2/8/7P/2n4R/PPP1PPP1/R1BqKBN1
        12
 1. Pd2-d4   Cg8-f6     2. Pd4-d5   Cf6xd5     3. Cb1-c3   Cd5xc3
 4. Dd1xd7   Cb8xd7     5. Ph2-h4   Cd7-f6     6. Th1-h3   Dd8-d1

Solution unique 0.45 secondes
Olli.

Eric Angelini kirjoitti 29.08.2016 kello 08:08:
> Ah yes, I see Noam, thanks.
> And again, kudo to Olli!
> Might we "save" the 6.0 solution
> asking this, for instance:
>
> "Find the last move of the fastest
> 20+6SQR5 game ending in checkmate"
>
> If yes, I guess this would be a
> nightmare to solve! (could actual
> softwares like Popeye or Natch
> so that?)
>
> Best,
> É.
>
>
> > Le 29 août 2016 à 01:53, Noam Elkies <elkies at math.harvard.edu> a écrit :
> >
> >
> > Alas it is not unique because White can play Ng3-h3 also on move 4 or 5.
> > Olli Heimo's construction avoided that by replacing Rd7xc7 by Rd7xe7 
> > (which happens to be check, but this was not needed).
> >
> > NDE
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