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MatPlus.Net Forum Internet and Computing Another popeye mystery

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QUOTE

7) Per Olin, Suomen Tehtavaniekat 1/1993

A) 8/PPP2P2/8/8/8/p3pkp1/1T4p1/T3K3
B) B1S2T1D/8/8/8/8/8/6k1/s1K2btd

Stipulation: Shortest proof game from A to B with either white or black to begin

Popeye finds many cooks.

E.g. with Black at the move:
1.a3-a2 0-0-0 2.e3-e2 Rd1-f1 + 3.e2*f1=B b7-b8=Q 4.g2-g1=R Rb2-h2 5.g3*h2 Qb8-h8 6.Kf3-g2 c7-c8=S 7.h2-h1=Q f7-f8=R 8.a2-a1=S a7-a8=B a=>b

And with White at the move:
1.b7-b8=Q a3-a2 2.0-0-0 a2-a1=S 3.Qb8-h8 g2-g1=R 4.c7-c8=S e3-e2 5.Rd1-f1 +
e2*f1=B 6.Rb2-h2 g3*h2 7.f7-f8=R + Kf3-g2 8.a7-a8=B + h2-h1=Q a=>b

QUOTE

And with White at the move:
1.b7-b8=Q a3-a2 2.0-0-0 a2-a1=S 3.Qb8-h8 g2-g1=R 4.c7-c8=S e3-e2 5.Rd1-f1 +
e2*f1=B 6.Rb2-h2 g3*h2 7.f7-f8=R + Kf3-g2 8.a7-a8=B + h2-h1=Q a=>b

Looks like a bug: black's last move is illegal.

I've created a bugreport on SF.

QUOTE
I've created a bugreport on SF.

Thanks. The bug was introduced since 4.47; fixed.

QUOTE
The try where white starts by castling 1.000 ? fails due to the impossibility of the last moves by black.

Now, Popeye doesn't find a solution with White at the move; obviously not for retroanalytical reasons, but because the black king is in check in the final position.

(24) Posted by Per Olin [Thursday, May 19, 2011 22:09]

Glancing at the award in another thread (The ChessProblems.ca 2010 Series Tourney Award posted at http://originals.chessproblems.ca.) we notice that a to b-problems are winning ground. The stipulation seems to suit well for seriesmovers. This reminds me of my first a to b-problem, which is in this thread. It has been cooked, so its only merit seems to be that it has helped to detect a bug in Popeye. Aided by the same program, I have now been able to correct it.

Per Olin
Suomen Tehtäväniekat 1/1993
Correction MatPlusForum 2011

A) 8/P3PP2/1p6/3P4/8/p4kp1/3P2p1/R3K2B

B) B3NR1Q/8/8/8/8/8/6k1/nK1b2rq

Stipulation: Shortest proofgame from A to B with either white or black to begin

1.a3-a2 0-0-0 2.a2-a1=S Kc1-b1 3.b6-b5 Td1-c1 4.b5-b4 Tc1-c3 + 5.b4*c3 d5-d6 6.c3*d2 d6-d7 7.d2-d1=L d7-d8=D 8.g2*h1=D Dd8-h8 9.g3-g2 e7-e8=S 10.g2-g1=T f7-f8=T + 11.Kf3-g2 a7-a8=L+ a=>b The try where white starts by castling 1.000? fails due to the impossibility of the last moves.

The solution is certainly most simple; the idea was to show a new (?) stipulation. In Andernach 2001, mentioned in this thread, the theme tourney was proofgames a to b. The winner by Michel Caillaud (in PDB as nr P1001352) shows double AUW, where the promoted pieces have been captured. This splendid achievement and the problems of the Canadian award should encourage to more composing with a to b!

@Per: Just wanted to post your "A" and "B" diagrams, and a link to Michel's problem, for the benefit of others who read your post:

Per Olin, ST 1993 (MPF 2011 correction)
A:
(= 8+5 )

B:
(= 5+5 )

Shortest proofgame from A to B with either white or black to begin

Solution hidden below:
1.a3-a2 0-0-0 2.a2-a1=S Kc1-b1 3.b6-b5 Td1-c1 4.b5-b4 Tc1-c3 + 5.b4*c3 d5-d6 6.c3*d2 d6-d7 7.d2-d1=L d7-d8=D 8.g2*h1=D Dd8-h8 9.g3-g2 e7-e8=S 10.g2-g1=T f7-f8=T + 11.Kf3-g2 a7-a8=L+ a=>b
The try where white starts by castling 1.000? fails due to the impossibility of the last moves.

Michel's PBD item: http://www.softdecc.com/pdb/search.pdb?expression=PROBID='P1001352'.

EDIT: For whatever reason, I cannot get the link above to work! Frustrating...

I, too, was surprised at how well the a=>b entries fared (top honors in both sections), but they were absolutely deserving.

http://www.softdecc.com/pdb/search.pdb?expression=PROBID=%27P1001352%27

(my RegExp command strips off the last apostrophe - until I fix it you'd better use its URL encoded value: %27)

Thanks Milan!