From joost at sanguis.xs4all.nl Mon Jul 6 10:40:07 2009 From: joost at sanguis.xs4all.nl (Joost de Heer) Date: Mon, 06 Jul 2009 16:40:07 +0200 Subject: [Retros] StrateGems 47, Jul-Oct 2009 Message-ID: <4A520CC7.202@sanguis.xs4all.nl> R0153 - Wolfgang Dittmann 6kS/5S2/8/p5p1/3p4/1pp2p2/b3P2b/3Ks3 (4+10) -15 & #1 Proca, Anticirce P0250 - Ivan Antonov rsb1k1sr/pppp1ppp/8/q1K5/3P4/8/PPP1P1PP/RSBQ1B1R (14+14) PG 8.0 Monochromatic (C+) P0251 - Paul Monski 2sq3r/3ppp1p/2p5/1k6/8/8/1PPPPPP1/RSBQKBSR (14+9) PG 11.5 (C+) P0252 - Kevin Begley, Kostas Prentos pppppppp/rb1kq3/s7/7s/3b4/2r5/PPPPPPPP/RSBQKBSR (16+16) PG 18.0 Equipollentscirce P0253 - James Soliman rsb2bsr/pp1ppppp/2p5/B6Q/2P1P1BR/1PSPRP1K/1P4PP/5kS1 (16+15) PG 20.0 (C+) P0254 - Kostas Prentos 1k1r2r1/4pp1p/2spBs1p/q2p1b2/5b2/8/PpPPPP1P/RSBQK1SR (14+15) PG 20.5 (C+) SOLUTIONS SG45 R0140v - McCracken Add wKe4 wPa2 wPc2 wPe2 wPg2 bKf6 bPb7 bPd7 Only possible retromoves were -1. Kd4xBe4 Bd3(x-)e4. But Bd3 is impossible due to the white and black pawns. Removing a piece results in an easier to resolve check (or no check at all), removing a pawn legalises the bishop. P0236 - Soliman 1. e4 g6 2. Ba6 b5 3. c4 Bb7 4. Nc3 Bxe4 5. Bc8 Bd3 6. Ne4 Bf1 7. d3 Bg7 8. Bh6 Bxb2 9. Bf8 Bc1 P0237 - Grushko 1. d4 g6 2. d5 Bg7 3. d6 Bb2 4. de7 Bd4 5. ed8=R[wBc8,wPd7] Ke7 6. Re8[bBc8,wBf8] Kd6 7. d8=R[wBc8,bRe8] Kc6 8. Rd5 Sd7 9. Ra5 Bc3[bRa1,bRa5,wRh8] 10. Qd2 P0238 - Grudzinski 1. Sc3 e6 2. Sd5 Ba3 3. bxa3-f8=B Qg5 4. Be7 Sxe7-a3 5. Bxa3-b1 Qe3 6. dxe3-c5 exd5-e7 7. Qxd7-d6 Bh3 8. gxh3-c8=B OO 9. Bd7 Sxd7-h3 10. Sf3 cxd6-d7 11. Bxh3-g1 P0239 - Soliman 1. b3 a5 2. Ba3 Ra6 3. Qc1 Rg6 4. Qb2 b6 5. Qxg7 e5 6. Bc1 Qf6 7. Na3 Qf3 8. gxf3 Bc5 9. Bh3 Ke7 10. Qf8+ Kf6 11. Kf1 Kg5 12. Kg2 Ba6 13. Kg3 Bc4 14. Bf1 Na6 15. Qb8 Kh6+ 16. Kh4 P0240 - Sawyer, McCracken 1. a4 g6 2. Ra3 Bg7 3. Rb3 Bc3 4. Rxb7 Nf6 5. Rxa7 Bb7 6. a5 Bf3 7. exf3 Nc6 8. Ke2 Qb8 9. Ke3 Kd8 10. Kf4 Kc8 11. Kg5 Nd8 12. Kh6 g5 13. Kg7 Ng8+ 14. Kf8 Bg7+ 15. Ke8 Bf8 16. Nc3 Nf6# P0241 - Soliman 1. h4 a5 2. Rh3 a4 3. Rb3 axb3 4. axb3 e5 5. Rxa8 Ba3 6. e4 Qe7 7. Ba6 Qc5 8. Qe2 d6 9. Qc4 Bd7 10. d3 Ba4 11. Bd2 Kd7 12. Ba5 Nc6 13. Rxg8 Nd8 14. Rxg7 Rg8 15. Rxh7 Rg3 16. Rh8 Rh3 17. g3 Rh1 P0242 - Donati 1. f4 Na6 2. f5 Rb8 3. f6 gxf6 4. a4 Bh6 5. Ra3 Bf4 6. Rf3 Be5 7. Rf5 Bc3 8. dxc3 Nh6 9. Be3 O-O 10. Bxa7 b6 11. Nf3 Bb7 12. Ne5 Bf3 13. Qd4 Bg4 14. Qg1 Bh3 15. gxh3+ Kh8 16. Bg2 Ng8 17. Ba8 Rxa8 18. Nc6 Nb8 P0243 - Faybish 1. a4 Nc6 2. a5 Ne5 3. a6 bxa6 4. b4 Bb7 5. b5 Qb8 6. b6 axb6 7. c4 Qa7 8. c5 O-O-O 9. c6 dxc6 10. h4 Rxd2 11. Rh3 Rd7 12. Qd6 cxd6 13. Rg3 Kc7 14. Rg6 hxg6 15. g3 Rh5 16. Bh6 gxh6 17. Bh3 Bg7 18. Be6 fxe6 19. f4 Nf7 20. f5 Nh8 21. f6 exf6 From joost at sanguis.xs4all.nl Mon Jul 6 14:36:57 2009 From: joost at sanguis.xs4all.nl (Joost de Heer) Date: Mon, 06 Jul 2009 20:36:57 +0200 Subject: [Retros] StrateGems 47, Jul-Oct 2009 In-Reply-To: <4A520CC7.202@sanguis.xs4all.nl> References: <4A520CC7.202@sanguis.xs4all.nl> Message-ID: <4A524449.6000805@sanguis.xs4all.nl> > P0251 - Paul Monski This should be 'Paul Monsky'. Joost From pascal.wassong at free.fr Wed Jul 8 07:59:41 2009 From: pascal.wassong at free.fr (Pascal Wassong) Date: Wed, 08 Jul 2009 13:59:41 +0200 Subject: [Retros] Natch-2.5Beta Message-ID: <87zlbf4c7m.fsf@free.fr> Hello, after all those years, a bug has been found in Natch by Roberto Osorio. For example, Natch 2.4 doesn't solve the following problem : rs1q1bsr/1ppkpppp/4p3/1K1b4/p7/8/PPPP1PPP/RSBQ1BSR 14 single moves. 15 + 16 The problem is caused by the moves Bc8-d7-c6-d5, necessary because of Pd7xe6, colliding with the move Ke8-d7. If you play 7.Qd7 (or 7.Nd7) instead of 7.Kd7, there is no problem. The problem also disappears if the bK plays another move after passing by d7. By adding 8.Bc4 Kd6, Natch finds again the solution. The complete and technical explanation of this bug is a bit longer. The corrected version Natch-2.5Beta is available in the Beta section of the Natch page, at http://Natch.free.fr/Natch.html If there is no other problem signaled in the next few weeks for this version, it will become the official Natch-2.5 release. By the way, the compiled version for Windows should also work on Vista. Thank you, Roberto, for finding this problem. Pascal From mri_two at t-online.de Thu Jul 9 06:35:43 2009 From: mri_two at t-online.de (Mario Richter) Date: Thu, 9 Jul 2009 12:35:43 +0200 Subject: [Retros] Natch-2.5Beta References: <87zlbf4c7m.fsf@free.fr> Message-ID: <0aa801ca0081$039db9d0$0100a8c0@he2p306> Hello Pascal, > rs1q1bsr/1ppkpppp/4p3/1K1b4/p7/8/PPPP1PPP/RSBQ1BSR > 14 single moves. 15 + 16 > > The problem is caused by the moves Bc8-d7-c6-d5, necessary because of > Pd7xe6, colliding with the move Ke8-d7. > > If you play 7.Qd7 (or 7.Nd7) instead of 7.Kd7, there is no problem. > The problem also disappears if the bK plays another move after passing > by d7. By adding 8.Bc4 Kd6, Natch finds again the solution. Interestingly, if you raise the ply count to 16: Natch 2.4 Copyright (C) 1997,98,99,2001-2005 Pascal Wassong rs1q1bsr/1ppkpppp/4p3/1K1b4/p7/8/PPPP1PPP/RSBQ1BSR 16 single moves. 15 + 16 the first solution given by Natch 2.4 is: Solution 1 (position 1) 1.Pe2-e3 Pa7-a6 2.Pe3-e4 Pa6-a5 3.Pe4-e5 Pa5-a4 4.Pe5-e6 Pd7xe6 5.Ke1-e2 Bc8-d7 6.Ke2-d3 Bd7-c6 7.Kd3-c4 Bc6-d5 8.Kc4-b5 Ke8-d7 > The complete and technical explanation of this bug is a bit longer. so I'm just wondering, if divisibilty by 4 or something similiar did play a role ... Best, mario From joost at sanguis.xs4all.nl Fri Jul 17 06:53:40 2009 From: joost at sanguis.xs4all.nl (Joost de Heer) Date: Fri, 17 Jul 2009 12:53:40 +0200 Subject: [Retros] The Problemist July 2009 Message-ID: <4A605834.5080904@sanguis.xs4all.nl> R411 - Dragan Stojni? r3k1Sr/1p1p1s1S/5R2/7Q/pp1R1p2/P2PpPP1/P1PP1pP1/1Kb5 (14+12) +---+---+---+---+---+---+---+---+ |*R | . | | . |*K | . | S |*R | +---+---+---+---+---+---+---+---+ | . |*P | . |*P | . |*S | . | S | +---+---+---+---+---+---+---+---+ | | . | | . | | R | | . | +---+---+---+---+---+---+---+---+ | . | | . | | . | | . | Q | +---+---+---+---+---+---+---+---+ |*P |*P | | R | |*P | | . | +---+---+---+---+---+---+---+---+ | P | | . | P |*P | P | P | | +---+---+---+---+---+---+---+---+ | P | . | P | P | |*P | P | . | +---+---+---+---+---+---+---+---+ | . | K |*B | | . | | . | | +---+---+---+---+---+---+---+---+ #2 R412 - Alain Brobecker After L.Ceriani R4skR/1p1ppppp/7p/8/S2P3K/7p/P1PPPP1P/8 (11+10) ---+---+---+---+---+---+---+--- R | . | | . | |*S |*K | R ---+---+---+---+---+---+---+--- . |*P | . |*P |*P |*P |*P |*P ---+---+---+---+---+---+---+--- | . | | . | | . | |*P ---+---+---+---+---+---+---+--- . | | . | | . | | . | ---+---+---+---+---+---+---+--- S | . | | P | | . | | K ---+---+---+---+---+---+---+--- . | | . | | . | | . |*P ---+---+---+---+---+---+---+--- P | . | P | P | P | P | | P ---+---+---+---+---+---+---+--- . | | . | | . | | . | ---+---+---+---+---+---+---+--- The position has been shifted on a vertical cylinder. What's the a-file? R413 - Dragan Petrovi? 8/p7/pp4P1/1PPk1PPQ/BrqSbKPS/1pPRppsR/2pp3b/4B1sr (15+16) +---+---+---+---+---+---+---+---+ | | . | | . | | . | | . | +---+---+---+---+---+---+---+---+ |*P | | . | | . | | . | | +---+---+---+---+---+---+---+---+ |*P |*P | | . | | . | P | . | +---+---+---+---+---+---+---+---+ | . | P | P |*K | . | P | P | Q | +---+---+---+---+---+---+---+---+ | B |*R |*Q | S |*B | K | P | S | +---+---+---+---+---+---+---+---+ | . |*P | P | R |*P |*P |*S | R | +---+---+---+---+---+---+---+---+ | | . |*P |*P | | . | |*B | +---+---+---+---+---+---+---+---+ | . | | . | | B | |*S |*R | +---+---+---+---+---+---+---+---+ Circe, how many moves by Sd4 to untie? (Hints for R413: Begin is -1. Sg2-h4 Sf1*Pg3[-] -2. Sg2-h4 b7-b6 -3. g2-g3 Sg3-f1, and the author's solution needs 267 moves to untie the position). F2728c - Paul Raican rs2k1s1/ppp3p1/3r1p2/3p4/3q1b2/8/PP2PPPP/1SBQKBSR (13+13) +---+---+---+---+---+---+---+---+ |*R |*S | | . |*K | . |*S | . | +---+---+---+---+---+---+---+---+ |*P |*P |*P | | . | |*P | | +---+---+---+---+---+---+---+---+ | | . | |*R | |*P | | . | +---+---+---+---+---+---+---+---+ | . | | . |*P | . | | . | | +---+---+---+---+---+---+---+---+ | | . | |*Q | |*B | | . | +---+---+---+---+---+---+---+---+ | . | | . | | . | | . | | +---+---+---+---+---+---+---+---+ | P | P | | . | P | P | P | P | +---+---+---+---+---+---+---+---+ | . | S | B | Q | K | B | S | R | +---+---+---+---+---+---+---+---+ PG 8.0 (Annan) SOLUTIONS January 2009 R405 - Dunn 1. g4 e5 2. Bh3 Qh4 3. g5 e4 4. Bxd7+ Nxd7 5. Nh3 Ne5 6. O-O Bxh3 7. f4 O-O-O 8. Rf3 Rd6 9. Rd3 Rg6 10. Rd5 Bc5+ 11. d4 exd3+ 12. Be3 d2 13. Bd4 Nd3 14. e3 Ne1 15. Qg4+ f5 16. gxf6+ R406 - Le Gleuher 1. a4 Nc6 2. Ra3 Nd4 3. Rc3 Nb5 4. Rxc7 Na3 5. Rc3 Qa5 6. h4 Qh5 7. Rch3 g5 8. Nf3 Bg7 9. Rg1 Be5 10. Rhh1 Bh2 11. g3 b5 12. Bh3 Bb7 13. Kf1 O-O-O 14. Kg2 Kb8 15. Re1 Rc8 16. Kf1 Rc3 17. Ng1 Rb3 18. cxb3 f5 19. Qc2 Nf6 20. Rd1 Rc8 21. Ke1 Rc3 22. Bf1 Re3 23. Qc4 Be4 24. Nc3 Bc2 25. d3 a5 26. Bd2 Ka7 27. Ra1 Bd1 28. Nb1 From peter.fayers at virgin.net Sun Jul 19 03:53:41 2009 From: peter.fayers at virgin.net (peter.fayers at virgin.net) Date: Sun, 19 Jul 2009 07:53:41 +0000 (GMT) Subject: [Retros] Problemist - Solutions Jan 2009 Message-ID: <1473042311.20156.1247990021237.JavaMail.mail@webmail09> An HTML attachment was scrubbed... URL: