From raosorio at fibertel.com.ar Sat Nov 1 11:06:35 2008 From: raosorio at fibertel.com.ar (raosorio at fibertel.com.ar) Date: Sat, 01 Nov 2008 12:06:35 -0300 Subject: [Retros] PGs of the Future / the PR(Q) mx PR(R) case Message-ID: <463d49c864b7.490c464b@fibertel.com.ar> Hi friends, I found a new very relevant example, PR(Q) mx PR(R) Unto Heinonen / 8424 Die Schwalbe 145 02/1994 2. Preis / H34 FIDE Album 1992-1994 --------------------------------------------------------------------------------------------------------------------------- k2qr1nr/1p3pp1/n1p2p2/bB6/KPP2Nb1/6p1/1PP2PP1/RNRQB3 1. e4 h5 2. Dg4 hxg4 3. Se2 Th3 4. Sf4 Tb3 5. axb3 d5 6. Ta6 d4 7. Tf6 a5 8. h4 a4 9. h5 a3 10. h6 a2 11. h7 a1=T 12. h8=T T1a5 13. Th3 Th5 14. Lb5+ c6 15. d3 Dd5 16. Kd2 Dc4 17. dxc4 d3 18. Kc3 Th8 19. Kb4 Sa6+ 20. Ka4 exf6 21. Ld2 Lb4 22. Tc1 La5 23. Le1 d2 24. b4 d1=D 25. Ta3 g3 26. e5 Lg4 27. e6 0-0-0 28. e7 Kb8 29. e8=D Ka8 30. De2 Te8 31. Ta1 Dd8 32. Dd1 -------------------------------------------------------------------------------------------------------------------------- Best, Roberto From joost at sanguis.xs4all.nl Wed Nov 5 12:03:11 2008 From: joost at sanguis.xs4all.nl (Joost de Heer) Date: Wed, 05 Nov 2008 18:03:11 +0100 Subject: [Retros] Probleemblad 3-2008 (Jul-Sep) Message-ID: <4911D1CF.6000305@sanguis.xs4all.nl> R341 - Jacob Mintz 2k1r1s1/ppp2p2/8/8/3q4/8/PPPPPpPP/RSBQKBSR (15+9) +---+---+---+---+---+---+---+---+ | | . |*K | . |*R | . |*S | . | +---+---+---+---+---+---+---+---+ |*P |*P |*P | | . |*P | . | | +---+---+---+---+---+---+---+---+ | | . | | . | | . | | . | +---+---+---+---+---+---+---+---+ | . | | . | | . | | . | | +---+---+---+---+---+---+---+---+ | | . | |*Q | | . | | . | +---+---+---+---+---+---+---+---+ | . | | . | | . | | . | | +---+---+---+---+---+---+---+---+ | P | P | P | P | P |*P | P | P | +---+---+---+---+---+---+---+---+ | R | S | B | Q | K | B | S | R | +---+---+---+---+---+---+---+---+ SPG 10.0 R342 - Unto Heinonen 2k5/p1p1qpp1/2ss1pB1/6B1/6P1/b1P2Pr1/PPP1P1bP/1SrQK1SR (15+13) +---+---+---+---+---+---+---+---+ | | . |*K | . | | . | | . | +---+---+---+---+---+---+---+---+ |*P | |*P | |*Q |*P |*P | | +---+---+---+---+---+---+---+---+ | | . |*S |*S | |*P | B | . | +---+---+---+---+---+---+---+---+ | . | | . | | . | | B | | +---+---+---+---+---+---+---+---+ | | . | | . | | . | P | . | +---+---+---+---+---+---+---+---+ |*B | | P | | . | P |*R | | +---+---+---+---+---+---+---+---+ | P | P | P | . | P | . |*B | P | +---+---+---+---+---+---+---+---+ | . | S |*R | Q | K | | S | R | +---+---+---+---+---+---+---+---+ SPG 21.5 R343 - Nicolas Dupont Dedicated to Unto Heinonen 1sb5/6p1/qp6/s4pp1/kpp2rp1/b5r1/1Pp2PP1/RSBQKBSR (11+16) +---+---+---+---+---+---+---+---+ | |*S |*B | . | | . | | . | +---+---+---+---+---+---+---+---+ | . | | . | | . | |*P | | +---+---+---+---+---+---+---+---+ |*Q |*P | | . | | . | | . | +---+---+---+---+---+---+---+---+ |*S | | . | | . |*P |*P | | +---+---+---+---+---+---+---+---+ |*K |*P |*P | . | |*R |*P | . | +---+---+---+---+---+---+---+---+ |*B | | . | | . | |*R | | +---+---+---+---+---+---+---+---+ | | P |*P | . | | P | P | . | +---+---+---+---+---+---+---+---+ | R | S | B | Q | K | B | S | R | +---+---+---+---+---+---+---+---+ SPG 28.5 R344 - Paul Raican 8/8/6p1/1k6/4K3/8/6P1/7R (3+2) +---+---+---+---+---+---+---+---+ | | . | | . | | . | | . | +---+---+---+---+---+---+---+---+ | . | | . | | . | | . | | +---+---+---+---+---+---+---+---+ | | . | | . | | . |*P | . | +---+---+---+---+---+---+---+---+ | . |*K | . | | . | | . | | +---+---+---+---+---+---+---+---+ | | . | | . | K | . | | . | +---+---+---+---+---+---+---+---+ | . | | . | | . | | . | | +---+---+---+---+---+---+---+---+ | | . | | . | | . | P | . | +---+---+---+---+---+---+---+---+ | . | | . | | . | | . | R | +---+---+---+---+---+---+---+---+ -10 & s#1, Proca, Anticirce From raosorio at fibertel.com.ar Sun Nov 9 09:46:59 2008 From: raosorio at fibertel.com.ar (raosorio at fibertel.com.ar) Date: Sun, 09 Nov 2008 11:46:59 -0300 Subject: [Retros] PGs of the Future / Phoenix / Tries in PGs Message-ID: <177781b2cbab.4916cdb3@fibertel.com.ar> Hi, I was composing a missed TFPG case (a simple one) and, looking for a quality improvement I realized that an obvious usual trick has to be added to the list: Phoenix, PH(X). There are just 10 PGs in the PDB marked with this keyword, none of them of the future type. Does somebody know any antecedent? It looks quite feasible. Of course the PR(X) is a special case of PH(X) but we are talking here about the cases where the Phoenix piece ends just somewhere on the board. But what I consider the strong point here is that PH(X) provides a very suitable base to enhance a TFPG with an additional content: a thematic try (I got it with that simple case, a TFPG where a PH(X) is a try). I personally do like tries in PGs, respecting the original chess problems? task: to produce paradoxes and to surprise the solutionist. But, what should we consider as to be a try in a PG? Some years ago the judge (Michell Caillaud) gave the first prize to Andrey Frolkin in an orthodox retros? tourney, theme Pronkin / Anti-Pronkin. The diagram shown a very visible Pronkin try but the true solution was based on an Anti-Pronkin. I consider this try as a very nice and subtle content. Jorge Lois and I got the 1sr HM in the Kostas Prentos 40th JT, 1.a4 Na6 2.a5 Nc5 3.a6 c6 4.axb7 Qa5 5.b8=B Ba6 6.Bg3 0-0-0 7.f4 Kb8 8.Kf2 Rc8 9.f5+ Rc7 10.f6 Bb5 11.fxe7 a6 12.e8=B Bd6 13.Bxf7 Ne7 14.Ba2 Qxa2 15.Kf3 Rf8+ 16.Kg4 Rxf1 17.Bf2 Rxf2 Kostas? theme was ?a promoted piece is captured by an officer?; in this PG after 6.Bg3 0-0-0, there is ?at hand? the Gianni Donati 50th?s try 7.Bb8, Kxb8 which would be thematic, but it fails due to a delay in the closing sequence (by the way, this PG shows a double meta-Pronkin performed by bishops, in the sense defined in the article ?There is no place like home?, Osorio & Frolkin, Strategems oct 2007). I remember some ?sex of the angels? discussions in the Argentine Chess Club referring to tries in #2 problems. The point was: should a solving line be considered as a try if you don?t ?try? it? This applies to diagrams where the true solution is more visible than the ?tries?, so as a solutionist you go straight to the solution. I would propose the following requirements for ?tries? in PGs, - A try must be structurally feasible, i.e., the required number of moves and paths must be feasible so it fails just do to sequence reasons. - It has to be ?easy to see? as a solving line; this would be a quality parameter. - The highest quality is reached by a ?thematic try?, i.e., a try thematically connected to the true solution. There are a couple of Lois & Osorio?s pending to appear PGs dealing with this. It would be interesting to discuss other antecedents. Best, Roberto From joost at sanguis.xs4all.nl Thu Nov 13 14:07:48 2008 From: joost at sanguis.xs4all.nl (Joost de Heer) Date: Thu, 13 Nov 2008 20:07:48 +0100 Subject: [Retros] The Problemist, november 2008 Message-ID: <491C7B04.70000@sanguis.xs4all.nl> R403 - Itamar Faybish rs1qkb2/ppp5/3p3Q/4pp1R/6PP/5P2/PPPPPK2/RSB3SB (16+11) +---+---+---+---+---+---+---+---+ |*R |*S | |*Q |*K |*B | | . | +---+---+---+---+---+---+---+---+ |*P |*P |*P | | . | | . | | +---+---+---+---+---+---+---+---+ | | . | |*P | | . | | Q | +---+---+---+---+---+---+---+---+ | . | | . | |*P |*P | . | R | +---+---+---+---+---+---+---+---+ | | . | | . | | . | P | P | +---+---+---+---+---+---+---+---+ | . | | . | | . | P | . | | +---+---+---+---+---+---+---+---+ | P | P | P | P | P | K | | . | +---+---+---+---+---+---+---+---+ | R | S | B | | . | | S | B | +---+---+---+---+---+---+---+---+ PG 13.0 R404 - Unto Heinonen rs2k1sr/ppp1pp1p/8/8/1B6/2S5/PPP2PPP/RSqQKB1R (14+12) +---+---+---+---+---+---+---+---+ |*R |*S | | . |*K | . |*S |*R | +---+---+---+---+---+---+---+---+ |*P |*P |*P | |*P |*P | . |*P | +---+---+---+---+---+---+---+---+ | | . | | . | | . | | . | +---+---+---+---+---+---+---+---+ | . | | . | | . | | . | | +---+---+---+---+---+---+---+---+ | | B | | . | | . | | . | +---+---+---+---+---+---+---+---+ | . | | S | | . | | . | | +---+---+---+---+---+---+---+---+ | P | P | P | . | | P | P | P | +---+---+---+---+---+---+---+---+ | R | S |*Q | Q | K | B | . | R | +---+---+---+---+---+---+---+---+ PG 8.0 (2 solutions) R402c - Nicolas Dupont 1ss2q2/1p1b2p1/1pr1pb2/4k1r1/4p3/3p2p1/1P1PP1p1/RSBQKBSR (11+16) +---+---+---+---+---+---+---+---+ | |*S |*S | . | |*Q | | . | +---+---+---+---+---+---+---+---+ | . |*P | . |*B | . | |*P | | +---+---+---+---+---+---+---+---+ | |*P |*R | . |*P |*B | | . | +---+---+---+---+---+---+---+---+ | . | | . | |*K | |*R | | +---+---+---+---+---+---+---+---+ | | . | | . |*P | . | | . | +---+---+---+---+---+---+---+---+ | . | | . |*P | . | |*P | | +---+---+---+---+---+---+---+---+ | | P | | P | P | . |*P | . | +---+---+---+---+---+---+---+---+ | R | S | B | Q | K | B | S | R | +---+---+---+---+---+---+---+---+ PG 27.5 F2683 - Paul Raican, Vlaicu Crisan 5b2/1k3p1p/8/4r3/1P5K/1p2p3/p1s5/8 (2+9) +---+---+---+---+---+---+---+---+ | | . | | . | |*B | | . | +---+---+---+---+---+---+---+---+ | . |*K | . | | . |*P | . |*P | +---+---+---+---+---+---+---+---+ | | . | | . | | . | | . | +---+---+---+---+---+---+---+---+ | . | | . | |*R | | . | | +---+---+---+---+---+---+---+---+ | | P | | . | | . | | K | +---+---+---+---+---+---+---+---+ | . |*P | . | |*P | | . | | +---+---+---+---+---+---+---+---+ |*P | . |*S | . | | . | | . | +---+---+---+---+---+---+---+---+ | . | | . | | . | | . | | +---+---+---+---+---+---+---+---+ -6 & #1, Proca retractor, Circe Assassin F2684 - Bernd Gr?frath 1sb2b1B/1pkppp1p/rp6/p7/8/P7/P2PP1P1/R2QKBSs (11+13) +---+---+---+---+---+---+---+---+ | |*S |*B | . | |*B | | B | +---+---+---+---+---+---+---+---+ | . |*P |*K |*P |*P |*P | . |*P | +---+---+---+---+---+---+---+---+ |*R |*P | | . | | . | | . | +---+---+---+---+---+---+---+---+ |*P | | . | | . | | . | | +---+---+---+---+---+---+---+---+ | | . | | . | | . | | . | +---+---+---+---+---+---+---+---+ | P | | . | | . | | . | | +---+---+---+---+---+---+---+---+ | P | . | | P | P | . | P | . | +---+---+---+---+---+---+---+---+ | R | | . | Q | K | B | S |*S | +---+---+---+---+---+---+---+---+ PG 12.5 Losing chess From Eric.Angelini at kntv.be Wed Nov 19 11:15:04 2008 From: Eric.Angelini at kntv.be (Eric Angelini) Date: Wed, 19 Nov 2008 17:15:04 +0100 Subject: [Retros] Chess Variants -- 2 moves from one side = one white + 1 black ; then 2 moves from other side = one white + 1 black ; etc. Message-ID: Hello the list, - I've just received this, from Nicolas Graner, a friend of mine. I can translate from the french on request, Best, ?. --- Sais-tu si ces variantes du jeu d'?checs ont d?j? ?t? propos?es ? Penses-tu qu'elles puissent avoir un int?r?t ? Variante 1 : Le joueur A joue successivement un coup avec les blancs puis un coup avec les noirs. Le joueur B joue successivement un coup avec les blancs puis un coup avec les noirs. Le joueur A joue successivement un coup avec les blancs puis un coup avec les noirs. Etc. Le joueur A gagne si les blancs matent (quel que soit le joueur qui joue le coup d?cisif) ; le joueur B gagne si les noirs matent. Variante 2 : Le jeu se d?roule comme pour la variante 1. Le joueur A gagne s'il mate (quelle que soit la couleur qu'il joue ? ce coup-l?) ; le joueur B gagne s'il mate. Evidemment, les strat?gies sont compl?tement diff?rentes. Dans la variante 1 chacun cherche ? jouer de bons coups avec "sa" couleur et de mauvais coups avec l'autre. Dans la variante 2 ils peuvent favoriser l'une ou l'autre couleur (y compris coop?rer) mais doivent surveiller la parit? du nombre de coups avant le mat. Nicolas From abrobecker at yahoo.com Thu Nov 20 05:46:53 2008 From: abrobecker at yahoo.com (Alain BROBECKER) Date: Thu, 20 Nov 2008 02:46:53 -0800 (PST) Subject: [Retros] 1. Chess Variants -- 2 moves from one side = one white... In-Reply-To: Message-ID: <576540.25104.qm@web56203.mail.re3.yahoo.com> Hi, Reminds me of POC=Progressive orthodox chess, which is to progressive chess what helpmate is to mate. You can find it here, along with other weird variants (make sure to try magnetic chess, it's uberkewl! :) http://homepages.di.fc.ul.pt/~jpn/cv/poc.htm cu, Alain Alain Brobecker (abrobecker at yahoo.com) |_ _ _ |_ http://abrobecker.free.fr/ |_)(_|(_|| ) of Arm's Tech From joost at sanguis.xs4all.nl Sat Nov 22 11:06:24 2008 From: joost at sanguis.xs4all.nl (Joost de Heer) Date: Sat, 22 Nov 2008 17:06:24 +0100 Subject: [Retros] The Problemist, november 2008 In-Reply-To: <491C7B04.70000@sanguis.xs4all.nl> References: <491C7B04.70000@sanguis.xs4all.nl> Message-ID: <49282E00.5020206@sanguis.xs4all.nl> I forgot a correction: F1635Rc - Paul Raican 8/8/8/8/8/3B4/8/5Qk1 (2+1) +---+---+---+---+---+---+---+---+ | | . | | . | | . | | . | +---+---+---+---+---+---+---+---+ | . | | . | | . | | . | | +---+---+---+---+---+---+---+---+ | | . | | . | | . | | . | +---+---+---+---+---+---+---+---+ | . | | . | | . | | . | | +---+---+---+---+---+---+---+---+ | | . | | . | | . | | . | +---+---+---+---+---+---+---+---+ | . | | . | B | . | | . | | +---+---+---+---+---+---+---+---+ | | . | | . | | . | | . | +---+---+---+---+---+---+---+---+ | . | | . | | . | Q |*K | | +---+---+---+---+---+---+---+---+ -2 & #1, Proca retractor, Circe Parrain -1. Bb5xPd3[+wQf1] c4xQd3 -2. Qe2-d3[+wBb5] & 1. Qg2[+wBe4]# -1. ... e4xQd3 -2. Bc6-b5[+wQd3] & Be4[+wQg2]# From joost at sanguis.xs4all.nl Sat Nov 22 13:20:47 2008 From: joost at sanguis.xs4all.nl (Joost de Heer) Date: Sat, 22 Nov 2008 19:20:47 +0100 Subject: [Retros] Variables Message-ID: <49284D7F.1050306@sanguis.xs4all.nl> In the latest Problemist, there's an article about variables and AP validation of certain variables moves. Variable: A piece of known colour but unknown type, which can play as any orthodox piece (or fairy piece already present in the diagram). All possible legal substitutions of Variables for pieces are to be considered. In the play, only moves consistent with legal substitutions up to that point are legal. If a variable moves, only its departure and arrival square are considered. After each move, certain substitutions may no longer be possible, being inconsistent with the play so far. Captures, checks, mate and stalemate are only effective if they are consistent with all remaining substitutions. Examples: A. Christian Poisson Rex Multiplex 1993 8/8/8/8/8/6K1/1V6/7k (2+1) Variable b2 a) #1 b) =1 a) 1. Vb1! The variable can only be a queen or rook, and either one gives mate. 1. Va1? isn't mate, as the variable can be either a queen or a bishop. b) 1. Vd4! The variable can only be a queen or bishop, and either one gives mate. Similar to a), Vb6? isn't stalemate, as the variable can be either a queen or a rook. In diagram A, 1. Vb2-b6 Kh1-g1 is a legal sequence. White's move proves that the variable is a queen or a rook, black's move proves it's a rook. B. Tadashi Wakashima 8/8/8/8/2vR4/8/1V6/k1K5 (3+2) 1. Vb2-b4 Vc4-b3 2. Rd4-a4# With white's second move, he proves that both variables were pawns, and that black's first move was an ep capture. C. Stephen Emmerson 8/6kV/8/8/8/8/8/4K2R (3+1) 1. Vh7-h8 proves that on h7 there was a pawn. Promotion of a variable pawn is to a variable officer, so to determine the exact nature of the promotion, further moves are necessary. 1. Ve1-g1 Kg7-g6. This proves that the variable on e1 was a king, by eliminating the possibilities of it being a queen or rook, and therefore white's first move was castling, Vh1 was a rook and is now on f1. Originals: D. Geoff Foster 4vVVV/VV2Vvvv/4V3/3vVVV1/3V4/8/8/8 (11+5) +---+---+---+---+---+---+---+---+ | | . | | . |*V | V | V | V | +---+---+---+---+---+---+---+---+ | V | V | . | | V |*V |*V |*V | +---+---+---+---+---+---+---+---+ | | . | | . | V | . | | . | +---+---+---+---+---+---+---+---+ | . | | . |*V | V | V | V | | +---+---+---+---+---+---+---+---+ | | . | | V | | . | | . | +---+---+---+---+---+---+---+---+ | . | | . | | . | | . | | +---+---+---+---+---+---+---+---+ | | . | | . | | . | | . | +---+---+---+---+---+---+---+---+ | . | | . | | . | | . | | +---+---+---+---+---+---+---+---+ h==9, Variables 1. Vh7-h5 Vg5-h6 2. Vg7-g5 Vf5-g6 3. Vf7-f5 Ve5-f6 4. Ve8-b5[=bBQ, d5=bK] Ve7-h7[=wRQ] 5. Kd5-c6 Vb7-g7[=wR] 6. Vb5-h5!![=bQ,f6=wP,g6=wP,h6=wP] Va7-f7[=wRQ] 7. Qh5-e5 Ve6-e7[=wP] 8. Kc6-d7[vf8~S] Vd4xe5[=wPB] 9. Kd7-e8[Vf8=B,Vf7=R] Ve5-e6[=wP]== Three e.p. captures on move 1-3 are validated on move 6. Note that not all variables are known (Vh7=wRQ, Vg8!=wB, Vh8!=wB), but all substitutions consistent with the previous play lead to stalemate. The beginposition is: 4qBVV/RR2Vppp/4P3/3kPPP1/3P4/8/8/8 E. Ian Shanahan 8/v7/8/1vV5/v4v2/6v1/6v1/4V2V (3+6) +---+---+---+---+---+---+---+---+ | | . | | . | | . | | . | +---+---+---+---+---+---+---+---+ |*V | | . | | . | | . | | +---+---+---+---+---+---+---+---+ | | . | | . | | . | | . | +---+---+---+---+---+---+---+---+ | . |*V | V | | . | | . | | +---+---+---+---+---+---+---+---+ |*V | . | | . | |*V | | . | +---+---+---+---+---+---+---+---+ | . | | . | | . | |*V | | +---+---+---+---+---+---+---+---+ | | . | | . | | . |*V | . | +---+---+---+---+---+---+---+---+ | . | | . | | V | | . | V | +---+---+---+---+---+---+---+---+ ser-=7, Variables 1. Vc5-b6 [b6!=wRS, a7!=bK] 2. Vb6xa7 3. Va7-a8[[c5]=wKQP, b5!=bK, a8!=wP] 4. Va8xg2 [g2=wQB;[c5]=wQP] 5. Ve1-g1 [g1=wQRK] 6. Vf1xf4! [5. OO!, g1=wK, [h1]=wR, a4!=bK, g3=bK, g2=wB => [c5]=wP, 1. cb6ep!] 7. Rf4xa4= Monochromatic Valladao task, ideal stalemate. F. Mark Ridley 8/8/8/8/1Vv5/8/V1R5/4V1v1 (2+4) +---+---+---+---+---+---+---+---+ | | . | | . | | . | | . | +---+---+---+---+---+---+---+---+ | . | | . | | . | | . | | +---+---+---+---+---+---+---+---+ | | . | | . | | . | | . | +---+---+---+---+---+---+---+---+ | . | | . | | . | | . | | +---+---+---+---+---+---+---+---+ | | V |*V | . | | . | | . | +---+---+---+---+---+---+---+---+ | . | | . | | . | | . | | +---+---+---+---+---+---+---+---+ | V | . | R | . | | . | | . | +---+---+---+---+---+---+---+---+ |[.]| | . | | V | |*V | | +---+---+---+---+---+---+---+---+ ser-h#3, Variables, magic square a1 1. Vc4-b3 [b3~bRS, a2~wK] 2. Vb3xa2 [a2~bK, g1=bK] 3. a2-a1=wV[[c4]=bQP, b4~wK, e1=wK] Ke1-c1 => OOO# => d1=R => [c4]=P => 1. cb3ep => b4=wP] Valladao, all three aspects involve the same variable. A Fairyable is a Variable that can only be substituted by a fairy piece already present in the diagram. G. Stephen Emmerson 2V5/6vG/5Pl1/1Kp5/1p3kl1/1L5G/7P/6G1 (8+6) +---+---+---+---+---+---+---+---+ | | . | V | . | | . | | . | +---+---+---+---+---+---+---+---+ | . | | . | | . | |*V | G | +---+---+---+---+---+---+---+---+ | | . | | . | | P |*L | . | +---+---+---+---+---+---+---+---+ | . | K |*P | | . | | . | | +---+---+---+---+---+---+---+---+ | |*P | | . | |*K |*L | . | +---+---+---+---+---+---+---+---+ | . | L | . | | . | | . | G | +---+---+---+---+---+---+---+---+ | | . | | . | | . | | P | +---+---+---+---+---+---+---+---+ | . | | . | | . | | G | | +---+---+---+---+---+---+---+---+ h#2; fairyables c8, g7; grasshopper g1, h3, h7; locust b3, g4, g6 b) Gg1->h8 a) 1. Vg7-e5 Gh7-f5 [e5=bL, -wPf6] 2. Lg6xf5-e4 Vc8-c4 (c4=L? self-check from e5, since c5 is captured => c4=G => #) b) 1. Vg7-g5[=bG => +) Gh3-f5 2. Lg4xf5-e6+ Vc8-c4 (c4=G?? => c4=L => #). B1 sets up the proof of the wV on W2 by the attack on the wK, proving the attack on the bK. From mvalg at velucchi.it Sun Nov 23 09:05:29 2008 From: mvalg at velucchi.it (Mario Velucchi) Date: Sun, 23 Nov 2008 15:05:29 +0100 Subject: [Retros] Fwd: quick composing In-Reply-To: <20081121114506.rpndimrav4wwo0o0@mail.zih.tu-dresden.de> References: <20081121114506.rpndimrav4wwo0o0@mail.zih.tu-dresden.de> Message-ID: <29b3a48a0811230605jccf49c9s84f71c4854fae198@mail.gmail.com> ---------- Forwarded message ---------- From: Torsten Linss Date: Fri, Nov 21, 2008 at 11:45 AM Subject: quick composing To: ... Dear all, please not the following announcement: http://www.math.tu-dresden.de/~torsten/problem/ausschr.pdf Torsten (Lin\ss) ------------------------------------------------------------------------ Workshop Chess and Mathematics 21st-23rd November 2008 in Dresden click here: http://www.math.tu-dresden.de/num/chess2008/ ------------------------------------------------------------------------ Jun.-Prof. Dr. Torsten Lin? Institut f. Numerische Mathematik office: Willersbau C312 TU Dresden telephone: +49-351-463-35073 D-01062 Dresden skype: torstenlinss Germany email: Torsten.Linss at tu-dresden.de www: http://www.math.tu-dresden.de/~torsten ------------------------------------------------------------------------ http://de.youtube.com/watch?v=jCQdXXkJD_8&NR=1 ------------------------------------------------------------------------ -- best .marioV -- Mario Velucchi via Emlia, 106 I-56121 Pisa ? 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Name: ausschr.pdf Type: application/pdf Size: 32456 bytes Desc: not available Url : From G.A.Rol at umcutrecht.nl Mon Nov 24 06:45:14 2008 From: G.A.Rol at umcutrecht.nl (Rol, Guus) Date: Mon, 24 Nov 2008 12:45:14 +0100 Subject: [Retros] Variables In-Reply-To: <49284D7F.1050306@sanguis.xs4all.nl> References: <49284D7F.1050306@sanguis.xs4all.nl> Message-ID: That is certainly an interesting variation, "Variable Pieces". I am willing to drop the V(ao) in favor of the V(ariable) :-) I haven't read the original article so I can't be sure of the role it assigns to the ? posteriori attribute, but going by the examples I suspect that the AP-qualification is misused here. The role adaptation of the Variable is actually an exquisite example of Post (F)actum logic. Not attempting a full expos? of AP-logic here, I will just mention two essential characteristics of AP-logic that are missing: (1) All AP-logic contains "justification by proxy", as in "parental guidance" implying "we don't trust the kid, unless accompanied by a parent (the proxy)". In chess: "we don't trust the e.p.-right, except when implied and validated by the manifested castling-right". There is no proxy in the resolution of the Variable role. (2) Since the proxy operates independent of the AP-initiator (the e.p. move) there is always the possibility that ? posteriori justification through the proxy does not take place. At this point the whole variation becomes "virtual", effectively non-existent. This option is not present when resolving the Variable pieces Why the "Variable-logic" can be categorized as "Post (F)actum logic" is another story that warrants a longer analysis. At this point I will only note that the move Kh1-g1 in the paragraph "In diagram A, 1. Vb2-b6 Kh1-g1 is a legal sequence; White's move proves that the variable is a queen or a rook, black's move proves it's a rook" plays the same role as the move "black 0-0" would be play in a mutually-exclusieve post factum problem where it eliminates white's castling right. Guus Rol From joost at sanguis.xs4all.nl Mon Nov 24 07:09:26 2008 From: joost at sanguis.xs4all.nl (Joost de Heer) Date: Mon, 24 Nov 2008 13:09:26 +0100 Subject: [Retros] Variables In-Reply-To: References: <49284D7F.1050306@sanguis.xs4all.nl> Message-ID: <492A9976.9090200@sanguis.xs4all.nl> > I haven't read the original article so I can't be sure of the role it > assigns to the ? posteriori attribute, but going by the examples I > suspect that the AP-qualification is misused here. The role > adaptation of the Variable is actually an exquisite example of Post > (F)actum logic. I don't think Stephen intended to use AP in the same sense as it is used in retros. The paragraph that mentions 'a posteriori' is: [Diagram B, after moves 1. Vb2-b4 Vc4-b3] "Similarly, if White follows with 2. Ra4, this is legal only if b4 is vacant, so again ep capture must have taken place, and if it wasn't known before, now it is known that b3 must be a bP. This is a posteriori justification, not prove it by doing it." You're probably right in saying PF is a better name. Joost From G.A.Rol at umcutrecht.nl Mon Nov 24 10:49:44 2008 From: G.A.Rol at umcutrecht.nl (Rol, Guus) Date: Mon, 24 Nov 2008 16:49:44 +0100 Subject: [Retros] Variables In-Reply-To: <492A9976.9090200@sanguis.xs4all.nl> References: <49284D7F.1050306@sanguis.xs4all.nl> <492A9976.9090200@sanguis.xs4all.nl> Message-ID: That makes things more interesting Joost. There is more to Stephens comments than just the "Variable Piece". He also adjusts the notation of moves by writing down "Vc4-b3" instead of "Vc4xb3" or "Vc4xb3 e.p." as would be usual. That introduces new unknowns (captures) besides the Variable Piece. One would need to peel off the layers to see if there is anything AP hidden inside (which I doubt). Note that the e.p. capture needs no justification since the preceding double step move is a 100% certainty. The playing options of a Pawn are therefore as clearly defined as those of any other piece and need no justification. By the way, I've encountered PbyD (prove it by doing it) before and I've always wondered if that could mean something different from PF-strategy. If it included arbitrary e.p. captures as well, what would they need AP-logic for? Guus Rol -----Oorspronkelijk bericht----- Van: retros-bounces at janko.at [mailto:retros-bounces at janko.at] Namens Joost de Heer Verzonden: maandag 24 november 2008 13:09 Aan: The Retrograde Analysis Mailing List Onderwerp: Re: [Retros] Variables > I haven't read the original article so I can't be sure of the role it > assigns to the ? posteriori attribute, but going by the examples I > suspect that the AP-qualification is misused here. The role adaptation > of the Variable is actually an exquisite example of Post (F)actum > logic. I don't think Stephen intended to use AP in the same sense as it is used in retros. The paragraph that mentions 'a posteriori' is: [Diagram B, after moves 1. Vb2-b4 Vc4-b3] "Similarly, if White follows with 2. Ra4, this is legal only if b4 is vacant, so again ep capture must have taken place, and if it wasn't known before, now it is known that b3 must be a bP. This is a posteriori justification, not prove it by doing it." You're probably right in saying PF is a better name. Joost From joost at sanguis.xs4all.nl Mon Nov 24 11:12:18 2008 From: joost at sanguis.xs4all.nl (Joost de Heer) Date: Mon, 24 Nov 2008 17:12:18 +0100 Subject: [Retros] Variables In-Reply-To: References: <49284D7F.1050306@sanguis.xs4all.nl> <492A9976.9090200@sanguis.xs4all.nl> Message-ID: <492AD262.7000504@sanguis.xs4all.nl> > That makes things more interesting Joost. There is more to Stephens > comments than just the "Variable Piece". He also adjusts the notation > of moves by writing down "Vc4-b3" instead of "Vc4xb3" or "Vc4xb3 > e.p." as would be usual. That introduces new unknowns (captures) > besides the Variable Piece. One would need to peel off the layers to > see if there is anything AP hidden inside (which I doubt). Note that > the e.p. capture needs no justification since the preceding double > step move is a 100% certainty. The playing options of a Pawn are > therefore as clearly defined as those of any other piece and need no > justification. > By the way, I've encountered PbyD (prove it by doing it) before and > I've always wondered if that could mean something different from > PF-strategy. If it included arbitrary e.p. captures as well, what > would they need AP-logic for? In the given diagram, Vb2-b4 Vc4-b3 could be Rb2-b4 Bc4-b3 too (and if the position was totally different, it could also mean Pb2-b4 Kc4-b3, or Qb2-b4 Qc4-b3). To quote from the article: "In fact, Tadashi[ Wakashima, the inventor of Variables, JdH]'s intention is that the moves should be written as 1. Vb2-b4 Vc4-b3. As this is compatible also with 1. Rb2-b4 Bc4-b3, it cannot simply be asserted that capture has taken place; only departure and arrival squares can be claimed. If c4 was a P (or a V that has already been shown to be a P), then c4-b3 is consistent only with ep capture." [...] "The same justification must be made for promotions; in C [wVe1 wVh1 wVh7 bKg7] one cannot claim to play h7-h8=S, but instead 1. Vh7-h8 only (note that this shows the wVh7 to be a pawn); the particular promotion must be justified by later play. And Ve1-g1 is not sufficient to justify this move as OO; but if followed by Kg7-g6 the alternatives Re1-g1 and Qe1-g1 are ruled out leaving only OO, so we know that g1=K and Vh1 is now on f1 and is a rook." As I said before, don't confuse Variables AP logic with retro AP logic. For variables, later moves can be used to rule out possibilities, or to (re)move pieces that aren't directly affected by the variable move itself. The AP terminology is used in the latter sense. Joost From G.A.Rol at umcutrecht.nl Tue Nov 25 04:12:49 2008 From: G.A.Rol at umcutrecht.nl (Rol, Guus) Date: Tue, 25 Nov 2008 10:12:49 +0100 Subject: [Retros] Variables In-Reply-To: <492AD262.7000504@sanguis.xs4all.nl> References: <49284D7F.1050306@sanguis.xs4all.nl> <492A9976.9090200@sanguis.xs4all.nl> <492AD262.7000504@sanguis.xs4all.nl> Message-ID: It is always hard to argue with an inventor considering his prerogative to set the rules. Nevertheless it must be noted that there appears to be a basic misunderstanding of the inventor regarding "notation systems". Starting from the real world, the "Variable Piece" is easy to implement. Take a undistinguished piece of white or black wood, write VP on it and put it on a chess board. With the game or solution underway the reduction of its possible roles can be scribbled in the wood, "it is now not a rook", "and not now a bishop either" etc. However, when executing a move with the VP you must show precisely what the chosen action entails. If it deletes another entity, the entity must disappear, en passant or otherwise. The function of a notation system is to identify the precise action that has taken place on the board in the real world. Apparently the inventor is not happy enough with his variable pieces, when he adds to it a mysterious use of the notation system in order to protect to VP mysteries. If we follow the thought line of the inventor we might as well decide to use an even shorter notation like Vb6, only identifying the target square and creating even more mystery on what VP to move to b6. Actually, even in standard chess I can create ? posteriori justifications by using underdetermined notations. But frankly, must we take serious a solution which correctness does not depend on what you execute on the board but on the notation system you use? Yes, it is possible to have different understandings of the ? posteriori concept. From a science philosophical viewpoint one might even consider PF-logic as ? posteriori. Nevertheless there is a restriction pertaining to the redundancy of terminology. If a proper analysis shows that "the a.p. justification of the e.p. move" is nothing but the combination of a clever notation trick and standard "proof it by doing it", than the assignment of the "? posteriori" qualification amounts to nothing but the suggestion of content that isn't really there. My current intuition is that the ? posteriori identification of the two Pawns involved in the e.p. move is no different from the ? posteriori "coming out" of a Queen identity 23 moves after its disguised appearance as a VP. Guus Rol -------------- In the given diagram, Vb2-b4 Vc4-b3 could be Rb2-b4 Bc4-b3 too (and if the position was totally different, it could also mean Pb2-b4 Kc4-b3, or Qb2-b4 Qc4-b3). To quote from the article: "In fact, Tadashi[ Wakashima, the inventor of Variables, JdH]'s intention is that the moves should be written as 1. Vb2-b4 Vc4-b3. As this is compatible also with 1. Rb2-b4 Bc4-b3, it cannot simply be asserted that capture has taken place; only departure and arrival squares can be claimed. If c4 was a P (or a V that has already been shown to be a P), then c4-b3 is consistent only with ep capture." [...] "The same justification must be made for promotions; in C [wVe1 wVh1 wVh7 bKg7] one cannot claim to play h7-h8=S, but instead 1. Vh7-h8 only (note that this shows the wVh7 to be a pawn); the particular promotion must be justified by later play. And Ve1-g1 is not sufficient to justify this move as OO; but if followed by Kg7-g6 the alternatives Re1-g1 and Qe1-g1 are ruled out leaving only OO, so we know that g1=K and Vh1 is now on f1 and is a rook." As I said before, don't confuse Variables AP logic with retro AP logic. For variables, later moves can be used to rule out possibilities, or to (re)move pieces that aren't directly affected by the variable move itself. The AP terminology is used in the latter sense. Joost From Eric.Angelini at kntv.be Tue Nov 25 05:42:52 2008 From: Eric.Angelini at kntv.be (Eric Angelini) Date: Tue, 25 Nov 2008 11:42:52 +0100 Subject: [Retros] Variables Message-ID: NOT : ? priori ? posteriori BUT a priori a posteriori ... as this is latin ! (and not french) Best, ?. -----Message d'origine----- De : retros-bounces at janko.at [mailto:retros-bounces at janko.at] De la part de Rol, Guus Envoy? : mardi 25 novembre 2008 10:13 ? : The Retrograde Analysis Mailing List Objet : Re: [Retros] Variables It is always hard to argue with an inventor considering his prerogative to set the rules. Nevertheless it must be noted that there appears to be a basic misunderstanding of the inventor regarding "notation systems". Starting from the real world, the "Variable Piece" is easy to implement. Take a undistinguished piece of white or black wood, write VP on it and put it on a chess board. With the game or solution underway the reduction of its possible roles can be scribbled in the wood, "it is now not a rook", "and not now a bishop either" etc. However, when executing a move with the VP you must show precisely what the chosen action entails. If it deletes another entity, the entity must disappear, en passant or otherwise. The function of a notation system is to identify the precise action that has taken place on the board in the real world. Apparently the inventor is not happy enough with his variable pieces, when he adds to it a mysterious use of the notation system in order to protect to VP mysteries. If we follow the thought line of the inventor we might as well decide to use an even shorter notation like Vb6, only identifying the target square and creating even more mystery on what VP to move to b6. Actually, even in standard chess I can create ? posteriori justifications by using underdetermined notations. But frankly, must we take serious a solution which correctness does not depend on what you execute on the board but on the notation system you use? Yes, it is possible to have different understandings of the ? posteriori concept. From a science philosophical viewpoint one might even consider PF-logic as ? posteriori. Nevertheless there is a restriction pertaining to the redundancy of terminology. If a proper analysis shows that "the a.p. justification of the e.p. move" is nothing but the combination of a clever notation trick and standard "proof it by doing it", than the assignment of the "? posteriori" qualification amounts to nothing but the suggestion of content that isn't really there. My current intuition is that the ? posteriori identification of the two Pawns involved in the e.p. move is no different from the ? posteriori "coming out" of a Queen identity 23 moves after its disguised appearance as a VP. Guus Rol -------------- In the given diagram, Vb2-b4 Vc4-b3 could be Rb2-b4 Bc4-b3 too (and if the position was totally different, it could also mean Pb2-b4 Kc4-b3, or Qb2-b4 Qc4-b3). To quote from the article: "In fact, Tadashi[ Wakashima, the inventor of Variables, JdH]'s intention is that the moves should be written as 1. Vb2-b4 Vc4-b3. As this is compatible also with 1. Rb2-b4 Bc4-b3, it cannot simply be asserted that capture has taken place; only departure and arrival squares can be claimed. If c4 was a P (or a V that has already been shown to be a P), then c4-b3 is consistent only with ep capture." [...] "The same justification must be made for promotions; in C [wVe1 wVh1 wVh7 bKg7] one cannot claim to play h7-h8=S, but instead 1. Vh7-h8 only (note that this shows the wVh7 to be a pawn); the particular promotion must be justified by later play. And Ve1-g1 is not sufficient to justify this move as OO; but if followed by Kg7-g6 the alternatives Re1-g1 and Qe1-g1 are ruled out leaving only OO, so we know that g1=K and Vh1 is now on f1 and is a rook." As I said before, don't confuse Variables AP logic with retro AP logic. For variables, later moves can be used to rule out possibilities, or to (re)move pieces that aren't directly affected by the variable move itself. The AP terminology is used in the latter sense. Joost _______________________________________________ Retros mailing list Retros at janko.at http://www.pairlist.net/mailman/listinfo/retros From G.A.Rol at umcutrecht.nl Tue Nov 25 05:58:48 2008 From: G.A.Rol at umcutrecht.nl (Rol, Guus) Date: Tue, 25 Nov 2008 11:58:48 +0100 Subject: [Retros] Variables In-Reply-To: References: Message-ID: Thank you, Eric. You are right. A serious argument deserves correct spelling. Guus Rol. -----Oorspronkelijk bericht----- Van: retros-bounces at janko.at [mailto:retros-bounces at janko.at] Namens Eric Angelini Verzonden: dinsdag 25 november 2008 11:43 Aan: The Retrograde Analysis Mailing List Onderwerp: Re: [Retros] Variables NOT : ? priori ? posteriori BUT a priori a posteriori ... as this is latin ! (and not french) Best, ?. From mri_two at t-online.de Fri Nov 28 12:17:50 2008 From: mri_two at t-online.de (Mario Richter) Date: Fri, 28 Nov 2008 18:17:50 +0100 Subject: [Retros] Die Schwalbe Heft 233 Oct 2008, problem 13883 References: <48F0A103.8000702@sanguis.xs4all.nl> Message-ID: <000a01c9517d$3e35b9c0$0100a8c0@he2p306> > 13883 - Bernd Gr?frath > rsb1kb1q/pppp1p2/7p/4p3/6P1/8/PPPPP3/RSBQK1SR (13+13) > +---+---+---+---+---+---+---+---+ > |*R |*S |*B | . |*K |*B | |*Q | > +---+---+---+---+---+---+---+---+ > |*P |*P |*P |*P | . |*P | . | | > +---+---+---+---+---+---+---+---+ > | | . | | . | | . | |*P | > +---+---+---+---+---+---+---+---+ > | . | | . | |*P | | . | | > +---+---+---+---+---+---+---+---+ > | | . | | . | | . | P | . | > +---+---+---+---+---+---+---+---+ > | . | | . | | . | | . | | > +---+---+---+---+---+---+---+---+ > | P | P | P | P | P | . | | . | > +---+---+---+---+---+---+---+---+ > | R | S | B | Q | K | | S | R | > +---+---+---+---+---+---+---+---+ > PG 8.0 (Losing chess) I don't know, if this has already been noticed, but there is a WHITE BISHOP on h1! Best, mario From retromode at web.de Fri Nov 28 12:38:58 2008 From: retromode at web.de (=?iso-8859-15?Q?Bernd_Gr=E4frath?=) Date: Fri, 28 Nov 2008 18:38:58 +0100 Subject: [Retros] Die Schwalbe Heft 233 Oct 2008, problem 13883 Message-ID: <1345607918@web.de> Dear Mario, thank you for mentioning this! (The printed version is correct.) Best wishes, Bernd > -----Urspr?ngliche Nachricht----- > Von: "Mario Richter" > Gesendet: 28.11.08 18:18:14 > An: "The Retrograde Analysis Mailing List" > Betreff: Re: [Retros] Die Schwalbe Heft 233 Oct 2008, problem 13883 > > 13883 - Bernd Gr?frath > > rsb1kb1q/pppp1p2/7p/4p3/6P1/8/PPPPP3/RSBQK1SR (13+13) > > +---+---+---+---+---+---+---+---+ > > |*R |*S |*B | . |*K |*B | |*Q | > > +---+---+---+---+---+---+---+---+ > > |*P |*P |*P |*P | . |*P | . | | > > +---+---+---+---+---+---+---+---+ > > | | . | | . | | . | |*P | > > +---+---+---+---+---+---+---+---+ > > | . | | . | |*P | | . | | > > +---+---+---+---+---+---+---+---+ > > | | . | | . | | . | P | . | > > +---+---+---+---+---+---+---+---+ > > | . | | . | | . | | . | | > > +---+---+---+---+---+---+---+---+ > > | P | P | P | P | P | . | | . | > > +---+---+---+---+---+---+---+---+ > > | R | S | B | Q | K | | S | R | > > +---+---+---+---+---+---+---+---+ > > PG 8.0 (Losing chess) > > I don't know, if this has already been noticed, > but there is a WHITE BISHOP on h1! > > Best, > > mario > > _______________________________________________ > Retros mailing list > Retros at janko.at > http://www.pairlist.net/mailman/listinfo/retros > _________________________________________________________________________ Sensationsangebot nur bis 30.11: WEB.DE FreeDSL - Telefonanschluss + DSL f?r nur 16,37 Euro/mtl.!* http://dsl.web.de/?ac=OM.AD.AD008K13805B7069a