# StrateGems

No. 51, Jul-Sep 2010

R165 -

StrateGems 51, Jul-Sep 2010

9+13. hc#2* a) diagram b) Sd8->c7

[3Nbrrn/3ppPkp/1B1pn1Bp/3P1K1p/3Pp2P/4P3/8/8]

Solution

The initial position is legal with 7 black captures: Pb7xc6xd5xe4, Pc7xd6, Pf7xg6xh5, Pg7xh6. Solution: a) 1...dxe6 2.dxe6+ Sxe6#, 1.Sxd8 Bxd8 2.e5 Bf6# (not 1.Sxd4+? Bxd4+ 2.e5 dxe6 ep?? – as the last move could also have been 2.c7xd6).

b) 1.Sxd4+ Bxd4+ 2.e5 d5xe6 ep#! The position after black’s 2nd move could arise only after e7-e5 (the last move e7xd6 or f6xe5 would be illegal – one capture too much)

R166 -

StrateGems 51, Jul-Sep 2010

Dedicated to Andrei Frolkin

12+10. Legal?

[8/4p2p/8/8/1PPP4/BrbkPPP1/1p1PqprP/bQ1B3K]

Solution

Retract: -1.Qa2(c1)xQb1+ Qc2-b1 -2.Qb1-a2(c1) Qc1xRc2 -3.Qa2-b1 Qb1-c1 -4.Rc1xSc2 Se1-c2 -5.Rc2-c1 Qc1-b1 -6.Qb1-a2 a2-a1B -7.Qa1-b1 Qb1-c1 -8.Rc1-c2 Sc2xRe1 -9.Rg1-e1 Se1-c2 -10.Rc2-c1 Qf1-e2 -11.Rc1-c2 Ke2-d3 -12.Bc2-d1+ Sd3-e1 -13.Rd1-c1, further retracting bPe3xSf2 to open the South-East cage.

Note that -9.Rg1-e1 is necessary for parity reasons; otherwise a retro-opposition occurs. A self-extracting Chinese puzzle: Starting with a sole Queen, units uncapture each other, until almost all of the available space is filled; then they start moving busily. (A)

R167 -

StrateGems 51, Jul-Sep 2010

Dedicated to Andrei Kornilov

15+11. Release the position

[8/3p1pp1/8/8/7P/PPPPPPkp/pQRrRrP1/qbNBb1NK]

Solution

Retract: -1.Rf1-f2 Rf2-e2 -2.Re2-d2 Rd2-c2 -3.Bc2-b1 Qb1-b2 -4.Qb2-a1 Qa1-b1 -5.Bb1-c2 Rc2-d2 -6.Rd2-e2 Re2-f2 -7.Bf2-e1 Re1-e2 -8.Re2-d2 Rd2-c2 -9.Bc2-b1 Qb1-a1 -10.Qa1-b2 Qb2-b1 -11.Bb1-c2 Rc2-d2 -12.Rd2-e2 Be2-d1 -13.Rd1-d2 Rd2-c2 -14.Bc2-b1 Qb1-b2 -15.Qb2-a1 Qa1-b1 -16.Bb1-c2 Rc2-d2 -17.d2-d1R Rd1-e1 -18.Re1-f1 Bf1-e2 -19.Kf4-g3 e2-e3+ etc. Tries: a) -7.Kg4-g3 f2-f3+ creates an illegal cluster in the a1-f3 rectangle. b) -17.Rd2-d1 and 19…e2-e3 creates an illegal cluster in the a1-f3 rectangle. c) -17.Rd2-d1 Rd1-e1 -18.Bf1-e2, then retract the black bishop from f2 to d2 and f2-f3 results in retro-stalemate for white.

Three crucial bishop moves need to be unplayed: Be1-f2, Bd1-e2 and Be2-f1. Every such move changes parity, and the Rooks serve as parity-preserving fluid. Thus, between every two crucial moves a parity-restoring triangulation maneuver needs to be performed by the two Queens. (A)

R168 -

StrateGems 51, Jul-Sep 2010

16+16. Remove units for an IC

[Note by JhH: This problem is unfortunately anticipated by Andrew Buchanan, who published an almost identical IC on his website. ]

[rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR]

Solution

Remove a1, a2, a7, a8, b1, b8, g1, g8, h1, h2, h7, h8, for an Illegal Cluster.

Joost de Heer reports an exact anticipation. See {C00} in Andrew Buchanan’s website: http://www.anselan.com/CHEsols.html

P0270 -

StrateGems 51, Jul-Sep 2010

14+14. Proof game in 5.0 moves (Anticirce)

[1nbqkbnr/1pppppp1/8/7p/8/8/1PPPPPPP/1NBQKBNR]

Solution

1.a4 Sc6 2.a5 Sxa5(Sb8) 3.Rxa7(Ra1) h5 4.Ra6 Rh6 5.Rxh6(Ra1) Rxa1(Rh8)

P0271 -

StrateGems 51, Jul-Sep 2010

12+12. Proof game in 9.5 moves (Losing chess)

[rnb1kb2/pppp1p1q/8/3n4/8/5P2/PPPPP3/RNBQK2B]

Solution

1.h4 e5 2.h5 Se7 3.Sf3 e4 4.h6 exf3 5.hxg7 fxg2 6.gxh8K gxh1K 7.Kxh7 Sd5 8.f3 Qh4 9.Bg2 Qxh7 10.Bxh1

Double setting of Ceriani/Frolkin Kings, one of them being a Schnoebelen King (A)

P0272 -

StrateGems 51, Jul-Sep 2010

14+13. Proof game in 13.5 moves (Immun chess)

[rnb1kbnr/2pp1ppp/3p2Q1/8/2P5/2N2P1N/P2PPP1P/RB3KR1]

Solution

1.b3 a5 2.Ba3 a4 3.Bd6 exd6 4.c4 Qf6 5.Sc3 Qf3 6.gxf3 axb3 7.Bh3 b2 8.Kf1 b1Q 9.Qxb1 b5 10.Qg6 b4 11.Bf5 b3 12.Sh3 b2 13.Rg1 b1Q+ 14.Bxb1

Two Schnoebelen Queens on the same square.

P0273 -

StrateGems 51, Jul-Sep 2010

14+13. Proof game in 15.0 moves

[4k1qr/pp2ppp1/8/1b1p4/3n1B1p/3P4/Pp1NPPPP/2RQKBNR]

Solution

P0273 (Thornton) 1.d3 c5 2.Bf4 c4 3.Sd2 c3 4.Rc1 cxb2 5.c4 Sc6 6.c5 Sd4 7.c6 d5 8.c7 Bd7 9.c8R Bb5 10.Rxa8 Qb8 11.Rc8+ Kd7 12.Rxf8 h5 13.Rxg8 Qxg8 14.Rc8 h4 15.Rc1 Ke8

Bristol line clearance on the 8th rank, anti-Pronkin and the theme of G.Donati-50 JT. (A)

P0274 -

StrateGems 51, Jul-Sep 2010

13+15. Proof game in 15.5 moves

[kr4nr/ppp3pp/3p1q2/4bp2/nP6/5P2/P2PP1PP/RKBb1BNR]

Solution

) 1.Sc3 Sa6 2.Sd5 Sc5 3.Sxe7 Sa4 4.Sf5 Bd6 5.b4 Be5 6.Ba3 d6 7.Qb1 Bxf5 8.Kd1 Bxc2+ 9.Kc1 f5 10.Qb3 Qf6 11.Qg3 0-0-0 12.f3 Kb8 13.Qe1 Ka8 14.Qd1 Bxd1 15.Kb1 Rb8 16.Bc1

The white Queen performs a 5-move round-trip, only to be captured on her home square.

P0275 -

StrateGems 51, Jul-Sep 2010

15+11. Proof game in 16.5 moves

[4k3/p1p2pr1/rn1p4/7p/6Q1/qPPP4/1Pb1PPP1/RNB1KBNR]

Solution

1.h4 b5 2.h5 b4 3.h6 b3 4.hxg7 h5 5.gxf8B Rh7 6.Bxe7 Qxe7 7.c3 Qa3 8.Qc2 d6 9.Qg6 Bf5 10.axb3 Bc2 11.d3 Sd7 12.Bh6 Rb8 13.Bf8 Rb6 14.Qxg8 Ra6 15.Qg4 Sb6 16.Bh6 Rg7 17.Bc1

An anti-Pronkin Bishop serves as a screen for her Majesty, before returning home.

P0276 -

StrateGems 51, Jul-Sep 2010

13+15. Proof game in 17.0 moves

[2bqk2r/1pp2p1p/nppp2n1/6pr/8/2P5/1PP2PPP/RNB1KBNR]

Solution

1.e4 g6 2.e5 Bg7 3.e6 Bc3 4.dxc3 Kf8 5.Qd6 exd6 6.e7+ Kg7 7.e8Q Kf6 8.Qe3 Se7 9.Qb6 axb6 10.a3 Ra5 11.a4 Rh5 12.a5 g5 13.a6 Sg6 14.a7 Ke7 15.a8Q Ke8 16.Qa4 Sa6 17.Qc6 dxc6

Two Phoenix Ceriani/Frolkin Queens; one requiring a 5-move round-trip by the black King.

P0277 -

StrateGems 51, Jul-Sep 2010

Dedicated to Guy Sobrecases

13+15. Proof game in 19.0 moves

[2b3r1/1pn1p1pp/2pqpnpr/1p4k1/8/8/1PPPP1PP/RNBQKB1R]

Solution

1.Sf3 a6 2.Sd4 Ra7 3.Sb5 axb5 4.a4 Ra6 5.a5 Rh6 6.a6 c6 7.a7 Qc7 8.a8S Qd6 9.Sc7+ Kd8 10.Se6+ Ke8 11.Sxf8 Sa6 12.Sg6 fxg6 13.f3 Kf7 14.f4 Kf6 15.f5 Kg5 16.f6 Sc7 17.f7 Sf6 18.f8S Rg8 19.Se6+ dxe6

Two Phoenix Ceriani/Frolkin Knights. Nice tempo effects.

P0278 -

StrateGems 51, Jul-Sep 2010

11+14. Proof game in 27.5 moves

[1rbq1bn1/2p4R/b2pk1pQ/6b1/1nN5/3br3/P1P2P2/1KBR1BN1]

Solution

1.b4 h5 2.b5 h4 3.b6 h3 4.bxa7 b5 5.d4 b4 6.d5 b3 7.d6 b2 8.dxe7 bxc1B 9.Qd6 Bg5 10.Sd2 hxg2 11.0-0-0 Rh3 12.Kb1 Re3 13.h4 f5 14.h5 f4 15.h6 f3 16.h7 fxe2 17.h8B exf1B 18.Rh7 Bfa6 19.Qh6 g6 20.Bb2 d6 21.Bc1 Kd7 22.e8B+ Ke6 23.Bb5 Sc6 24.Bf1 Sb4 25.Sc4 Rb8 26.a8B gxf1B 27.Bg2 Bd3 28.Bf1

Six Bishop promotions; three of them become Pronkin pieces.

P0279 -

StrateGems 51, Jul-Sep 2010

After Michel Caillaud

15+11. Proof game in 28.5 moves

[rnbqkb1r/p2p2p1/1R5n/BB4B1/R1KP4/3P2P1/P2B2P1/1Q1NN3]

Solution

1.f4 c5 2.f5 c4 3.f6 c3 4.fxe7 cxb2 5.Sc3 b1Q 6.exd8B Qb6 7.Bg5 Qd8 8.e4 b5 9.e5 b4 10.e6 b3 11.e7 b2 12.exd8B b1Q 13.Ba5 Qb6 14.Rb1 Qd8 15.Rb6 f5 16.Bb5 f4 17.Ke2 f3+ 18.Kd3 f2 19.Sf3 f1S 20.Se1 Sg3 21.hxg3 h5 22.Rh4 Sh6 23.Ra4 h4 24.Kc4 h3 25.d4 h2 26.Bcd2 h1S 27.Qb1 Sf2 28.Sd1 Sd3 29.cxd3

TF proof game with Pronkin (qq) and Ceriani/Frolkin (ss) (A)

P0280 -

StrateGems 51, Jul-Sep 2010

Dedicated to Nikos Kazantzakis and to the Crete 2010 WCCC

13+12. Proof game in 29.5 moves

[1nrn4/p3bk1p/4R2P/4ppqP/4PBpr/7N/B2P3P/RN1QK3]

Solution

1.a4 d5 2.a5 d4 3.a6 d3 4.axb7 Sa6 5.b8Q dxc2 6.Qb3 Rb8 7.Sh3 Rb4 8.Rg1 Rh4 9.e4 cxd1B 10.Bc4 Bh5 11.Qd1 c5 12.Ba2 c4 13.b4 c3 14.Bb2 c2 15.Be5 cxd1B 16.Bf4 e5 17.g4 Se7 18.gxh5 Sc6 19.h6 Bh5 20.Rg6 Bcg4 21.f3 f5 22.Re6+ Kf7 23.fxg4 g5 24.gxh5 g4 25.b5 Qg5 26.b6 Be7 27.b7 Rc8 28.b8Q Sd8 29.Qb3 Sb8 30.Qd1

This is a PG of the Future (TFPG: see the definition, discussion and examples in the Retro Mailing List archives http://www.pairlist.net/pipermail/retros/2008-October/002716.html), which shows double Pronkin Queens vs double Ceriani/Frolkin Bishops. This combination was already shown by Michel Caillaud (Problemesis 1999, 1st Prize, see SG51, pg.115), but the following technical features must be noted:

a) In the present PG, both the Pronkin Queens and the Ceriani/Frolkin Bishops are “Perfect Doublets”, in the sense that all thematic moves are precisely repeated (Pb7-b8Q, Qb8-b3, Qb3-d1, Pg4xBh5 for white and Pc2xQd1B, Bd1-h5 for black).

b) It was our intention to show the first example (as far as we know) of a "Perfect PG of the Future”, that is a TFPG which consists of Perfect Doublets (A)

Immun chess: A capture is only legal if the Circe rebirth square of the captured piece is empty (no rebirths though!)