No. 56, Oct-Dec 2011
R0185 - Andrey Frolkin
StrateGems, No. 56, Oct-Dec 2011
11+9. Last 8 single moves?
[b2Q3R/pk1ppppp/P2P4/1P1Kp2P/1N5P/7P/7P/8]
Solution
Retract: -1.a5-a6# Kb8xBb7 -2.Bc8-b7+ Kb7-b8+ -3.c7-c8B+ Kb6xBb7! -4.a4-a5+ Ka5-b6 (-3…Kb6xSb7? -4.a4-a5+ Ka5-b6 -5.Sc5-b7+?? is illegal check to the wK).
The black King uncaptures two white Bishops on the same square: a promoted Bishop and an original one. (A)
R0186 - Günther Weeth & Andrey Frolkin
13+12. Release the position
[NB3b1n/RPp1p1p1/r1p5/Qpp5/K5P1/4PP2/kPP1Pp2/2Rn4]
White balance: 13 (pieces on the board) + 3 (axb, bxc, dxc) = 16. Black balance: 12 (pieces on the board) + 4 (axb, f2xe3, g2xf3, hxg) = 16. If d2xe3, then either the white f-pawn, or the white/black h-pawn is unaccounted for. Therefore, d2-d8=X.
Retract: -1…b6-b5# -2.Rb1-c1 Sf7-h8 -3.Rc1-b1 Sd6-f7 -4.Rb1-c1 Sf5-d6 (-4…Sc4-d6 -5.Rc1-b1 Sa3-c4 -6.Rb1-c1: retro-opposition, -6.g3-g4? Sb1-a3 -7.?? or -5.Qd2-a5? Sa5-c4+ -6.Qd8-d2 - ??) -5.Rc1-b1 Sg3-f5 -6.Rb1-c1 Sh1-g3 -7.Rc1-b1 h2-h1S -8.g3-g4! (-8.Rb1-c1? h3-h2 -9.Rc1-b1 h4-h3 -10.h3xSg4 Se5-g4 -11.Rb1-c1 Sc4-e5 -12.Rc1-b1 Sa3-c4 -13.Rb1-c1: retro-opposition, -13…h5-h4 -14.Rc1-b1 Sb1-a3 -15.h2-h3 Ka1-a2. The retro-opposition seems to have been overcome, but…-16.Ka3-a4? Sc3-b1+ -17.?? is illegal check to the bK from wRc1, or -16.Kb3-a4?? is illegal check to the bK from wQa5) -8…h3-h2 -9.h2xSg3! Sf5-g3 (-9...Sf1-g3? -10.Rb1-c1 Sd2-f1 -11.Rc1-b1 Sb1-d2 -12.??) -10.Rb1-c1 Sd6-f5 -11.Rc1-b1 Sc4-d6 -12.Qd2-a5 Sa5-c4+ -13.Qd8-d2 h4-h3! -14.d7-d8Q h5-h4! -15.d6-d7 d7xBc6! -16.Kb5-a4! Sb3(c4)-a5 etc.
A “standard” attempt to overcome retro-opposition fails; the retro-cage has to be released in a way which allows avoiding retro-opposition altogether. (A)
R0187 - Nikolai Beluhov
12+15. Release the position
[4bRrq/p2p1Bp1/p4pK1/N1p2p1n/3P3P/1n2P1P1/kPPp2P1/1Rb5]
The bPd2 captured the wB by e3xBd2. The SW cage can be opened by unplaying the wB back to f1 and retracting e2-e3. This retraction must precede both the retractions of f2xg3 (so that the bK may exit), and h2(h3)-h4 (so that the wR may return home). Retract: -1...Sa1-b3 -2.Sc4-a5+ (The only way to avoid retro-stalemate. The two Knights need to get past each other on a narrow staircase) -2…Sb3-a1 -3.Sb6-c4 Sa5-b3 -4.Sd5-b6+ Sc4-a5 -5.Sc7(f4)-d5 Sb6-c4 -6.Se6-c7(f4)+ Sd5-b6 -7.Sf4-e6 Sc7-d5 -8.Sd5-f4+ Se6-c7 (The wS now goes all the way back in order to make way for the wB) -9.Sb6-d5 Sd8-e6 -10.Sc4-b6+ Se6-d8 -11.Sa5-c4 Sd8-e6 -12.Sb3-a5+ (at least 22 successive Knight moves preceded the diagram position) c6-c5 -13.Bc4-f7 Sf7-d8+ -14.Bf1-c4 c7-c6 -15.e2-e3 e3xBd2 -16.B~-d2 and the position unlocks.
R0188 - Nikolai Beluhov
Dedicated to Nikita Plaksin.
15+12. Did the black King ever return to his home square?
[bR3BBb/rR2pkP1/Pp3Ppp/1N1P1p2/2pK4/3P1N1P/6PQ/6nr]
The black King returned to e8, at least three times. Retract: -1.Bh7-g8+ Ke8xSf7 -2.Sd8-f7+ Kd7-e8 -3.Sc7-b5+ Kd6-d7 -4.Se5-f3+ Kd7-d6 -5.Sc6-e5+ Ke8-d7 -6.Sb5-c7+ Kf7-e8 -7.Se6-d8+ Ke8-f7 -8.Sd8-c6+ Kd7-e8 -9.Sc7-b5+ Kd6-d7 -10.Sf4-e6+ Kd7-d6.
The black King strolls up and down his path, the white Knights hopping about him until they re-arrange themselves so as not to trouble his walk. Disregarding repetition, the last 20 single moves are completely determined. (A)
P0315 - Kostas Prentos & Andrey Frolkin
15+14. a) PG 20 b) Undo black’s castling, then PG 19½
[1n1q1rk1/1pp1npp1/Bp1p4/2b3rP/5B1p/N2P1P2/1PP1QP1P/2KR2NR]
1.a4 h5 2.Ra3 h4 3.Rb3 Rh5 4.Rb6 axb6 5.g4 Raa5 6.gxh5 Rg5 7.a5 e5 8.a6 Bc5 9.a7 d6 10.a8R Bg4 11.Ra1 Bf3 12.exf3 e4 13.Ba6 e3 14.d3 e2 15.Bf4 Kf8 (15…Se7 16.Kd2 e1R 17.Sa3 Re6 18.Qe2 Rh6 19.Rd1 Rh8 20.Kc1 0-0??) 16.Kd2 e1R 17.Sa3 Re8 18.Qe2 Se7 19.Rd1 Kg8 20.Kc1 Rf8.
Double false castling with promoted Rooks (one being a Pronkin Rook, as well). The "false" try, ending with another Pronkin Rook on h8, fails because black cannot castle. (A)
P0316 - Nicolas Dupont
13+14. PG 21
[1r6/4npp1/1b2p1p1/pkn1p1P1/2p5/rb1P3N/1PPP1P2/RNB1KB1R]
1.a4 e5 2.a5 Bc5 3.a6 Bb6 4.axb7 Sa6 5.b8Q c5 6.Qd6 Bb7 7.Qg6 hxg6 8.g4 Rh3 9.g5 Ra3 10.h4 Bd5 11.h5 Bb3 12.h6 c4 13.h7 Sc5 14.h8Q a5 15.Qh3 Se7 16.Qe6 dxe6 17.Sh3 Qd3 18.exd3 Kd7 19.Qh5 Kc6 20.Qh8 Kb5 21.Qb8 Rxb8.
Two Ceriani-Frolkin Queens occur on b8 and h8. Then, the original Qd1 goes to h8 and b8 (double anti-Pronkin theme), to be captured (Phantom theme). The symbolized notation is therefore (AP & AP & PH)(Q). (A)
P0317 - Kostas Prentos & Andrey Frolkin
12+12. PG 21½
[1n1k3r/1p2n1p1/1p1q2p1/B4b2/R1B1rQ2/bP4P1/1P1N2P1/3K2NR]
1.d4 e5 2.d5 e4 3.d6 e3 4.dxc7 d5 5.Qd4 Bf5 6.Qf4 d4 7.c8S d3 8.Sb6 axb6 9.Bd2 Ra4 10.Ba5 dxc2 11.Sd2 c1S 12.Kd1 exf2 13.e4 Sb3 14.e5 Re4 15.Bc4 f1S 16.axb3 Sg3 17.Ra4 Ba3 18.e6 Qd6 19.exf7+ Kd8 20.f8S Se7 21.Sg6 hxg6 22.hxg3.
Four Ceriani-Frolkin Knights are produced by the four central pawns. Compare with P1107616 in PDB website: http://www.softdecc.de/pdb/index.pdb (A)
P0318 - Silvio Baier
14+14. PG 22
[2bq1b2/2p1p3/n1p3kn/1P6/6p1/rnr4r/2PPPPP1/RNBQKBNR]
1.h4 f5 2.h5 Kf7 3.h6 Kg6 4.hxg7 h5 5.Rh3 h4 6.Rb3 h3 7.a4 h2 8.a5 h1R 9.Ra4 R1h3 10.Rh4 Rc3 11.Rh1 Rhh3 12.a6 Sh6 13.axb7 a5 14.g8S a4 15.Sf6 a3 16.Sg4 a2 17.Ra3 a1S 18.b4 Sb3 19.Ra1 Ra3 20.b5 Sa6 21.b8S fxg4 22.Sc6 dxc6. CF(S,IP(S)) & SI(R,R) (A)
P0319 - Silvio Baier
14+14. PG 24
[2b2b2/2p1pk2/n3p1rn/1P6/q4Pp1/Bnr4r/2PPP1P1/RN1QKBNR]
1.h4 f5 2.h5 Kf7 3.h6 Qe8 4.hxg7 h5 5.Rh3 h4 6.Rb3 h3 7.a4 h2 8.a5 h1R 9.Ra4 R1h3 10.Rh4 Rc3 11.Rh1 Rhh3 12.a6 Sh6 13.axb7 a5 14.g8R Ra6 15.Rg4 Rg6 16.f4 Sa6 17.b8R a4 18.R8b6 a3 19.Re6 a2 20.Ra3 a1S 21.b4 Sb3 22.Ra1 dxe6 23.Ba3 Qa4 24.b5 fxg4.
CF(R,R) & SI(R,R) (A)
P0320 - Silvio Baier
14+14. PG 25
[r1b2b2/r2Pp3/n3p1kn/2p5/7q/2r1P1pr/1PP1KPP1/RNBQ1BNR]
1.h4 f5 2.h5 Kf7 3.h6 Kg6 4.hxg7 h5 5.Rh3 h4 6.Rb3 h3 7.a4 h2 8.a5 h1R 9.Ra4 R1h3 10.Rh4 Rc3 11.Rh1 Rhh3 12.a6 Sh6 13.axb7 a5 14.g8B a4 15.Be6 dxe6 16.e3 Qd4 17.Ke2 Qh4 18.d4 a3 19.d5 a2 20.d6 a1R 21.d7 R1a7 22.Ra3 Sa6 23.b8B c5 24.Bg3 f4 25.Ra1 fxg3.
CF(B,IP(B)) & SI(R,R) (A)
P0321 - Silvio Baier
14+14. PG 25½
[4rb2/r1p2p2/2n1pk1n/8/bP1p2P1/1Brq3r/2PPPP2/RNBQK1NR]
1.h4 e5 2.h5 Ke7 3.h6 Kf6 4.hxg7 h5 5.Rh3 h4 6.Rb3 h3 7.a4 h2 8.a5 h1R 9.Ra4 R1h3 10.Rh4 Rc3 11.Rh1 Rhh3 12.a6 Sh6 13.axb7 a5 14.g8Q a4 15.Qg4 a3 16.Qe6+ dxe6 17.g4 a2 18.Bg2 a1R 19.Bd5 R1a7 20.Ra3 Bd7 21.b4 Ba4 22.Bb3 Sc6 23.b8Q Qd3 24.Qb6 Re8 25.Qd4 exd4 26.Ra1.
CF(Q,IP(Q)) & SI(R,R) (A) !
P0322 - Satoshi Hashimoto
14+15. PG 25
[KnbqkbnQ/3p2pR/1prppp2/pB6/P1N4P/2rP2P1/1P2PP2/2B3N1]
1.a4 a5 2.Ra3 Ra6 3.Rh3 Rc6 4.Sa3 Rxc2 5.Sc4 Rc3 6.Qc2 Sf6 7.Qxh7 Rg8 8.Qh8 e6 9.Rh7 Be7 10.h4 Rf8 11.Rh3 Sg8 12.Rd3 f6 13.Rd6 Kf7 14.d3 Re8 15.Kd2 Bf8 16.Ke3 Qe7 17.Kd4 Rd8 18.Kc5 cxd6+ 19.Kb6 Ke8 20.Ka7 b6 21.g3 Ba6 22.Bg2 Rc8 23.Bc6 Qd8 24.Bb5 Rc6 25.Ka8 Bc8.
It takes six steps for the black Rook h8 to reach c6. Five black pieces step aside to let the Rook pass and then they return home.
