Jul-Aug 2006

R304c - Andrei Kornilov, Andrei Frolkin

Probleemblad May-June 2006

-1. Rg8xQg7 Qf8-g7 -2. Ng7-e8 Re8xNe7 -3. Nd5-e7 Re70d7 -4. Bd7-c8 b3-b2 -5. Bb5-d7 b4-b3 -6. Bf1-b5 b5-b4 -7. f3-f4 b6-b5 -8. e2xBf3.

R311 - Unto Heinonen

Probleemblad May-June 2006

1. g4 Nf6 2. g5 Ne4 3. g6 hxg6 4. Nf3 Rxh2 5. Ne5 Rh8 6. Nxd7 e5 7. a3 Bxa3 8. Bh3 Bb4 9. O-O Bxd2 10. Nxb8 Bf4 11. Qxd8+ Kxd8 12. Bxc8 Kxc8 13. Be3 Kxb8 14. Bb6 axb6 15. Rxa8+ Kxa8 16. Nc3 Rb8 17. Ra1#

The path of the black king is cleared by QxQ, BxB, NxN, RxR.

R312 - Thierry le Gleuher

Probleemblad May-June 2006

1. e3 h5 2. Qg4 hxg4 3. Nf3 gxf3 4. Be2 fxe2 5. Rf1 exf1=B 6. Nc3 Bc4 7. Na4 Be6 8. Nb6 axb6 9. b3 Ra5 10. Ba3 Rg5 11. Bc5 bxc5 12. a3 b5 13. a4 Bb7 14. a5 Be4 15. a6 c6 16. a7 Na6 17. f3 Qb8 18. f4 Kd8 19. f5 Kc7 20. f6 B4f5 21. e4 Kd6 22. e5+ Kxe5 23. h3 Kf4 24. h4 Kg3 25. h5 Kh2 26. h6 Kh1 27. h7 Nh6 28. b4 Rg8 29. O-O-O+

Four tempo moves (b2-b3-b4 isn't a tempo, because b2-b3-b4, Bc1-a3-c5 can't be done one move quicker) by white pawns.

R313 - Andrei Kornilov

Probleemblad May-June 2006

a) There are pieces on b2, b3, b4, c4, d1, d6, e4, e6, f3, f4, g1, g2, g3, g4, g5, g7, h1, h2, h3 b+c) If the orientation of the board is correct, then the officers are on d1, g1 and h1. The capture balance for the pawns is 14 captures, which is one too much. An identical argument rules out the 180 degree rotation. There are two options: the officers are on a1, b1, c1(I) or f8, g8, h8 (II).

I) The bishop is on b1. Capture balance shows that all missing pieces are captured by the pawns. The original a-, b- and c-pawns haven't captured, so a2=white, b2=white, a5=black, b7=black. Because of Bb1, c2=black, c3=white, c7=black. Because the c-bishops were captured, d2=black, d7-white. The black pawn on c2 arrived there after Ka1 and Bb1 arrived, so after Ra1 and Bc1 moved, and hence d2 moved. This implies that the original black d-pawn never captured, just like the white d-pawn. So d4=white, d6=black. This results in 4 visible black captures, so the missing black pawns are on the f- and g-file, so d3=white, e2=white. But this is impossible, because c2 could never have reached that square with the white d-pawn on d3.

II) The bishop is on g8. Capture balance shows that all missing pieces are captured by the pawns. The original f-, g- and h-pawns haven't captured, so g2=white, h4=white, g7=black, h7=black. Because of Bg8, f7=white, f6=black, f2=white. Because the f-bishops were captured, e2=black, e7=white. The remaining two white pawns captured 3 times, so they're either on the b- and d-file, or both on the c-file. The latter is impossible, because Bc8 would be unavailable for capture, so b7=white, d7=white, and the other pawns (c4, c5, e6) are black.

There's a dual now: the white king could be on either h8 or f8.