# diagrammes

No. 119 , Oct. 1996 SOLUTIONS

3629 - Rodolphe Lebely

White captures are b5xa6, axbxc, [d/f]xe, and [f/h]xg. Black's last move was with either the pawn on d5 or the one on f5. Suppose it was c6xd5. The only missing white piece is a pawn. So black either captured a pawn on d5, or the d-pawn promoted (without captures), and black captured a piece on d5. In both cases, the black d-pawn couldn't have gotten off its own line. But none of the captures by white was on the d-line. The same reasoning, but then for the f-line, goes for g6xf5. So black's last move was either d7-d5, or f7-f5. Depending on which last move black did, #2 with 1. cd6 Rd6 2. Bd6# or 1. gf6 Rf6 2. Qf6#.

3630 - Leonid Borodatov

Visible black captures were bxc and exd. So the a-pawn didn't capture, which means that white's a- and b-pawn cross-captured, and the original a-pawn promoted. The d-pawn didn't capture either, so white needs two extra captures (dxe and exd, or dxc and cxd) to get the white pawn to d5. Together with fxe and gxf, this means 6 white captures. So the h-pawn captured to get promoted on g1, as did the g-pawn. So black has no last move. What was white's last move? It couldn't have been g4xf5, because the black g-pawn promoted after that capture. The only move that gives black retro-moves is e2-e4, and before that the moves were e4xNd3 Ne1-d3 Re3-c3. So black may capture en-passant.

So mate in 3 with 1. .. fe3! 2. Ke1 c1=[Q/R] 3. Bd1/Bc1 {Q/R}d1/Rc1#, and not mate in 1 with 1. Qa5?/Qb4?/Qb5?/Qc6?/Ra5?.

3631 - Thierry Le Gleuher

1. Nf3 d5 2. Ne5 Be6 3. Nc4 dc4 4. h4 Qd4 5. Rh3 Nd7 6. Rb3 cb3 7. a3! Bc4 8. Ra2 ba2 9. a4 ab1=N 10. a5 Nc3 11. a6 Nd1 12. ab7 Ne3 13. b8=B Nf5 14. Kd1 Nh4 15. Ke1 f5 16. Kd1 Kf7 17. Ke1 Kg6 18. Kd1 Kh5 19. Ke1 g6 20. Kd1 Bg7 21. Ke1 Be5 22. Kd1 Ngf6 23. Ke1 Rd8 24. Kd1 Nf8 25. Ke1 Rd5 26. Kd1 Ra5 27. Ke1 Qc5 28. Kd1

3632 - N. Plaksin and A. Zolotarev

3633 - Eric Angelini

3634 - Jean-Michel Trillon

1. g5 Rg8 2. g6 Rg6[+wPg2] 3. g4 Rf6 4. g5 Rh6 5. gh6[+bRh8] Rh6[+wPh2] 6. h4 Rh4[+wPh2] 7. h3 Rg4 8. hg4[+bRa8]