Mar-Apr 2005
R303 - Paul Raican
Probleemblad Mar-Apr, 2006
1. f4 c6 2. f5 Qa5 3. f6 Qc3 4. bxc3 Kd8 5. Ba3 Kc7 6. Bd6+ Kb6 7. Na3 Na6 8. Qb1+ Nb4 9. Qb3 g6 10. Qe6 fxe6 11. f7 Bg7 12. f8=Q Bd4 13. Qxc8 Nf6 14. Qf8 Ne8 15. Qf3 Rf8 16. cxd4 Rf5 17. Qb3 Rb5 18. Qb1 Nd5 19. Qd1 Rb1 20. Nf3 Rc1 21. Nb1 Kb5
White queen Pronkin.
R304 - Andrei Kornilov, Andrei Frolkin
Cook by Dolf Wissmann: Retract -1... Re7xNf7 -2. Ng7-e8 Qe8-f8 -3. e3xNf4 N~ -4. Nf7-e5 and further e.g. -5. Rf8-g8 Kg8-h7 -6. Rf7-f8 Kh7-g8 -7. ~ Qg8-e8 -8. Rf8-f7 ~ -9. Ne8-g7 ~ -10. Bg7-h8 ~ -11. Rf7-f8 Kh8-h7 -12. Bf8-g7 ~ -13. Rg7-g6 g6-g5 etc.
R305 - Roberto Osorio
-1. Bf7xBg8. The extra bishop resulted from a promotion on d1 or f1, where the e-pawn promoted after 2 captures. So all missing white pieces are accounted for, which means black only has one retro-move: g5-g4 -2. g7xRh8 g6-g5 -3. NexNf8 Nd7-f8 -4. Qd8xQe8 and 1. Nc5 Nc5#
R306 - Klaus Wenda
Retract -1. Kh6xRh7[Ke1] Bf6-g7 -2. Bf8xBg7[Bc1] and 1. Qe1 Rh8/Bf8#