The Retrograde Analysis Corner
No. 89, Jan. 1998 - SOLUTIONS
7296 - Stanislav Vokál
a) White's rook was captured in the southwest corner. If black may still castle, white captured the two knights on e3 and h3, and the c-pawn couldn't have captured. So the c-pawn was captured on c2. But then the white queen couldn't have gotten out to get captured by the black pawn. So black can't castle (and white captured c2x[QR]d3, to let out the white queen)
b) Now white could've played c2-c3 to let out the queen (and the pawn on f5 comes from h7), so black may castle.
7297 - ?#8364;rpàd Molnàr
The last moves were: -1. .. f4xNg3 -2. Rh6-g6 g6xNf5 -3. Rh8-h6 h7xNg6 -4. Bh6-g5 g5xNf4 -5. Nf8-g6 g6-g5 -6. Ne6-f4 Kf4-g4 -7. Ng5-e6. White promoted four times (a-, b-, c- and d-pawn) to a knight on d8.
7298 - Henrik Juel (After Goldsteen)
Retroplay is: -1. .. Nh7-f8 -2. Be8xRf7 Rf8xNf7 -3. Ne5-f7 Rf7-f8 -4. Nc4-e5 Rf8xNf7 -5. Ne5-f7 Rf7-f8 -6. Na3-c4 Rf8xNf7 -7. Ng5-f7 Rf7-f8 -8. Nb5-a3 Rf8xNf7 -9. Nh6-f7 Rf7-f8 -10. Nc7-b5 Rf8xNf7 -11. Nb5xQc7 Qc8-c7 -12. Qd8-d7 Qc7xNc8 -13. Bd7-e8 Re8-f8 -14. Nh3-g5 Rf8-e8 -15. Ng5-f7 Rf7-f8 -16. Qf8-d8 Qd8-c7 -17. Be8-d7 Kc7-b8 -18. Na3-b5 Bb8-a7 -19. Na7-c8 Kc8-c7 -20. Nb5-a7 etc.
White captured Nb5xQc7 and Be8xRf7, and promoted to a knight on a8, c8, d8 and h8. Black captured a7xPb6, c6xRd5, d7xRc6, e7xBd6, h7xPg6, Qc7xNc8, and Rf8xNf7 five times.