The Retrograde Analysis Corner
No. 111, Oct. 1994 - SOLUTIONS
3193 - J. Lubkin
Add wKg5. But then 1. Bd4#?? fails. This move is illegal because Black is retropat and then has the move. Mate in 1 is by 0 ... b6/c5/e3 1. Nc6#/Bb8#/Rxe3#.
3194 - A. Zolotarev and N. Plaksin
Add a White Pawn h5. The position unlocks by retracting d7xc6. Last moves are: -1. Bc1xNb2+ Ne1-d3 -2. h4-h5 f2xNe1=N -3. Nd3-e1 f3-f2 -4. Nf2-d3 f4-f3 -5. Nd1-f2 Nd3-b2 -6. Nb2-d1+ Nb4-d3 -7. Bc4-a6 Na6-b4+ -8. Bg8-c4 f5-f4 -9. g7-g8=B f6-f5 -10. g6-g7 f7-f6 -11. f5xBg6 Bh5-f6 -12. f4-f5 Bg4-h5 -13. f3-f4 Bc8-g4 -14. Kb5-a5 d7xQc6 etc.
3195 - P. Wassong
The wBh8 requires wPc2xd3xe4xf5xg6xh7-h8=B, consuming all missing bl. units except black-squared bBf8. Then the bPa7 had to be promoted before it can be captured. So that a wP (a or b) had to be captured to open the way (and no 2nd wh. promotion is possible). The other missing wh. unit is a wN, captured by d7xNc6. bPh7 cannot have been promoted, so that it has been captured at home.
The S-E corner unlocks by (1) retracting wPg3-g4, then (2) extracting the bBh3, then (3) retracting bKh3-h2, then (4) inserting something on h2 and (5) retracting Rh1-g1. Then everything unlocks. But only a wN can reach h2 for step (4). This wN must be resurrected on c6, after bBc8 is driven back home (requiring that e7-e6 is taken back).
Now we see that the bK had to leave the 8th rank before d7xc6 or e7-e6 took place. He had to go through the h7 hole, when there was a promoted wBh8. Necessarily, the bKR was still there (so that the bQR has been captured) and it could only let the bK out if the first move of the bK was O-O. (The bR now on a8 is the original bKR, the bKB was captured at home, the wPa2 was captured on its file).
3196 - A. Kornilov and A. Frolkine
Last move is a check given by Qg5, coming from g3 and same colour as Kf4, thus same colour for Re3, Rf3, Re4, Nd3, Nd5, Bh2, Bb8. Pawn structure requires 2 captures, Rs and Bs require 2 promotions. Thus Pf2, g2, h6 are White, h7, g7, f6 Black. A White promotion on d8 would need too many captures, so that Black did promote on c1, into a B.
Finally, White Kf4, Qg5, Re4, Rf3, Rf5, Bb8, Bh2, Nd3, Nd5, Pb6, e3, e7, f2, h6; Black Kh5, Rf7, Rg8, Bf8, Bg6, Nh8, Pb5, b7, e6, f6, g7, h7. Last moves are -1. Qg3xBg5+ Bh4-g6+ -2. Re5xRf5+ Rg5-f5+.
István Vadai (Hungary, Szeged) found a cook:
I found an other legal coloring: White Kh5, Rf7, Rg8, Bf8, Bg6, Nh8, b5, b6, e6, e7, f2, g2, h6; Black Kf4, Qg5, Re4, Rf3, Rf5, Bb8, Bh2, Nd3, Nd5, b7, e3, f6, g7, h7. Last move is -1. Qg3xNg5+ and no more determined moves.
Proof game: 1. h2-h4, f7-f6 2. e2-e4, e7-e6 3. d2-d4, c7-c5 4. h4-h5, Bf8-d6 5. d4-d5, Ke8-e7 6. h5-h6, Bd6-h2 7. Bf1-e2, c5-c4 8. d5xe6, d7-d5 9. Be2-h5, d5-d4 10. Bh5-g6, Qd8-a5+ 11. Ke1-e2, Ke7-d6 12. c2-c3, Kd6-e5 13. Ke2-f3, Ng8-e7 14. Kf3-g4, Qa5xc3 15. Kg4-h5, a7-a5 16. Ng1-h3, Qc3-g3 17. Nh3-g5, c4-c3 18. b2-b3, Bc8-d7 19. a2-a4, Bd7-b5 20. a4xb5, c3-c2 21. Bc1-a3, Rh8-c8 22. Nb1-d2, Ke5-f4 23. Nd2-c4, Rc8-c5 24. Nc4-d6, Rc5-f5 25. Nd6-f7, c2-c1=R 26. Nf7-h8, Rc1-c3 27. Qd1-e1, Rc3-f3 28. Qe1-e3+, d4xe3 29. Ra1-c1, Ne7-d5 30. Rc1-c8, Nb8-a6 31. Rc8-g8, a5-a4 32. Ba3-f8, Na6-c5 33. Rh1-c1, Nc5-d3 34. Rc1-c7, a4-a3 35. Rc7-f7, a3-a2 36. e6-e7, Ra8-a4 37. e4-e5, Ra4-e4 38. e5-e6, a2-a1=B 39. b5-b6, Ba1-e5 40. b3-b4, Be5-b8 41. b4-b5, Qg3xg5++