[Retros] Solutions Die Schwalbe Heft 236

[Joost de Heer]

14060 - Frolkin
White pawns captured four times, black pawns twice, so the black h-pawn 
promoted without capturing.
Retro: -1. Sb8-d7# Bh4-g3 [Check avoidance #1] -2. b2xQa3 Qh3-a3 -3. 
e3-e4 Qc8-h3 [Check avoidance #2] -4. Sd7-b8 Qb8-c8 -5. Sc5-d7 Qc8-b8 
-6. Se4-c5 Bg3-h4 -7. Sd6-e4 Qg4-c8 -8. Sc8-d6+ Bh4-g3 [Check avoidance 
#3] -9. Rb8-a8 Qh3-g4 -10. Ra8-b8 Qh1-h3 -11. Rb8-a8 h2-h1=Q -12. Ra8-b8 
h3-h2 -13. Rb8-a8 Bg3-h4 -14. Ra8-b8 h4-h3 -15. Rb8-a8 h5-h4 -16. Ra8-b8 
h6-h5 -17. h5x(S|Q)g6 etc

*14061 - Wenda
To avoid a cook, the condition is changed to 'Anticirce Cheylan'.
-1. Ke1-f2? illegal!
-1. g2xSh3[Ph2]! Sf4-h3? -2. Ke1-f2 Qh8-h1 -3. Kb1xBb2[Ke1] Qg8-h8 -4. 
Ka1-b1 Qh8-g8 -5. b5xPa6ep[Pa2] a7-a5 -6. Kb1-a1 Qg8-h8 -7. Ka1-b1 
Qh8-g8 -8. Kb1-a1 Qg8-h8 -9. Ka1-b1 Ba2xSb1[Bc8]/a2xSb1=B[Bc8] (Forced 
to avoid triple repetition, a knight must be uncaptured because it's the 
only piece that can explain the check by the white queen) -10. 
Sb8xPd7[Sb1] Qh8-g8 -11. Be7-c5 & 1. Sa6#
-1. g2xSh3[Ph2]! Sg1-h3!! Now the mainplan doesn't work, because c7 
isn't guarded anymore. So a new pendulum is created to remove Sg1: -2. 
b5xPa6ep[Pa2] a7-a5 -3. Kf3-f2 Sh3-g1 -4. Kf2-f3 Sg1-h3 -5. Kf3-f2 
Sh3-g1 -6. Kf2-f3 Sf4-h3 (Forced to avoid triple repetition). And now 
the mainplan with a slight modification: -7. Ke1-f2 Qh8-h1 -8. 
Kb1xBb2[Ke1] Qg8-h8 -9. Ka1-b1 Qh8-g8 -10. f5xPe6ep[Pe2] e7-e5 -11. 
Kb1-a1 Qg8-h8 -12. Ka1-b1 Qh8-g8 -13. Kb1-a1 Qg8-h8 -14. Ka1-b1 
Ba2xSb1[Bc8]/a2xSb1=B[Bc8] (Forced to avoid triple repetition, a knight 
must be uncaptured because it's the only piece that can explain the 
check by the white queen) -15. Sb8xPd7[Sb1] (must be a pawn, other 
pieces can interfere on the queen line, or block d1 in the forward play) 
Qh8-g8 -16. Bb6-c5 & 1. Sa6#

Further tries:
-8. Kb1xRb2[Ke1]? .. -14... a2xSb1=B[Bc8]! -15. Sb8xBd7[Sb1] (must be a 
bishop because the missing pawns are needed for the promoted knight and 
rook) ... 1. Sa6 Bc8!
-10. d5xPe6[Pe2]? -14... Ba2xSb1=B[Bc8]! ... 1. Sa6 Bxd5[Bc8]!

14062 - Keym
There are three cases:
- Only wOOO and bOO are allowed (#3 with 1. Rf1!)
- Only wOO and bOOO are allowed (#3 with 1. Rd1!)
- No white castling, both black castlings are allowed. No mate in 3.

14063 - Gräfrath
1. e3 d5 2. Bc4 d4 3. Bd5 Qxd5 4. Nf3 Qxf3 5. O-O Qxd1 6. f3 Qxc1 7. Kf2 
Qxb1 8. Ke2 Qxa2 9. Rae1 e6 10. Kd1 Bd6 11. Kc1 Ne7 12. Rd1 O-O

White has castled... kingside!

14064 - Dupont
1. a4 c5 2. a5 Qb6 3. axb6 a5 4. h4 a4 5. h5 a3 6. h6 a2 7. hxg7 h5 8. 
Na3 h4 9. Rb1 a1=N 10. b4 Nb3 11. cxb3 h3 12. Nc2 h2 13. Na1 Rh3 14. Qc2 
Rf3 15. exf3 c4 16. Ke2 c3 17. Kd3 cxd2 18. Qc5 d1=B 19. Bf4 d5 20. Bg3 
d4 21. Ke4 d3 22. f4 Bf3+ 23. gxf3 d2 24. Ne2 d1=Q 25. Rg1 h1=R 26. Bg2 
Rh8 27. Bh1 Qd8
AUW: Queen and rook Pronkin, bishop and knight Ceriani-Frolkin.

14065 - Gräfrath
1. e4 Na6 2. Bxa6 Nf6 3. Bc4 Nh5 4. Qxh5 g5 5. Ne2 Bh6 6. Qxh6 Rf8 7. 
Bxf7+ Kxf7 8. Qh5+ Kg8 9. O-O
Black pseudo-castling.

14066 - Petrovic
-1. Se7*Sg8 a7-a6 -2. Bc8xSd7[Sg8] Sb8-d7 -3. Bd7*Bc8 Sa6-b8 -4. 
g2xBh3[Bc8] Sb8-a6 -5. Sc8xSe7[Sb8] Sg8-e7 -6. Se7-c8 Sf3xPg5[Pg2] -7. 
Bc8xSd7[Sg8] Sb8-d7 -8. Bd7-c8 [Now the white bishop and knight keep on 
uncapturing the knight, which oscillates between b8 and g8, while black 
prepares the retraction of g2xSh3] Bf1xPh3[Ph2] -9. Sc8xSe7[Sb8] Sg8-e7 
-10. Se7-c8 Se1-f3 -11. Bc8xSd7[Sg8] Sb8-d7 -12. Bd7-c8 Sc2-e1 -13. 
Sc8xSe7[Sb8] Sg8-e7 -14. Se7-c8 Sb4-c2 -15. Bc8xSd7[Sg8] Sb8-d7 -16. 
Bd7-c8 Sa6-b4 -17. Sc8xSe7[Sg8] Sg8-e7 -18. Se7-c8 Sb8-a6 -19. 
g2xSh3[Sg8] (and from now on, only the relevant uncapturing moves are 
given): -27... Sf1xPg3[Pg2] -36. f2xSg3[Sb8] -44... Se1xPf3[Pf2] -51. 
e2xSf3[Sg8] -59... Sc2xPe3[Pe2] -64. d2xSe3[Sb8] -66... Bc4xPd3[Pd2] 
-75. c2xSd3[Sg8] -77... Ba6xPc4[Pc2] -78. b3xSc4[Sg8] -79. a2xPb3[Pb7] 
and the position is finally released.

*14077 - Shankar
Intention: -1. Sd7-f8 OOO -2. Kh8-g8! [tempo] d4-d3 -3. Kg7-h8 d5-d4 -4. 
Kf6-g7 d6-d5 -5. Sb8-d7 d7-d6 -6. b7-b8=S and 1. ba8=Q/R#
But b7-b8=S is an illegal retraction, as black has no last move.

Mario Richter proposes to add a black pawn on g6 as correction, since 
black can't take back -2... g7-g6 because it'd trap the king.

14078 - Keym
a) Ke1 Pe2 Pe3 - Ke8: Sum of distances to homesquares is sqrt(2).
b) Ke1 Pe2 Qe3 - Ke8: Sum of distances to homesquares is sqrt(5).
c) Try: Ke1 Be2 Qe3 - Ke8: sum of distances to homesquares is 
sqrt(2)+sqrt(5) ~~ 3.6. But there is a better solution: Ke1 Sb1 Rh1 - 
Ke5 where the distance is 3.