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Die Schwalbe

No. 236, April 2009

14060 - Andrei Frolkin

Die Schwalbe 236, April 2009

Dedicated to D. Baibikov

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 - Klaus Wenda

Die Schwalbe 236, April 2009

Dedicated to G. Weeth

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 main plan 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 - Werner Keym

Die Schwalbe 236, April 2009

Dedicated to V. Liskovets

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 - Bernd Gräfrath

Die Schwalbe 236, April 2009

Dedicated to Cedric Lytton's 70th birthday

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 - Nicolas Dupont

Die Schwalbe 236, April 2009

Dedicated to Thierry le Gleuher

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 - Bernd Gräfrath

Die Schwalbe 236, April 2009

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 - Dragan Petrovic

Die Schwalbe 236, April 2009

-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.


14067 - Ravi Shankar

Die Schwalbe 236, April 2009

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.


14068 - Werner Keym, Bernd Schwarzkopf

Die Schwalbe 236, April 2009

In a legal position with 3 white pieces and the black king, the 6 distances between the pieces are all integer. The sum of the distance to the origin square of all pieces should be minimal.

a) White has 2 pawns
b) White has 1 pawn
c) White has 0 pawns

- - -

a) Ke1 Pe2 Pe3 - Ke8: Sum of distances to home squares is sqrt(2).

b) Ke1 Pe2 Qe3 - Ke8: Sum of distances to home squares is sqrt(5).

c) Try: Ke1 Be2 Qe3 - Ke8: sum of distances to home squares is sqrt(2)+sqrt(5) ~~ 3.6. But there is a better solution: Ke1 Sb1 Rh1 - Ke5 where the distance is 3.