Gewidmet T. H. Willcocks
12+14. Löse die Stellung auf!
The position unlocks when black can retract a6xb5. For this, the white
knight from c7 needs to unpromote on a8, and the pawn should go back
to a5. This means that a black knight on c7 is needed to prevent a check
by the white bishop on b8. This means that the white king should go
to f8.
The retro-play is: -1. ... Nc8-a7 -2. Ba7-b8 Nb8-d7 -3. Na8-c7
Na6-b8 -4. Nc7-a8 Nb4-a6 -5. Na8-c7 Nc2-b4 -6. Nc7-a8 Ne2-c2 -7. Na8-c7
Ng4-e3 -8. Nc7-a8 Nh6-g4 -9. Na8-c7 Rg8-g7 -10. Nc7-a8 Rh8-g8 -11. Bb8-a7
Ng8-h6 -12. Ba7-b8 Bh6-f8 -13. Bb8-a7 Bg7-h6 -14. Ba7-b8 Bf8-g7 -15.
Na6-c7 Nh6-g8 -16. Nb4-a6 Ng4-h6 -17. Na2-b4 Ne3-g4 -18. Nc3-a2 Nc2-e3
-19. Nd1-c3 Nb4-c2 -20. Ne3-d1 Na6-b4 -21. Ng4-e3 Nb8-a6 -22. Nh6-g4
Nd7-b8 -23. Ng8-h6 Bh6-f8 -24. h3-h4 Nf8-d7 -25. Nh6-g8 Rg8-h8 -26.
Ng4-h6 Rh8-g8 -27. Ne3-g4 Bh6-g7 -28. Nc2-e3 Rg8-h8 -29. Nb4-c2 Rg7-g8
-30. Na6-b4 Nd7-f8 -31. Nc7-a6 Nb8-d7 -32. Kf8-e8 Na6-b8 -33. Na8-c7
Nc7-a6 -34. Bb8-a7 Na7-c8 -35. h2-h3 Nc8-a7 -36. a7-a8=N d4-d3 -37.
a6-a7 Na7-c8 -38. a5-a6 a6xBb5
and finally the position unlocks. Very surprising and hard to find
tempo-maneuver with the black bishop!
Solution by Henrik Juel
