1. Qh5+! The black king cannot be let to move to the 6th rank. Thematic try: 1. Qe6? Qf8+ 2. Kb7 Qg7+ 3. Kb8 Qg3+ 4. Kc8 Qc3+ 5. Kb7 Qg7+ perpetual check 1... Kg7 2. Qg5+ Kf7 2... Kh7 3. Qf6 +- 3. Qf5+ 3. Qd8? Kg6! 4. Qb8 Qe4+ = 3... Kg7 3... Ke7 4. Qc8 Kf6 5. Qb7 Qf8+ 6. Qb8 +- because there is no Qf3+ 4. Qe6! Back to the main plan. The threat is Qc6 followed by Qb7+. 4... Qb5 4... Qf8+ 5. Kb7 = Unlike in the thematic try, now there is no Qg7+. 5. Qd6 Kf7 5... Kh7 6. Qf6! zugzwang (6. Qb8? Qc5! 7. Qb1+ Kh6 8. Kb7 Qe7+ 9. Ka6 Qa3+ perpetual check) 6... Qb4 7. Qc6 +- 6. Qb8 Qc4! 7. Qb7+ Kg8!
This is the ideal position for the black pieces. This position was reached (with reversed colours) by Averbach in the analysis of the game Schlechter - Pillsbury (Vienna, 1898). He couldn't prove the win, but later a winning method was discovered by Stalyoraitis (1980). I could prove that the method is unique in the sense that reaching Position B is essential to win.* The game Veselovsky - Bebchuk (USSR, 1977) also could have been decided by this, but it has ended in a draw. A flawed analysis of that game appeared in Benko's Laboratory (Chess Life, April, 1982). being my starting point to create this study. 8. Qd7! The shortest way to win. The other moves are time-waisting duals which all lead to the same key position. 8... Qe4+! 9. Kb8! Qf4+ 10. Kc8 Qc4+ 11. Kd8 Qh4+ 12. Qe7 Qd4+ 13. Kc8 Qc4+ 14. Kb8 Qb5+ The black queen cannot stay any longer on the 4th rank. 15. Qb7 Qe5+ 16. Ka8! Qc5
Unfortunately for black, the ideal position of its pieces couldn't be reached anymore. The black queen is on c5 instead of c4, and that allows the following check: 17. Qb3+! 17. Qd7?! Qf8+ The position is still a win but white has to work hard to reach again the key position (B). A similar check will not be available at the end of the main line because the black king will be on f8. 17... Kf8 The best chance is to stay on the 8th rank because there is no time to run with the king to the lower half of the board. 17... Kh8 18. Qh3+ (18. Qb7? Qc3! = mutual zugzwang) 18... Kg8 19. Qe6+ Kh8 20. Qe8+ Kg7 21. Qd7+ Kh8 22. Qd8+ Kh7 23. Kb7 +- 18. Kb7 Qe7+ 19. Ka6 Qd6+ 20. Qb6 Qd3+ 21. Kb7 Qd7+ 22. Ka8! Qd5+ 23. Kb8 Qe5+ 24. Kb7 Qe4+ 25. Qc6 Qe7+ 26. Kb8 26. Ka8?! Qd8+ 26... Qb4+ 27. Ka8! and black quickly loses because there is no check on the 8th rank. For example: 27... Qf4 27... Qb3 28. Qc8+ Kf7 29. Qb7+ +- 28. Qc8+ Kg7 29. Qb7+ Kh6 30. Qc6+ Kh5 With the black king on the 4th rank, the position would be draw. 31. Kb7 Qb4+ 32. Ka6 Qa3+ 33. Kb6 Qb3+ 33... Qe3+ 34. Qc5+ +- 34. Qb5+ and wins.
*Proving that Position B is essential for the winning process was done using the Haworth Method. In the normal QP v Q tablebase both positions are wins. By regenerating the tablebase from scratch with a 'seed' (Position B set a priori to DRAW), one can see if that causes a change of the evaluation for Position A as well (to DRAW) proving that the two positions depend on each other.
Watch this study on a dynamic board! Click here!
You can analyze the study with the help of the Syzygy tablebases here.
Update
The following study also features Stalyoraitis' position.
1. Qe8+ Kg7 2. Qd7+ Kg6 3. Qd3+ Kg7 4. Qg3+ Kf8 5. Qb8+ Kg7 6. Qc7+ Kg6 7. Qc4 Qf3+ 8. Kh2 Qe3 9. Qf1 Qe5+ 10. Kh1 Qh8+ 11. Kg2 Qa8+ 12. Kg1 Qa7+
13. Kh1! Qd7 14. Qf2 Kh5 15. Qe2+ Kg6 16. Qe4+ Kh5 17. Qc4 Qa7 18. Qe2+ Kg5 19. Kg2 Qd4
20. Qf2 Qe4+ 21. Qf3 Qd4 22. Qe2! We are back to the same position but with BTM. 22...Kg6 23. Qb5 Qe3 24. Kf1 Qe4 25. Kf2 Qd4+ 26. Kf3 Kh6 27. Qc6+ Kg7 28. Qc7+ Kg6 29. Qg3+ Kf5 30. Qh3+ Kg5 31. Qe6 Qd1+ 32. Qe2 Qd5+ 33. Kf2 Qf5+ 34. Kg1 Qb1+ 35. Kg2 Qg6 36. Qc4 Qf6 37. Qd3 Kh6 38. Qb5 Qg7+ 39. Kf2 Qa7+ 40. Ke2 Qd4 41. Kf3 Qf6+ 42. Ke4 Qe6+ 43. Kd4 Qd6+ 44. Kc4 Kg6 45. Kb3 Kg7 46. Ka4 Kh8 47. Qb2+ Kg8 48. Ka5 Qc5+ 49. Qb5 Qc7+ 50. Qb6 Qe5+ 51. Kb4 Qb2+ 52. Kc5 Qf2+ 53. Kc6 Qf3+ 54. Kc7 Qf7+ 55. Kb8 Qe8+ 56. Kb7 Qf7+ 57. Qc7 Qb3+ 58. Ka7 Qe3+ 59. Qb6 Qc3 60. Kb7 Qf3+ 61. Qc6 Qf7+ 62. Kb8 Qf4+ 63. Qc7 Qb4+ 64. Qb7 Qf4+ 65. Ka8 Qc4 66. a7 Kh8 67. Qb2+ Kg8 68. Qb6 Qe4+ 69. Qb7 Qc4
70. Qd7 Qe4+ 71. Kb8 Qf4+ 72. Kc8 Qc4+ 73. Kd8 Qh4+ 74. Qe7 Qd4+ 75. Kc8 Qc4+ 76. Kb8 Qb5+ 77. Qb7 Qe5+ 78. Ka8 Qc5 79. Qb3+ Kf8 80. Kb7 Qe7+ 81. Ka6 Qd6+ 82. Qb6 Qd3+ 83. Kb7 Qd7+ 84. Ka8 Qd5+ 85. Kb8 Qe5+ 86. Kb7 Qe4+ 87. Qc6 Qe7+ 88. Kb8 Qe5+ 89. Ka8 +-
If the above study is correct, then following study published in the SEE Manual becomes even cooler:
The starting position is a cyclic zugzwang. In order to win, white has to reach the same position but with black to move. There is a 4-move-long cycle to pass the move which is the only way to win! 1. Qg2+ Kf6 2. Qb2+ Kf5 3. Qb1+ Kg5 4. Qf1! Black is to move! 4... Qe8+ 5. Kf2 Qf8+ 6. Kg2 Qa8+ 7. Kg1 Qa7+ We have seen this position in Krug's study! 8. Kh1! The solution given in the SEE Manual stops here. 8... Qd7 9. Qf2 Kh5 10. Qe2+ Kg6 11. Qe4+ Kh5 12. Qc4 Qa7 13. Qe2+ Kg5 14. Kg2 Qd4
In order to win, white again has to reach the same position but with black to move. There is a 3-move-long cycle to pass the move. 15. Qf2 Qe4+ 16. Qf3 Qd4 17. Qe2! Black is in zugzwang! Etc.
2 comments:
I have just such a position in one of my studies. It's a very old study. Please have a look at the Harold van der Heijden database.
The starting position is of course different. But the key position is the same.
Thanks, Peter! I have found it, and I will post it here.
Post a Comment