WCCI 2016-18: Sergiy Didukh (UKR)

(1)
Sergiy Didukh
Jan Timman-65 JT
2017
3rd/4th Honourable Mention
- version -

1. Nf5+! Nxf5 1... Kxh5 2. Nxh4 +- 2. Rxf6+ with two variations, both ending by model mates in the centre by promoted minor pieces:

a) 2...Kg7! Black's plan is to sacrifice his pawn f7 for a stalemate on move 11! 3. Rxf7+ Kh6 4. Rf6+ 4. Rb6+? Nc6 4... Kg5 5. Rxf5+ Kxf5 6. Nd6+ Kg5 7. Ne4+ Kf5 8. Rc7! 8. Be6+? Kxe4 9. Bxg4 Qf1 10. Bxh3 Qf7 11. h6 Kf3 = 8... Nc6! 9. Rxc6 Qxc6 10. e8=B! 10. e8=Q? Qc2+! 11. Bxc2 stalemate. 10... Qc1 11. Bg6#

b) 2... Kg5 3. Rxf5+ Kxf5 4. Nd6+ Kg5 5. Ne4+ Kf5 6. Rc7! 6. Bd1? Kxe4 7. Bxg4 Qd2+ 8. Kxh3 Qc1! 9. Rb4+ Ke3 10. Bf5 Nd7 11. Rb1 Qc8 12. Rb8 Qxb8 13. Bxd7 Qh8 = 6... Qxc7 6... Nc6 7. Rxc6 Qxc6 8. e8=Q! Qxe8 9. Nd6+ +- 7. e8=N! 7. e8=Q? Kxe4 8. Qg8 Qd7 9. Qg5 Nc6 10. Bc2+ Kd5 11. Bf5 Nd4 = 7... Qc1 8. N8d6#

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(2)
Sergiy Didukh
Olympic tourney
2018
1st Prize

Logical try: 1. Rg8? Qxh7 2. Rxg7+ Qxg7+ 3. Kxg7 h4 4. Nxd4 Kg4! 5. f3+ Kg5 6. Ne6+ Kf5 7. Nd4+ Ke5 8. Nc6+ Kd5 9. Ne7+ Kc4! Black's foreplan. 9... Kc5? 10. Ng6 h3 11. Nxf4 h2 12. Nd3+! +- 10. d3+ 10. Nf5 h3 11. Nxd6+ Kd3! -+ 10... Kc5! 11. Ng6 11. Ng8 f5! -+ 11... h3 12. Nxf4 h2 -+

13.Nd3+ is impossible

1. Nc1!! White's foreplan. 1... Qc2 2. Rg8 Qxh7 3. Rxg7+ Qxg7+ 4. Kxg7 d3! 4... h4 5. Ne2 h3 (5... Kg4 6. Ng1 =) 6. Ng1! h2 7. Nf3+ +- 5. Nb3! 5. Nxd3? h4 6. f3 h3 7. Nf2 h2 8. a4 Kh4 9. a5 Kg3 10. Nh1+ Kg2 11. a6 Kxh1 12. a7 Kg2 13. a8=Q h1=Q -+ 5... h4 6. Nd4 Kg4! 7. f3+ Kg5! 7... Kg3 8. Nf5+ Kxf3 9. Nxh4+ Ke2 10. a4 = 8. Ne6+ Kf5 9. Nd4+ Ke5 10. Nc6+ Kd5 11. Ne7+ Kc4 11... Kc5 12. Ng6 h3 13. Nxf4 h2 14. Nxd3+ Kd4 15. Nf2 +-; 11... Ke6 12. Ng6 h3 13. Nxf4+ +- 12. Nf5! h3 13. Nxd6+

13...Kd3 is impossible

13... Kb4 14. Ne4 h2 15. Nf2 = Knight and King make similar manoeuvres to block d3 by an enemy pawn and not let each other on this square on move 13.

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(3)
Sergiy Didukh
10th WCCT
2016
9th/10th Place

White wins

1. Qa3! Before capturing the bishop wQ forces move d3 so as to open the a7-g1 diagonal and defend f2. But Black can thwart this plan. 1... Rb3! (1... d3 2. Qxa7 Rb1+ 3. Kh2 Qe1 4. Qe7+ Kg4 5. f3+ +-) 2. Qxb3 (2. Qe7+? Kg4 3. Qxf7 (3. Qd7 Rh3+ 4. gxh3+ Kf3 =) 3... Rb5! 4. Qg7+ Rg5 5. fxg5 Qc1+ 6. Kh2 Bb8+ 7. g3 Bxg3+ 8. Kg2 Qc6+ =) 2... d3

Logical try:
3. Nd4? Bxd4! 3... Kg4? 4. Nf3 Qc1+ 5. Kh2 Qxf4+ 6. g3 Qxf3 7. Qa4+ Kg5 8. Qxa7 Qd5 9. Qc7 Kf6 10. Nd7+ +- 4. Ng6+ fxg6 5. Qe6! Qd1+ 6. Kh2 Qg4 7. g3+ Kh5 8. Qd5+ Qf5 9. Qf3+ Qg4 10. Qh1! g5 11. f3 Qc8 12. f5

Qc2+ is possible

12... Qc2+! 13. Kh3 g4+ 14. fxg4+ Kg5 15. Qd5 Kf6! 16. Qxd4+ Ke7 =

Solution:
3. Nc5!! 3. Ng6+? fxg6 shows that Ne6 is an obstacle (Qe6 is impossible). 3... Bxc5 3... Qxf2 4. Qxd3 Qxc5 5. Qh3# 4. Ng6+! fxg6 5. Qe6! Qd1+ 5... Qxf4 6. g3+ +- fork-1 6. Kh2 Qg4 7. g3+ Kh5 8. Qd5+ Qf5 9. Qf3+ Qg4 10. Qh1! g5 11. f3 Qc8 11... Qe6 12. g4+ Kg6 13. f5+ +- fork-2 12. f5!

Qc2+ is impossible

12... g4 12... Qxf5 13. g4+ +- fork-3 13. Kg2+ Kg5 14. Qh4+ Kxf5 15. Qxg4+ +- Deep foresight. Solution and logical try begin with different N-sacrifices.

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(4)
Sergiy Didukh
e4e5, 100 Years Cup
2018

White wins

1. Qg5! with two main lines:

a) 1... Bf1+! anticritical move 2. Kg1 2. Kxf1? Qa6+ 3. Kg1 Bd4+ = 2... Bd4+ 3. Bf2 Bxf2+ 4. Kxf2 e3+

5. Ke1! Logical try: 5. Kxe3? Qg2 6. Nf8+ Kh8 7. Ng6+ Kg8 8. Ne7+ Kf8 9. Qh6+ Ke8 10. Qh8+ Kd7 11. Qc8+ Kd6 12. Nf5+ Kd5 13. Qd7+ Kc4 14. Qd3+ Bxd3! Bishop is on the right side of the critical square d3. 5... Qg2 6. Nf8+ Kh8 7. Ng6+! Kg8 8. Ne7+ Kf8 9. Qh6+ Ke8 10. Qh8+ Kd7 11. Qc8+ Kd6 12. Nf5+ Kd5

13. Nxe3+! +- That's why King didn't go to e3. White and black deep foresights with sacrifices (Bf1+! Ng6+!) and capture refusals.

b) 1... h3+ 2. Kg1 Bd4+ 3. Bf2 Bxf2+ 4. Kxf2 e3+ 5. Kxe3 Qg2 6. Nf8+ Kh8 7. Ng6+! Kg8 7... fxg6 8. Qh6+ Kg8 9. Qg7# The g-file is closed by Pg6. 8. Ne7+ Kf8 9. Qh6+ Ke8 10. Qh8+ Kd7 11. Qc8+ Kd6 12. Nf5+ Kd5 13. Qd7+ Kc4 14. Qd3#

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(5)
Sergiy Didukh
Shakhmatnaya kompozitsia
2016
3rd Prize
- version -

White wins

1. Nb4+ Ka5 2. Nc6+ Ka6! 3. b7 Be8+! Black's plan is to sacrifice his bishop and queen for stalemate. (3... Qxe4 4. b8=N#; 3... Be6+ 4. Ke8! Bf7+ 5. Kf8 +-) 4. Kc8 Bd7+ 5. Kxd7 (5. Kd8? Qh4+ 6. Ne7 Qh8+ 7. Kxd7 Qxb2 =) 5... Qd1+ 6. Rd2! (6. Kc7? Qd7+ 7. Kxd7 stalemate.) 6... Qxd2+ 7. Kc8 Domination and zz. White hasn't created any threat but d2 is the only safe square for the queen.}

mutual zugzwang

7... Qd6 (7... Qe3 8. Bd3+! Kb6 9. b8=Q+ Kxc6 10. Be4+! Kc5 (10... Qxe4 11. Qb7+ +-) 11. Qa7+ +-; 7... Qg5 8. Bd3+ Kb6 9. b8=Q+ Kxc6 10. Qc7+ Kd5 11. Qa5+ +-; 7... Qh6 8. Bd3+ Kb6 9. b8=Q+ Kxc6 10. Qb5+ Kd6 11. Qb6+ +-; 7... Qc3 8. Bd3+ Kb6 9. b8=Q+ Kxc6 10. Qc7+ +-) 8. Bd3+! Kb6 (8... Qxd3 9. Nb4+ +-) 9. b8=Q+ Kxc6 Black saved his Queen but not King. 10. Qb5# Mutual annihilations of pieces. Domination with multiple Q-skewers.

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(6)
Sergiy Didukh
A.Selivanov-50 JT
2017
2nd Prize

White wins

Logical try: 1. Ra8? Rxh7 2. Ra1 Ra7! 3. Re1 Ra4+! 4. Kg3 Ra1 5. Rxa1 b2 6. Re1 b1=Q 7. Rxb1 c2

8. Re1 c1=Q 9. Rxc1 stalemate

1. Rd8! 1. g6? Kxg1 2. Rf8 Re4+ 3. Kg3 Re3+ 4. Rf3 Rxf3+ 5. Kxf3 Kf1 = 1... Rxh7 2. Rd1 Rd7! 2... c2 3. Re1 b2 4. Nf3+ g1=Q+ 5. Rxg1# 3. Re1 Rd4+! 4. Kg3! Logical try: 4. Kh3? Rd1! 5. Rxd1 c2 6. Re1 c1=Q 7. Rxc1 b2 8. Rd1 b1=Q 9. Rxb1 stalemate.; 4. e4? Rxe4+ 5. Rxe4 Kxg1 6. Kg3 Kf1 -+; 4. Kh5? Kh2! 5. Nf3+ Kg3 6. Nxd4 Kf2 7. Nf3 c2 8. g6 b2 9. g7 c1=Q 10. g8=Q b1=Q = 4... Rd1 5. Rxd1 c2 6. Re1 c1=Q 7. Rxc1 b2

8. Rd1! Now d1 is not attacked by a pawn. 8... b1=Q 9. Nh3+! That's why King didn't go to h3. 9... Qxd1 10. Nf2+ Kg1 11. Nxd1 Kf1 12. Ne3+ +- The final combination is prepared by the right first R-move foreseeing Black's counterplay for stalemate.

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