Nº33 Sergey Osintsev

Publicado el 29/04/2024 a 242 × 242 en 23th INTERNATIONAL INTERNET TOURNAMENT (UAPA) – 2024

Win

Section B.1.

Sergey Osintsev (Russia)

wKc3,Bc5,Rg3,Pc7/bKf4,Ne7,Ra1,Pe4

1.Rg8!
1.Rg7? Nd5+ 2.Kb2 Ra8=
1.Bd6+? Kf5 2.Bxe7 Rc1+ 3.Kd4 Rxc7–+

1…Rc1+
1…Nd5+ 2.Kb2+-

2.Kd4 Rd1+ 3.Kc4 Rc1+
additional line 3…Rd7 4.Kb5! Rxc7 5.Bd6+ Ke3 (5…Kf5 6.Rf8++-) 6.Rg3+ Kf2 7.Bxc7 Nd5 8.Bb8 (8.Bd6; 8.Be5) 8…e3 9.Rg5! a) 9.Rg8? e2 10.Bg3+ Kf3 11.Kc4 Position D1 with Rg8 – draw 11…Nf6! 12.Rg6 (12.Rg7 Nh5!= fork; 12.Rg5 Ne4!= fork) 12…Ng4! 13.Be1 Ne5+= fork; b) 9.Rg7? e2 10.Bg3+ Kf3 11.Kc4 Position D2 with Rg7 – draw 11…Ne3+ 12.Kd3 Nf5!= fork; c) 9.Rg6? e2 10.Bg3+ Kf3 11.Kc4 Position D3 with Rg6 – draw 11…Nf4! tempo! 12.Rg8 Ng2 13.Kd3 e1Q 14.Bxe1 Nxe1+=; d) 9.Kc4? e2 10.Ra3 Ne3+!=; 9…e2 10.Bg3+! Kf3 11.Kc4! Position D with Rg5 – win 11…Nf4 12.Be1 Ng2 13.Rg3++- A logical study within a study!

4.Kb5 Kf5 5.Rf8+! preliminary check!
try 5.Re8? Rb1+! 6.Ka6 Rc1 7.Kb5 Rb1+ 8.Ka4 Rc1 9.Kb5 Rb1+ positional draw 10.Bb4 Rxb4+! 11.Kxb4 Nd5+ 12.Kc5 Nxc7=

5…Ke6 6.Re8! pin 6…Kd5! 7.Rd8+
7.Rxe7? Rxc5+=

7…Ke6 8.Rd6+ main line A
8.Kb6? Rb1+=

8…Kf5!
main line B 8…Ke5 9.Rd1! Echo position C. Change thematic try and solution. (Thematic try 9.Rc6? Rb1+ (9…Nc8? 10.Bd4+! Kxd4 11.Rxc1+-) 10.Ka6 Nc8= Position A1 with Ke5 – not 11.Bd4) 9…Rxd1 a) 9…Rc2 10.Bxe7 Rxc7 11.Bd6++-; b) 9…Rc3? Position B with Ke5 – win 10.Bd4++- (10.Bxe7 Rxc7 11.Bd6++-) ; 10.Bxe7 Rc1 11.Bc5+-

9.Rc6! Change thematic try and solution.
loss of time 9.Rd5+?! Ke6 10.Rd6+ Kf5;
Thematic try 9.Rd1?! Rc3! Position B1 with Kf5 – draw (9…Rc2? 10.Rd5+! (10.Rd2? Rc3=) 10…Ke6 11.Rd6+ Ke5 (11…Kf5 12.Rc6 Nc8 13.Bd4+-) 12.Rd2!+- Echo position C1) 10.Rd5+ Ke6 11.Rd6+ Ke5! 12.Rd7 (12.Rd3?? Echo position C2 – defeat) 12…Nc8 13.Rd8 Ke6! 14.Kc6 (14.Rxc8 Kd7=) 14…Ne7+ 15.Kb6 Rb3+ 16.Ka6 Rc3! 17.Kb6 Rb3+=

9…Nc8
or 9…Rb1+ 10.Ka6 Nc8 Position A with Kf5 – there is 11.Bd4 11.Bd4! Ne7 12.Rf6++-

10.Bd4! Rd1
10…Nd6+!? 11.Kb6! (11.Rxd6? Rxc7=) 11…Nc8+ 12.Kb7 Rxc6 13.Kxc6 Ke6 14.Bc5+- 10…Rb1+ 11.Ka6! Rb3 12.Rf6+!+- (12.Rh6? e3! 13.Rh8 e2 14.Re8 Rb4! 15.Bf2 Nd6 16.Bg3 Re4 17.Rf8+ Kg5! 18.Rg8+ Kh5! 19.Rh8+ Kg5!=)

11.Rf6+!
loss of time 11.Kc5 Rc1+ 12.Kb5 Rd1

11…Kg5 12.Rf8! Nd6+ 13.Kc5+- Rxd4 14.Kxd4 Nb5+ 15.Kxe4 [15.Ke5+-] 15…Nxc7 16.Ke5+-