|Jul-12-19|| ||NBZ: White can just play the moves he is clearly itching to play here:|
22. Rxh7 Kxh7
23. Rh1+ Kg8 (Kg7 Bxe5+ and Qh6+ wins)
24. Rxh8+! Kxh8
25. Bxe5+ Rxe5
26. Qh6+ Kg8
I worried about this for a long time until I saw 27. f6. I was considering 27. Nd5 for a long time but simply 27. ... Rxd5 refutes it, and now it is too late for 28. f6 on account of 28. ... Rd1+ 29. Kxd1 Qd4+ and 30. ... Qxf6 winning.
|Jul-12-19|| ||NBZ: <al wazir>: 24. ... Kg7 can be met with 25. Bxe5+ fxe5 26. Qh6+ Kf6 27. Nd5#|
|Jul-12-19|| ||al wazir: <NBZ: 24. ... Kg7 can be met with 25. Bxe5+ fxe5>. No, black plays 25...Rxe5.|
The winning line is 25. f6+. If 25...Kxf6, then white plays 26. Nd5+. After 25...Kxh8, 26. Qh2+ wins.
That's why I deleted my post.
|Jul-12-19|| ||dragonfish1803: Instead of meekly acquiescing in white's combination why not try to throw a spanner in the works with 22....,Nd3+ ?|
|Jul-12-19|| ||NBZ: <al wazir> 24. ... Kg7 25. Bxe5+ Rxe5 26. Rxa8 is also winning. But yes, as you said, 25. f6+ is stronger.|
|Jul-12-19|| ||patzer2: For today's Friday puzzle, I got the first two moves 22. Rxh7! Kxh7 23. Rh1+. |
However, after 23...Kg8, I missed the strong follow-up 24. Rxh8+! +- (mate-in-7, Stockfish 10):
( [Stockfish 10 64] 82:M7 24...Kxh8 25.Bxe5+ Kg8 26.Qh6 Qa3+ 27.Kb1 Qc1+ 28.Kxc1 f6 29.Qxg6+ Kf8 30.Qxf6+ Kg8 31.Qg7# )
( [Stockfish 10 64] 82:M6 24...Kg7 25.f6+ Kxh8 26.Qh2+ Kg8 27.Qh6 Qa3+ 28.Kd1 Qc1+ 29.Bxc1 Nxf3 30.Qg7# )>
Instead, I went for 24. Qh2 +- (+6.41 @ 31 ply, Stockfish 10) which also wins but with more difficulty:
( [Stockfish 10 64] 31:+6.41 24...Nd3+ 25.Kb1 Qxc3 26.Qh7+ Kf8 27.Bxd6+ Re7 28.Qxh8+ Qxh8 29.Rxh8+ Kg7 30.Rxa8 Rd7 31.Bf8+ Kf6 32.fxg6 +-)
25.f6! Bxf6 26.Nd5 Qb5 27.Nxf6+ Kg7 28.Nd5 +- (M11, Stockfish 10 @ 50 ply)>
P.S.: So where did Black go wrong? Black's game took a turn for the worse with 19...Ne5? 20. Qd2 +- (+3.12 @ 31 ply, Stockfish 10).
Instead, 19...Qb4 20. Nd1 Bxf5 21. Qxc4 Qxc4 = (-0.04 @ 31 ply, Stockfish 10) would have given Black a level position.
|Jul-12-19|| ||TheaN: The theme of today's puzzle is to create the queen & pawn mating net (it probably has a name but I forgot) with the gaping hole on g7.|
White starts the demolish with <22.Rxh7!>. Black can't accept this but for sake of narrative I'm considering it one of the main lines. Mind that Black can freely (and probably should) first play Qa3 if he intends to accept the sacrifice as that removes a potential royal fork on d5: <22....Qa3+ 23.Kb1 Kxh7 24.Rh1+>
A) 24....Kg7 25.f6+! Kg8 (Kf8 26.Rxh8#; Kxf6 26.Nd5+ Kg7 27.Bxe5+ with Qg7# soon) 26.Rxh8+ Kxh8 27.Bxe5/Qh2+ with Qg7# soon.
B) 24....Kg8 25.Rxh8+ Kg7 (Kxh8 26.Bxe5+ Rxe5 27.Qh6+ Kg8 28.f6 with Qg7# soon) 26.Bxe5+ Rxe5 (f6 27.Qh6+ Kf7 28.Qh7#; dxe5 27.Qh6+ Kf6 28.Nd5#) 27.Qh6+ Kf6 28.Rxa8 +- should be enough. If Black kept the queen on b4 by playing 22....Kxh7 straight away, 28....Qxc3 doesn't work due to 29.Qh4+ g5 (Kg7 30.Qh8#) 30.Qh8+ Ke7 31.Qd8#.
So, alternatives? Yes, actually. Black can greatly muddy the waters with <22....Nd3+!> and White's combo is defused. After 23.cxd3? Kxh7! the combo falls apart almost entirely. No, <23.Qxd3 Qxc3 24.Rfh1! +-> and White keeps the pressure up. This is however, playable on the short term.
|Jul-12-19|| ||dragonfish1803: After 22....Nd3+;23.Qxd3,Qxc3;24.Rfh1,Bd4
Black is still fighting although I'd rather play the White side !
|Jul-12-19|| ||mel gibson: Fairly easy.
I saw that quickly.
Stockfish 10 agrees with the first move of the text:
(22. Rxh7 (♖h3xh7 ♘e5-d3+ ♕d2xd3 ♕b4xc3 ♖f1-h1
♗h8-g7 ♖h7xg7+ ♕c3xg7 ♔c1-b1 ♖a8-d8 f5xg6 ♕g7-d4 ♕d3-b5 ♖e8-e7 ♗f4-g5
♖d8-d7 ♗g5xe7 ♖d7xe7 ♕b5-a5 b7-b6 ♕a5-a6 ♖e7-c7 g6xf7+ ♔g8-f8 ♕a6-b5 ♖c7xf7
♕b5-c6 ♕d4-f6 ♕c6-a8+ ♔f8-e7 ♕a8xa7+ ♔e7-e6 ♕a7-a8 ♔e6-e7 ♕a8-b7+ ♔e7-e6
♕b7-c6 ♔e6-e7 ♖h1-d1 ♖f7-g7 ♕c6xb6 ♖g7-g6 ♕b6-c7+ ♔e7-e8 f3-f4 ♕f6xf4
♖d1-h1 ♖g6-h6 ♖h1-g1 ♖h6-f6) +5.25/39 312)
score for White +5.25 depth 39.
Black blundered by taking the Rook.
22. .. Kxh7
23. Rh1+ (23. Rh1+
(♖f1-h1+ ♔h7-g7 f5-f6+ ♔g7xf6 ♕d2xd6+ ♔f6-g7 ♗f4xe5+ ♖e8xe5 ♕d6xe5+ f7-f6
♕e5-e7+ ♔g7-g8 ♖h1-h6 ♕b4-a3+ ♔c1-b1 ♗h8-g7 ♖h6xg6 ♕a3-b2+ ♔b1xb2 ♔g8-h7
♕e7xg7+) +M11/65 79)
mate in 11.
|Jul-12-19|| ||whiteshark: |
click for larger view
Black to move
1) +2.37 (29 ply) 22...Nd3+ 23.Qxd3 Qxc3 24.Rfh1 Bg7 25.Qxc3 Bxc3 26.fxg6 fxg6 27.Bxd6 Bg7 28.Bxc5 Rac8 29.Ba3 Rc7 30.R7h3 Kf7 31.R3h2 Rd7 32.Rh7 Ke6 33.Kb1 Be5 34.Rxd7 Kxd7 35.Rg1 Re6 36.Bb2 Kd6 37.Rg5 Bxb2 38.Kxb2 Kc7
2) +3.65 (29 ply) 22...Qd4 23.Rfh1 Qxd2+ 24.Bxd2 Bg7 25.R7h3 Nd7 26.Nd5 Rab8 27.Bg5 Re5 28.Rg3 Rbe8 29.Bf4 Rxd5 30.exd5 Ne5 31.fxg6 Nxg6 32.Bxd6 Rd8 33.Bxc5 b6 34.Bb4 Rxd5 35.c4 Rd8 36.Rd1 Rc8 37.Kb1 a5 38.Ba3 a4 39.Kc2 axb3+ 40.axb3 b5 41.c5 Ne5 42.Rd5 Ng6
3) +7.79 (28 ply) 22...Bf6 23.Rfh1 Nd3+ 24.Qxd3 Qxc3 25.fxg6 Re7 26.Qxc3 Bxc3 27.Bxd6 Rc8 28.Bxe7 fxg6 29.Bd6 Bg7 30.e5 Re8 31.Bxc5 a6 32.f4 b5 33.Bd6 a5 34.c3 Re6 35.Kb2 Re8 36.Kc2 Re6 37.f5 gxf5 38.R7h5 Bxe5 39.Rg1+ Kf7 40.Rxf5+ Rf6 41.Rxe5 Rxd6 42.Rxb5 Re6 43.Rf5+ Rf6
6.0 minute analysis by Stockfish 9 v010218
|Jul-12-19|| ||agb2002: White is one pawn down.
Black has Nd3+ and Nc4.
The natural move is 22.Rxh7:
A) 22... Kxh7 23.Qh2+
A.1) 23... Kg8 24.Rh1
A.1.a) 24... Qxc3 25.Qxh8#.
A.1.b) 24... Bg7 25.Qh7+ Kf8 26.f6 Qa3+ (26... Bxf6 27.Bh6+ Ke7 28.Nd5+ and 29.Nxb4 wins decisive material; 26... Nd3+ 27.Kb1 also wins) 27.Kb1 Bxf6 28.Nd5 Red8 (28... Bg7 29.Bh6 Bxh6 30.Qh8#) 29.Bh6+ Ke8 30.Nxf6+ Ke7 31.Nd5+ followed by Bc1 and f4 looks good for White.
A.1.c) 24... Bf6 25.Qh7+ Kf8 26.Bh6+ Ke7 27.Nd5+ as above.
A.1.d) 24... Qa3+ 25.Kb1 Bf6 (25... Bg7 26.Qh7+ transposes to A.1.b) 26.Bh6+ Ke7 27.Nd5+ Kd7 28.Nxf6+ followed by Nxe8, Bc1 and f4 looks good for White.
A.1.e) 24... Nd3+ 25.Kh1 Qxc3 26.Qh7+ Kf8 27.Bxd6+ Re7 28.Qxh8+ Qxh8 29.Rxh8+ Kg7 30.Rxa8 Rd7 31.Bf8+ Kf6 32.cxd3 wins a piece.
A.2) 23... Kg7 24.Qh6+ Kg8 25.Rh1 as above.
B) 22... Nd3+ 23.Qxd3 Qxc3 24.Qxc3 Bxc3 25.fxg6 fxg6 26.Rxb7 wins a pawn with the better position.
C) 22... Qa3+ 23.Kb1 seems to transpose to previous lines.
|Jul-12-19|| ||Cheapo by the Dozen: Unlike <NBZ>, I whiffed, because I lacked the patience or insight to see how f6 could be punched through at the right time.|
|Jul-12-19|| ||Breunor: I'm the same as Patzer 2, I went with Qh2 on the 24th move which wins pretty easily but is not the best move.|
|Jul-13-19|| ||dragonfish1803: @agb2002. After 22....,Nd3+; 23Qxd3 Black replies not 23....,Qxd3 but Kxh7. Where does White go from there?|
|Jul-13-19|| ||agb2002: <dragonfish1803: @agb2002. After 22....,Nd3+; 23Qxd3 Black replies not 23....,Qxd3 but Kxh7. Where does White go from there?>|
Good point. It seems that 24.fxg6+ followed by 25.Rh1+ or 25.Nb5 gives White more than enough compensation for the material.