| Apr-12-17 | | Walter Glattke: School example for h-line attack,
looks like a study, such position could be construated for books, not really a
puzzle so far. |
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| Apr-12-17 | | ChessHigherCat: Good example of "find a good move, look for a better one". QxN was too obvious and the h file was open for attack. If Black declines the sacrifice with Kf8, then Rh8 30. Kg7 Qh2 and black's goose is cooked. If Rxh7, f5/6, then Rh8 Kxh8 Qh2, etc. |
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| Apr-12-17 | | agb2002: White is one knight down.
Black threatens Nxa3, Ne3, Nc7, etc.
White can attack the black king with 29.Rxh7:
A) 29... Kxh7 30.Qh2+
A.1) 30... Kg7 31.Qh6+ Kg8 32.Rh1 f5(6) 33.Qh8+ Kf7 34.Rh7+ A.1.a) 34... Ke6 35.Qg8+ Rf7 36.Qxf7#.
A.1.b) 34... Ng7 35.Qxg7+ Ke8 (35... Ke6 36.Qf6#) 36.Rh8+ Qf8 37.Q(R)xf8#. A.2) 30... Kg8 31.Rh1 f5(6) (31... Qf6 32.gxf6 wins) 32.Qh8+ transposes to A.1. B) 29... Nxa3
B.1) 30.Qh2 f5(6) 31.Rh8+ Kf7 (31... Kg7 32.Qh6(7)#) 32.Qh7+ Ng7 unclear. B.2) 30.Rh8+ Kxh8 (30... Kg7 31.Qh2 followed by Qh7#) 31.Qh2+ Kg8 (31... Kg7 32.Qh6+ as above) 32.Rh1 Nc2+ 33.Kb2 is similar to previous lines (33... Qxb4+ 34.Nxb4 only loses decisive material). |
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| Apr-12-17 | | AlicesKnight: The likely route is 29.Rxh7, and if Black captures the Q and R go onto the R file with a rapid win. Let's see - yes. But as <agb2000> indicates, declining the R is much less decisive. |
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| Apr-12-17 | | stacase: <ChessHigherCat: Good example of "find a good move, look for a better one". QxN was too obvious ...> When I was a kid my brother drilled it into me that the object of the game was to checkmate the other guy's King, not take all his pieces. |
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| Apr-12-17 | | ChessHigherCat: <stacase: When I was a kid my brother drilled it into me that the object of the game was to checkmate the other guy's King, not take all his pieces.> That shows you had an honest brother. He could have told you that the object of the game was to expose the king and get mated ASAP :-) |
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| Apr-12-17 | | saturn2: The pieces on the d file and the white pawns form a cage around the king. So I was lead to the game continuation but would have checked with the queen first 30 Qh2. |
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| Apr-12-17 | | morfishine: Standard rook re-loader: <29.Rxh7> followed by 29...Kxh7 30.Rh1+ King any and now <31.Qh2> & Black is in a heap of trouble ***** |
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| Apr-12-17 | | zb2cr: I was able to see the correct continuation if Black accepted the Rook, but not if Black declined. |
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| Apr-12-17 | | saturn2: <But as <agb2000> indicates, declining the R is much less decisive.>
It is decisive too. He has only showm that after 29..Na3 white has to drag the black king into another check 30 Rh8 instead of 30 Qh2?! |
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| Apr-12-17 | | patzer2: A seven move mate seems a little deeper than our usual Wednesday puzzle fare. Looking at the starting puzzle position (29. ?), I figured the piece capture 29. QxN  was too simple and gave Black too much time to defend.So I switched gears and started to look at what <morfishine> calls the <standard rook re-loader> with 29. Rxh7. However, I almost gave up on that idea. That's because after 29. Rxh7 Kxh7 30. Rh1+ Kg2 31. Qh2 f6 (diagram below) 
click for larger viewI was having difficulty finding the four move mate 32.Qh8+ Kf7 33.Rh7+[] Ke6 34. Qg8+! Rf7 35. Qxf7#. After finally visualizing 34. Qg8+!, I saw the mate to follow on the next move. However, the win gets a little more complicated if Black declines the initial sham sacrifice 29. Rxh7 with 29...f6 30. Rxd7 Rxd7 31. Qxc4  (+4.63 @ 17 depth, Deep Fritz 15) P.S.: Black's game starts to go bad with the weak Knight move 22...Na5? allowing 23. b5 Nc6 24. g4 Ng2 25. Nf4 . Instead, 22...Ne5 = avoids this weakness and keeps it about level (e.g. 22...Ne5 23. f4 Ng4 24. e5 Ne3 =) |
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| Apr-12-17 | | Walter Glattke: My message to FRITZ is 29.Rxh7 f6 30.Qxc4, I saw, that 30.-Rxh7??
31.Nxf6++ brings mate (Kf8, Kh8) by Qg8. More complication, but no escape
from mate with 30.Qxc4 Qxd5 31.exd5 Kxh7
32.Rh1+ mating. |
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| Apr-12-17 | | gofer: <29 Rxh7 ...>
The rook is immune.
29 ... Kxg7
30 Rh1+ Kg7/Kg8
31 Qh2 f6/f5
32 Qh8+ Kf7
33 Rh7+ Ng7 (Ke6 34 Qg8+ Rf7 35 Qxf7#)
34 Qxg7+ Ke8 (Ke6 Qxf6#/Qf6#)
35 Rh8+ Qf8
36 Nf6#/Rxf8#/Qxf8#
So black has to open up its defensive pawn structure to allow something else to take Rh7,
but f5 is not as accurate as f6, which keeps the a1-h8 diagonal closed to the white
queen in many scenarios...
29 ... f5
30 Qxc4 ...
click for larger viewWhite has created a beautiful discovered double-check on offer; Ne7++ or Nf6++. So
even though Rh7 is still cannon fodder, there are lots of attacking lines for white. The rook has to be taken by either Kxh7 or Rxh7. But the Rxh7 seems to be a mistake
as it allows the double check!
30 ... Rxh7
31 Nf6+ Kf8
32 e5!
click for larger viewThe queen is lost, because moving it loses everything else! 30 ... Kxh7
click for larger view31 Rh1+ ...
31 ... Kg8
32 Nf6+ Kf8 (Kg7 Qg8#)
33 Qg8+ Ke7
34 Rh7+ Ng7
35 Rxg7#
31 ... Kg7
32 Qxd4+ Kf7
33 Rh7+ Ke6
34 gxf5+ gxf5
35 exf5+ Kxf5
36 Qd3+! Ke6 (Kg4 Qh3#)
37 Qe4+ Qe5
38 Qxe5#
<29 ... f6>
<30 Rxd7 Qxd7/Rxd7> The difference between these two choices at move 30 is quite subtle... <31 Qxc4 Kf8>
<32 Nxf6 Nxf6>
<33 gxf6 ...>
click for larger view33 ... Qxg4?
34 Qc5+ Kg8
35 Qe7
or 
click for larger view33 ... Qxf4?
34 Qc8+
So as none of white's pawns are under immediate threat, I would
say that both seem to be winning for white... |
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| Apr-12-17 | | Walter Glattke: 30.-Kxh7 31.Rh1+ Kg7 32.Qh1 Nc7 33.Nxf6 Rh8 34.Rxh8 Kxh8 35.Qc4 Qf8 Nxd7 |
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| Apr-12-17 | | Walter Glattke: 29.-f5 30.Rh6 is less complicated. |
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| Apr-12-17 | | Carlos0012358: Being late to the discussion I would just comment that after 29.Rxh7 black makes the blunder of taking the rook with 29....Kxh7 instead of setting up an escape route with 29....f6. Still under attack, black would have eventually lost but it would have been a game rather than a quick mate. |
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| Apr-12-17 | | stst: Suspicious of the obvious 29.Rxh7, or simply Qh2... but couldn't find any meaningful refutation from Black.
... Just pile up the two R & Q onto h, and Black couldn't break the White P-wall. |
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| Apr-12-17 | | morfishine: <patzer2> FWIW: I didn't even see the hanging Black Knight, going straight to Rxh7 Lol
***** |
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| Apr-12-17 | | NBZ: It's a shame they posted this position as a puzzle, and not the position one move before. Here Rxh7 stares out at you. But to play f4!, foreseeing that after the knight captures the bishop you have the intermezzo Rxh7 - now that takes some real imagination. |
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Kibitzing
+ sac: 28.f4