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| Jul-26-08 | | piever: I saw 19 Na6 very quickly, but after 19...bxa6 20. Rb3+ Nb7 I didn't know how to go on: 21. Qc6 Rxg2 (ouch), 21. Qxa6 Qd5, 21. Ne5 Bxe5 22. dxe5 Qg6 ... I completely missed the right 22^nd move in the third line, but I didn't spend enough time on Ne5 and there were too many lines (not to mention that there is some difference of Elo between me and Feher..) |
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Jul-26-08
 | | patzer2: For today's puzzle soluion, White decisively exploits the weakened Queenside castled position with 19. Na6+!! See <lost in space>'s post for a good analysis of the combination. As both <lost in space> and <MostlyAverageJoe> observe, the purpose of the followup 21. Ne5! is to avoid the complications of 21. Qc6 Rxg2+! or 21. Qxa6 Rxg2+! (<lost in space> indicates White still wins after 21. Qxa6 Rxg2+! 23. Kxg2 Rg8+ 24. Ng5! but that it's more difficult) or 21. Qxa6 Qd5!, when the win is not so clear. As <Alphastar> observes above, 22...Rxg2 23.Kxg2 Rg8+ is met with 24. Kh1!  . P.S.: For me the most interesting move of the game is the Zwischenzug (in between move) 21. Ne5! It asks the question, "Before I make my 'obvious' next move is there another move I can make to improve the position?" I need to do more of that to improve my own play and analysis, so I found it particularly instructive. |
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| Jul-26-08 | | RandomVisitor: What if 14...Rxf3! 15.gxf3 Nf6
1: Gyula Feher - Emmanuel Bricard, Paris 1995
click for larger viewAnalysis by Rybka 2.3.2a mp : <25-ply> 1. (-1.49): 16.Qe3 Qxh3 17.f4 Qf5 18.d5 Nxd5 19.Qf3 Re8 20.Bd2 Bxf4 21.Rfd1 a5 22.Kf1 g5 2. (-2.59): 16.Kg2 Ne7 17.Nc5 Nf5 18.Qb3 Nh4+ 19.Kh1 b6 20.f4 Re8 21.Na6+ Kc8 22.Qg3 Qd5+ |
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| Jul-26-08 | | johnlspouge: Saturday (Very Difficult): White to play and win.
Material: N+P for B. Black has a significant K-side counterattack along the open f- and g-files. With the Black Bf4 threatening Re3 and the Black Nd8 threatening Qe6, White's position is critical and requires immediate defense (i.e., if counterattack, a check or attack on Qh5). White could perform a smothered mate with Philidor's Legacy starting with 19.Nd7+, except that Nc5 will be captured at b6. Because the capture opens the Black K further, the obvious check is worthy of examination, but the resulting attack seems to peter out. In some variations, Black has a mating counterattack starting with …Rxg2+, which White must anticipate. The White Nf3 and Rf1 require activation. Candidates (19.): Nd7+, Na6+
19.Na6+ bxa6 [Ka8 20.Qc8#]
20.Rb3+ Nb7 [Kh8 21.Qc8#] 21.Qc6 (threatening 22.Qxb7#) There are 3 classes of defensive tactics, but against a mate in one they are heavily restricted: (1) counterattack (against a mate-in-one, check until the mate threat lifts); (2) reinforce present defenses; or (3) retrench and set up another defensive line (against a mate-in-one, flee with the K). In response to 21.Qc6, Black can counterattack, [snip] but I missed (1) 21…Rxg2+ 22.Kxg2 [snip]
(1.2) 22…Rg8+ 23.Ng5 [snip]
(1.2.2) 23…Rxg5+ 24.Kh1 <Rb5> i.e., the lateral defense 24...Rb5 that <MAJ> and others pointed out. Good players clearly cannot follow "a trail of breadcrumbs" to a win: they have to calculate with excruciating accuracy to avoid such pitfalls. Below, I include the variations off 19.Nd7+. Some are instructive, even if 19.Nd7+ loses. 19.Nd7+ Ka8 [Kc8 20.Ng6++ Kb8 21.Qc8#]
20.Nb6+ (threatening 21.Qc8#)
Black has 2 captures to avoid mate.
(1) 20…axb6 21.Qc8+ Ka7 22.Ra3+ Qa5 23.Rxa5 bxa5
White has won Q for R+N and has a tedious but solid win with the extra P. (2) 20…cxb6 21.Qc8+ Bb8
and now Black has a massive counterattack, and White has sacrificed an N. |
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Jul-26-08
 | | kevin86: I thought it was a smothered mate problem except the king has a hiding place at a8. The solution instead is to root out the enemy monarch and attack him in the open. |
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Jul-26-08
 | | Jimfromprovidence: Stop me if I missed something, but does not 24 Qd5+! Ke7 (forced) 25 Nc6+ win the queen?
click for larger view |
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| Jul-26-08 | | Alphastar: <Jimfromprovidence> you are right, but it's not clearly better than the game line, because either way black is completely helpless and getting trashed. |
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| Jul-26-08 | | johnlspouge: <<dzechiel> wrote: In this position white would like to play 21 Qc6 threatening mate on b7, but this would allow 21...Rxg2+ and it's white that is in hot water.> Hi, <dzechiel>. During calculation, it was unclear to me how "hot" the water was, because the only effective Black defense against the mate in one is very narrow among the plausible alternatives, and I missed it. Could you articulate your intuition about how you saw that the defense ...Rxg2+ would be successful (if you did not calculate the critical variation explicitly)? |
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| Jul-26-08 | | Slurpeeman: To be honest, I didn't try looking through all possible lines and combinations. But since White has 2 pieces en prise and black is fairly aggresive, the keymove has to be forcing (ideally, a threat of mate in 1-2) i also noted that te knight can give check that the rook on the open file will be useful after black's castled position is weakened. Definitely not "very difficult")
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Jul-26-08
| | Jimfromprovidence: Random observations:
I don’t know if anyone came right out and said it, but I think the reason white had to first play 21 Ne5 was because it was crucial to clear the diagonal so white could follow with 22 Qc6. White expected 21…Bxe5 in return, but since black erred with 21…Re8, white then pounced with 22 Qxa6. If white had played 21 Qc6 I agree that 21…Rxg2+ is the best defense. If white plays 21 Qxa6 as <MAJ> indicated, 21…Qd5 looks better. If white first plays 21 Qc6, then 21 …Rxg2+ 22 Kxg2 Rg8+ 23 Ng5 Rxg5+ 24 Kh1 Rb5 looks like a real good defense for black. 
click for larger view
Note that white cannot play 25 Rxb5 because of 25…Qh3+, with mate next move. |
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| Jul-26-08 | | Lutwidge: D'oh, I found Na6+ but somehow missed Nb7, so in an actual game I might have played the right move for the wrong reasons. Fortunately, once the position after Nb7 appears, Ne5 is not quite so hidden a resource anymore. :) |
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| Jul-26-08 | | mmmsplay10: doesn't Nd7+ work?
if Kc8, then Nb6+ followed by Qc8 mate,
and if Ka8, then Nb6+ and if Cxb6, then Qc8 mate,
and if axb6, then Qc8+ followed by Ra3+ mate. |
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Jul-26-08
 | | whiteshark: I found <19.Na6+ bxa6 20.Rb3+ Qb5 21.Qxa6 Qxb3 22.axb3> and thought it was enough material to stop. |
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Jul-26-08
 | | Once: <mmmspay10> No, Nd7+ doesn't work -
19. Nd7+ Ka8 20. Nb6+ cb 21. Qc8+ Bb8.
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| Jul-26-08 | | dzechiel: < johnlspouge: <<dzechiel> wrote: In this position white would like to play 21 Qc6 threatening mate on b7, but this would allow 21...Rxg2+ and it's white that is in hot water.> Hi, <dzechiel>. During calculation, it was unclear to me how "hot" the water was, because the only effective Black defense against the mate in one is very narrow among the plausible alternatives, and I missed it. Could you articulate your intuition about how you saw that the defense ...Rxg2+ would be successful (if you did not calculate the critical variation explicitly)?> Hi, John,
I confess that I didn't work out exact lines, but when I looked at 21 Qc6 Rxg2+ 22 Kxg2 Rg8+ it looked bad in all variations as the knight on f3 stops the queen from defending g2. I think I missed the fact that the rook on b3 can aid in the defence after the knight is given up on g5 :). I wasn't having much luck with this position. |
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| Jul-26-08 | | johnlspouge: Thanks for the response to my question, <dzechiel>. <<dzechiel> wrote: I wasn't having much luck with this position.> Maybe, but you have been doing alright on a few others this week. I just wanted to know the secret ;>) |
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| Jul-26-08 | | mikejaqua: I kept looking at Nd7+ too, but my line was 19. Nd7+ Ka8 20. Nxf8...... so what's wrong with this line? I'm sure there's something, I'm just not seeing it. |
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| Jul-26-08 | | johnlspouge: <<mikejaqua> wrote: [snip] my line was 19. Nd7+ Ka8 20. Nxf8...... so what's wrong with this line?> 20...Nxe6 21.Nxe6, and White has only R+N for Q. |
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| Jul-26-08 | | Alphastar: <mikejagua> It might be not so good idea as the white queen is attacked by the Nd8, so a plausible response for black would be Nxe6. Probably followed by Qxh3 with unstoppable mate. |
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| Jul-26-08 | | schnarre: Got this one in short order...
I had looked at Nd7+ as well, but found it lacking after closer scrutiny. I looked at the possible Queen sac by 19. Nd7 Ka8, 20. Nxf8 Nxe6, 21. Nxe6 Qxh3, 22. Nxf4 & White has N+R+B for the Queen--rendering ...Qxh3 pointless for Black. If White can promote the d-pawn, Black is finished.
In such a position 21...Bxe3 looks necessary, though after 22. fxe3 White now has center pawns. Na6+ is still better in any case! |
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| Jul-26-08 | | beginner64: I find a more decisive continuation to be 24. Qd5+. If 24.. Kc8? 25. Qa8#
If 24.. Ke7? 25. Nc6+ with loss of queen for free. |
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| Jul-26-08 | | beginner64: <Jimfromprovidence: Stop me if I missed something, but does not 24 Qd5+! Ke7 (forced) 25 Nc6+ win the queen?>
I completely agree. In fact I just posted the same line a few minutes ago, and I am *quite, quite* surprised that you were told it is "not clearly better" than the game line! Nonsense. In the game line, white is up a few pawns at end of move 28, while in your line white is up a queen at end of move 25. If those two advantages are equal, I have been wrong for many many years. |
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| Jul-26-08 | | dhotts: Doesn't 18...Bxe3 win for Black? after which White doesn't have sufficient material to force too much. Am I missing something? |
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| Jul-26-08 | | PinnedPiece: Saw the first move, but....
Since I didn't calculate 21. Ne5, I don't consider that I solved this one since 21. Qxa6 is more than defended by ...QxN. |
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| Jul-27-08 | | beginner64: <dhotts: Doesn't 18...Bxe3 win for Black? > 18... Bxe3 is not too bad for Black, but definitely doesn't win after 19. Nd7+. Black stays a pawn down and with a weak pawn structure, with simplified position after rook and minor piece exchange. |
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Kibitzing
sac: 19.Na6+