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May-01-09
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| johnlspouge: Friday (Difficult):
Bologan vs Movsesian, 2005 (17.?) White to play and win.
Material: Down a P. The Black Kg8 has 2 legal moves. The White Bc4 pins Pf7 to Kg8, making the square g6 accessible to the White Qc2. The White Bb7 on the long diagonal adjacent to Kg8 eyes Pg7 and the flight square h8 behind, while the White Qc2 eyes the luft square h7 from behind the White Ne4. The White Rd1 has an open file and attacks Nd7. Both White Ne4 and Nf3 are near the Black K-position. The White Kg1 is secured from all but …Qxh2+. Candidates (17.): Rxd7, Nxf6+, Qg6, Qc3
17.Rxd7
As a preliminary to shifting the attack from the light squares to the dark squares, White eliminates a defender of the dark square f6. (1) Black can counterattack:
17…Nxc2 18.Rxc7
On the next move, White can take Bc8 or Be7, giving himself a minimum of B+N for R+P. (2) As another counterattack, the Black Qc7 cannot preemptively immolate herself to any profitable end: 17…Qxh2+ 18.Kxh2 Nxc2 19.Rxe7
Black wins Q+B+N for Q+P.
(3) Black can recapture in 2 ways, leading to defensive opportunities of significantly different quality. 17…Qxd7 [Bxd7 is worse] 18.Qc3 (threatening 19.Qxg7#) (3.1) Defense by interposition fails immediately:
18…Bf6 19.Nxf6+ gxf6 [Kh8 20.Nxd7 (threatening 21.Qg7#)] 20.Qxf6 (threatening 21.Qxg7# or 21.Qh8#)
Black has no feasible defense.
(3.2) Defense by protection is available for the recapture 17…Qxd7, but not 17…Bxd7: 18…Qg4 19.Nfg5 (threatening 20.Qxg7#)
19…Bf6 20.Nxf6+ gxf6 [Kh8 21.Nxg4]
20.Qxf6 (threatening 21.Qxg7# or 21.Qh8#)
Black has no feasible defense.
Although the game variation 19...Qxg5 is best play accordingly to Toga, I (rightly) ignored it as completely infeasible. |
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| May-01-09 |
| Patriot: <johnlspouge: ...Although the game variation 19...Qxg5 is best play accordingly to Toga, I (rightly) ignored it as completely infeasible.> I "almost" agreed with you on this. It's true that immediately black will be down a queen for the exchange, a knight, and a pawn, but after 20...Bf6 if white doesn't play accurately the game could nearly equalize. For example, 21.Qc1? Bxg5 or 21.Qd2? Bxg5. And the game move 21.Qf3! is harder to spot than what happens in your line (19...Bf6 20.Nxf6+ gxf6 21.Qxf6 and mate next). Dynamics clearly rule over material here, so from a practical standpoint 19...Qxg5 is best. |
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May-01-09
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| kevin86: Funny how some of these games work-white sacrifices material and then wins with a crushing material edge. The same chutzpah is employed by following someone in a revolving door and then coming out first! |
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May-01-09
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| JG27Pyth: 1/4 Partial credit. Didn't find Black's best defense and the winning 19.Nfg5! |
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| May-01-09 |
| remolino: 17. Rxd7 17...Qxd7; 18. Qc3 |
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May-01-09
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| Jimfromprovidence: I liked 21 Qf3 a lot, not only because of the pressure it puts on f7 but also because it directly attacks black’s rook on a8. 
click for larger view So, if Black tried instead 21 ...hxg5, then 22 Bxf6. If 22...gxf6, then 23 Qxa8. 
click for larger viewAlternatively, if after 21…hxg5 22 Bxf6 Be6, then white can retreat the bishop to b2 (or b1). 
click for larger view |
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May-01-09
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| doubledrooks: I went in for 17. Rxd7!.
Now if 17...Nxc2, there could follow 18. Rxd7 Bd8 19. Rc6 Nb4 19. Rg6. Another line is 17...Qxd7 18. Qc3 Qg4 19. Nfg5! Qxg5 20. Nxg5 Bf6 21. Qd2 Bxg5 22. f4 and white has a queen for rook and knight. |
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May-01-09
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| Kasputin: Maybe I am missing something, but this does not seem especially complicated. White has lots of pieces trained on black's kingside, and white also has a threatened queen. The automatic reaction is to move the queen away, but I think a better move is to play: 17. Rxd7
Getting rid of this knight is important because it covers the f6 square. It does not make sense for black to now capture the white queen because black simply captures the black queen and is up a piece. So black will capture the d7 rook with the queen or the bishop. This leads to: 18. Qc3
Now mate is threatened. Black's f-pawn is pinned, so there is really only one move: 18 ... Bf6. 19. Nxf6+
Now if black captures the f6 knight with the g-pawn then white plays 20. Qxf6 and black will be mated next turn. If black moves the king to h8, then the white knight captures whatever is sitting on d7 (the queen or the bishop) and again mate looms. It would now be possible to move ...f6 but then the white knight on d7 can retreat and white ends up with three minor pieces for the rook and black's position still looks quite precarious. Interestingly, if the black queen were on the d7 square, then the defence 18 ...Qd4 won't work because of white's f3 knight covers the d4 square. Also in some the variations it might be possible to throw the black queen unto e5 but that looks like delays things for a move - white can just capture the queen with the same threats. All of white's pieces are in the right spot. I suspect that black resigned after 18. Qc3. So now it is time to see if I really did miss something (which I have done a lot of lately) or if this is fairly straightforward afterall. |
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May-01-09
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| Kasputin: And once again, I missed the most stubborn black defence... |
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| May-01-09 |
| Big Easy: I played with the idea of Rxd7 but abandoned it when I couldn't find anything definitive. I certainly wouldn't have found the terrific move 19. Nfg5!! which costs black his queen. |
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May-01-09
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| doubledrooks: I missed white's best move after 17. Rxd7 Qxd7 18. Qc3 Qg4 19. Nfg5! Qxg5 20. Nxg5 Bf6, which is 21. Qf3 as played. |
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| May-01-09 |
| Big Easy: By the way, what's the continuation after black takes the knight on h6? If white plays 26. Qxb4 then could black answer with 26...c3 and have a small chance with the threat of a passed pawn? |
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| May-01-09 |
| centralfiles: <SamAtoms1980: I got as far as 17 Rxd7!! Qxd7 before stumbling with 18 Nf6+ Bxf6 19 Bxf6 gxf6>
you missed 19...NxQ |
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| May-01-09 |
| centralfiles: isn't 22Bxf7+ more accurate mating immiediately i.e. 22...Kh8 23.Qe4 mates |
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May-01-09
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| YouRang: Well this struck me as fairly straight-forward (it helps when you don't consider all of the possible black replies). But with my queen under attack, I naturally want to play Qc3 with mating threats. But black can then play ...Bf6, which is effective because the bishop is guarded by black's N and black's Nd7. So, I begin instead by taking out the N with 17.Rxd7! threatening Rxc7. Exchanging queens works in white's favor, e.g. 17...Nxc2 18.Rxc7 Bd8 19.Rxf7! Rxf7 20.Nd6, winning. So black must take the Rd7, and now I can play 18.Qc3 with mate threats, and black can't block with ...f6 since Pf7 is pinned. I figured black would resigned because I didn't notice 18...Qg4 (but if I had, I think I would have spotted 19.Nfg5, blocking the Q's defense of Pg7. :-) |
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| May-01-09 |
| MaczynskiPratten: <centralfiles: isn't 22Bxf7+ more accurate mating immiediately i.e. 22...Kh8 23.Qe4 mates> 23...hxg5 seems to scupper that |
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May-01-09
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| agb2002: Black is a pawn ahead and threatens 17... Nxc2. If 17.Qc3 then 17... Nf6 threatening 18... Nxa2 and 18... Bb7 seems to hold. Therefore, 17.Rxd7: A) 17... Nxc2 18.Rxc7
A.1) 18... Re8 19.Bxf7+ Kxf7 20.Nd6+ Kf8 21.Ne5 (or 21.Nxe8 Kxe8 22.Nc6) A.1.a) 21... Bf6 22.Ng6+ Kg8 23.Bxf6 gxf6 (23... Re6 24.Rxg7#) 24.Nxe8 + -. A.1.b) 21... Bxd6 22.Ng6+ Kg8 23.Rxg7#.
A.1.c) 21... Bf5 22.Nxf5 Bf6 23.Ng6+ Kg8 24.Bxf6 gxf6 25.Rg7#. A.1.d) 21... Nd4 22.Ng6+ Kg8 23.Nxe7+ + -.
A.2) 18... Bd8 19.Rxf7 Rxf7 20.Nd6 Ra7 21.Nxc8 + -.
B) 17... Qxd7 18.Qc3
B.1) 18... Qg4 19.Nfg5 Bf6 20.Nxf6+ gxf6 21.Qxf6 Qd4 22.Qg6+ and mate next. B.2) 18... Bf6 19.Nxf6+ gxf6 20.Qxf6 Qd4 21.Bxd4 cxd4 22.Qg6+ Kh8 23.Qxh6+ Kg8 24.Ng5 + -. C) 17... Bxd7 18.Qc3 Bf6 19.Nxf6+ gxf6 20.Qxf6 + -.
D) 17... Qf4 18.Qc3 Bf6 19.Nxf6+ + -.
Time to post and check. |
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| May-01-09 |
| DarthStapler: I got the first two moves |
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| May-01-09 |
| ruzon: I did not see the Qg4 defense, and I did not see Nfg5 while playing through the game. And I'm okay with that today. |
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| May-01-09 |
| gofer: perhaps its...
17 Rxd7 Qxd7
18 Qc3 Qg4
19 Nfg5 winning...
time to check.... |
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| May-01-09 |
| WhiteRook48: I did not see 17 Rxd7 |
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May-01-09
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| johnlspouge: < <Patriot> wrote : < <johnlspouge> : ...Although the game variation 19...Qxg5 is best play accordingly to Toga, I (rightly) ignored it as completely infeasible.> I "almost" agreed with you on this [snip] but after 20...Bf6 if white doesn't play accurately the game could nearly equalize. > With humans able to improve near the end of the full computer variation and the <emphasized move> the last entered, Toga gives [ply 15/53 time 00:48 value +3.73]
17.Rxd7 Qxd7 18.Qc3 Qg4 19.Nfg5 Qxg5 20.Nxg5 Bf3 21.<Qg3> hxg5 22.Bxf6 gxf6 23.Qf3 Be6 24.Qxf6 Rfe8 25.Qxg5+ Kf8 26.Qh6+ Kg8 27.f4 Bxc4 28.Qg5+ Kf8 29.bxc4 Rad8 30.Qh6+ Kg8 31.Qxb6 Rd2 32.Qxc5 Nxa2 The move 21.<Qg3> does nothing more than dodge the direct threat (e.g., Toga later moves 23.Qf3), but it still evaluates at more than a minor piece. < <agb2002> wrote: [snip] B.1) 18... Qg4 19.Nfg5 Bf6 20.Nxf6+ gxf6 21.Qxf6 Qd4 22.Qg6+ and mate next. > Others humans apparently felt the variation 19...Qxg5 was not worth including. I am sorry, <Patriot>: I have had a bad week so far, and I intend to take this one ;>) |
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| May-01-09 |
| newzild: <Big Easy: By the way, what's the continuation after black takes the knight on h6? If white plays 26. Qxb4 then could black answer with 26...c3 and have a small chance with the threat of a passed pawn?> 25...Kxh6 26.Qxb4 c3 27.Qh4+ Kg6 28.Qe4+ (black any) 29.Qxa8 is an easy win since white can sacrifice his rook for the c3 pawn and still have a Queen and three pawns for two bishops. |
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May-01-09
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| patzer2: For today's Friday puzzle solution, Bologan's 17. Rxd7!! uses the deflection tactic to removes a key guard or defender to enable a decisive King-side attack. During the follow-up, the obstruction sham sacrifice 19. Nfg5! forces the loss of the Black Queen and gives White a winning material advantage. Bologan's excellent play was sufficient to score the full point. However, the alternative 22. Bxf7+! appears to be slightly stronger as White has a winning pinning combination with the forcing 22...Kh8 23. Qxa8 hxg5 24. Be6 Nxa2 Bxc8  . |
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| May-02-09 |
| TheBish: Bologan vs Movsesian, 2005 White to play (17.?) "Difficult"
Material: White is down a pawn.
I often have a clue as to what the key move is by glancing at the diagram, but I didn't have a clue until I starting doing some analysis. My line of thinking went like this: White's queen is attacked, so he must move his queen, unless there is another move that threatens mate (none exist) or a sacrifice, most likely with check, that precedes a queen move. I then noticed that 17. Qc3 threatens mate, but Black has two defenses, 17...Nf6 and 17...Bf6 (since 17...f6 is not possible due to the pin by the Bc4). After 18. Nxf6+ following either of these defenses, Black stands well after recapturing. But what if there was a way to remove one of these defenders first? That's when I found it... 17. Rxd7!
The zwischenzug! (In-between move.) Now 17...Nxc2 18. Rxc7 loses a piece, so Black must try either 17...Bxd7 or 17...Qxd7. There's not much difference, so we'll try each one. A) 17...Bxd7 18. Qc3 Bf6 19. Nxf6+ Kh8 (or 19...gxf6 20. Qxf6 and White is mating) 20. Nd5! and White wins the queen or mates. B) 17...Qxd7 18. Qc3 Qg4 (18...Qd4 19. Nxd4 is out of the question, and 18...Bf6 19. Nxf6+ gxf6 20. Qxf6 mates next on g7 or h8) 19. Nfg5! (I didn't see this the first time around) Bf6 20. Nxf6+ and once again, White wins the queen or king, i.e. 20...gxf6 21. Qxf6 Qxg5 22. Qh8 mate. |
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sac: 17.Rxd7
