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Sep-06-09
 | | An Englishman: Good Evening: Too easy, especially since I got only 3/7 right this week. The sacrifice is pretty standard in the d4,e5 vs. d5,e6 pawn structure. Black didn't even need to use the Bg7 which benefited from the sacrifice. |
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| Sep-06-09 | | RandomVisitor: The knight sac on e5 might have been played earlier, for example: 17...N6xe5 18.dxe5 Nxe5 19.0-0-0 Nxf3 20.Be4 Ne5 21.f3 Qc8 and black might win |
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Sep-06-09
| | An Englishman: Good Evening: <RandomVisitor>, I thought that 17...b5 was the star of the show, and a better choice for a Sunday puzzle move. It reminds White that castling Queen side isn't safe, and sets a trap into which Rozentalis fell. |
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Sep-06-09
 | | OBIT: The first move I considered was 19...Bxf3 to double up White's pawns. After a little thought, I decided there is no rush to do this, and besides, opening lines that lead to my king may not be too prudent. I then considered 19...Rab8 but didn't like the response 20. Bxc4. However, this line got me to think about 19...N6xe5, connectiing the knights to meet 20. Bxc4 by 20...Nxc4. The critical line has to be 19...N6xe5 20. dxe5 Bxe5. If this line looks playable, 19...N6xe5 is my move. So, let's say 19...N6xe5 20. dxe5 Bxe5. I see ...Bxc3+ is threatened. If 21. O-O Nxb2, and I pick up a third pawn for the piece, plus I like my initiative on the queenside. After 21. Qc2 Nxb2 again. Or if 21. Bxc4 Bxc3+ still looks good to me. And if 21. Bd2, I can play... umm... Hmm, after 21. Bd2 I don't like the fact that the White queen is hitting my bishop. So, now I am thinking maybe I want to play ...Bxf3 (the move I decided wasn't too prudent) after all. My new main line is 19...N6xe5 20. Bxf3 gxf3 21. dxe5 Bxe5. The reason for ...Bxf3 is so that, if White plays 22. Bd2, I can play 22...Nd2, since 23. Qxe5?? is met by 23...Nxf3+. After 19...N6xe5 20. dxe5 Bxf3 21. gxf3 Bxe5 22. Bd2 Nxd2, White must play 23. Qxd2, but then I like 23...Bf4 24. Qe2 d4. I think that's all I need to analyze. 19...N6xe5 is my move, with 20. dxe5 Bxf3 21. gxf3 Bxe5 22. Bd2 Nxd2 as my main line. |
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Sep-06-09
 | | Jimfromprovidence: The position seems unclear after 21 O-O-O.
click for larger viewI see 21...Nxf3 gxf3 Bxf3 23 Qd2 below.
click for larger viewBlack can take either rook and be up a rook and two pawns versus a bishop and a knight, but this does not seem to be enough to win. There has to be something better for black after 23 Qd2, but I can't see it. |
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| Sep-06-09 | | dzechiel: Black to move (19...?). White is up a pawn. "Insane." OK, once again champion bridge player John Swanson is helping me work on an "insane" position (he says he gets half the blame for our "analysis"). After a little back and forth, we decided we like
19...N6xe5
This (temporarily) recovers the missing pawn, and threatens 20...Nxf3+ 21 gxf3 Bxf3 forking queen and rook. 20 dxe5 Nxe5
The same threat is back on. And, once black clears the a1-h8 diagonal, the bishop on g7 will spring to life and threaten capture on c3 with check. So, how does white deal with the immediate threat (21 Nxf3+)? Does he move the rook to prevent the fork? There's no good way to put additional defenders on f3. Perhaps 21 Bd2
is correct. This defends c3 against black's dark-squared bishop AND opens the e-file to allow Qxe6+ in some variations. I'm not clear here, but it looks to me like black might play 21...Bxf3 22 gxf3 Nxf3+ 23 Kd1 Nxd2
Time to check.
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Ack! It's tough to analyze this position and watch the Dodgers-Padres ninth inning at the same time. I should have seen 21...Rxf3, that allows the knight to block the e-file and still lets the bishop provide the fork. Nuts. |
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Sep-06-09
| | OBIT: As usual, trying to solve these Sunday puzzles in game-like conditions is a little beyond my ability. Either knight can play Nxe5 on move 19, but the second capture definitely has to be with the knight, not the bishop. The clear win comes by putting pressure on f3. |
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Sep-06-09
| | OBIT: <Jim>After 23. Qd2 in your line, doesn't White also have d4 to fork two pieces? Combine that with the bishop grabbing one of the rooks, and there seems to be enough to win. |
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| Sep-06-09 | | Athamas: I actually set the pieces up on a board today since I'm doing other things while I solve this. White has a nice open h-file for his rook and looks to castle queen-side. The b-pawn for white looks relatively weak until that happens. Also both of white's knights are pinned to the king and queen. Black is down a pawn but has good compensation with piece activity, especially the knights. Both knights are aiming at the e-pawn, which takes your focus there. I looked at a few other quieter moves, but they seem to fail since white can take the c4 knight on the next move. Which leads me to my only initial move consideration 19...N4xe5
White can refuse the knight and just castle away, but that looks terrible. I think he goes ahead and takes it. 20. dxe5
Now we hit an interesting fork. Black has a couple of options I think. Push the d-pawn or simply capture the e-pawn. I think pushing the d-pawn is ok for black, but I would be more inclined to recapture the pawn and keep the initiative rather than just get the material back. 20...Nxe5
Now what to do for white? Black's pressure on the f3 knight is overwhelming. I would probably be tempted to castle and hope black took a rook. I think the other move is probably Bd2 - the reason I didn't push the d pawn. Now that I think more about it, the more I like Bd2 rather than 0-0-0... I think leaving black the option to fork the knight and bishop would give black an overwhelming advantage. 21. Bd2
Now it would probably be most tempting to play Bxf3 or Nxf3 for black but then you give up two of your most powerful attackers. I think the rook is actually less useful for black in this position. Also, white won't be able to refuse the rook sac in light of the light squared bishop still hanging. 21...Rxf3 22. gxf3
Now the knight or the bishop? It's getting critical here... must choose the right piece. 22...Bxf3
I really wanted to play Nxf3+ but in light of Kf1, it wasn't possible. Too much material for a queen. Must continue to protect the weak bishop on d3. 23. Qf1 Bxh1
Cannot capture or lose the bishop on d3 and worse position than castling 24. 0-0-0 Bf3 25. Re1
I think the knight has fulfilled its purpose. Take the bishop pair to the end game should be superior with I believe 2 extra pawns. 25...Nxd3 26. Qxd3 Bg4
That should be the end of any combination... solid advantage into the end game. Possibly 27. Qg3 Bf5 28. Rh1 type of continuation, but black's position should win. I believe this line is also superior to the 21. 0-0-0 line that I had considered for a while |
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| Sep-06-09 | | Athamas: Hmm, does it matter which knight is used? I chose the c4 knight because I was worried about capture. Say.. 19...N6xe5 20. Bxc4 Nxc4
Or am I completely off base? |
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| Sep-06-09 | | Athamas: That is what I saw as well Jim. But I decided against it after 23...d4 24. Bxd4 Bxd4 25. Bxg6 hxg6 26. Qxd4
White has a good threat here, but black doesn't need to immediately capture since both are under attack. 26...Qg5+ 27. Kb1 Qf6
I thought this line gave black a pretty clear advantage rather than the text. Or at least more room for error in the end game with the other line, perhaps not. |
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Sep-06-09
| | Jimfromprovidence: <OBIT> <After 23. Qd2 in your line, doesn't White also have d4 to fork two pieces? Combine that with the bishop grabbing one of the rooks, and there seems to be enough to win.> I thought of that, but if 23...d4 24 Bxd4 Bxd4, then 25 Bxg6, threatening Bxh7+. 
click for larger view24...hxg6 looks forced and then after 26 Qxd4 the position still looks uncertain. |
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| Sep-06-09 | | Athamas: Interesting, the start of the combination seems to actually start after 17...b5 |
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| Sep-06-09 | | lost in space: I think I got the motiv, but I am not sure if I got it completely: 19...N(6/4)xe5 20. dxe5 N(6/4)xe5
Threat: 21...Nxf3 22. gxf3 Bxf3, attacking ♕ and ♖ at the same time. The next move for white is not so clear.
Candiates: Qc2, 0-0-0, Bd2, evetually others.
I am sure white gets advantage, but a concrete line is hard to find (without board and without the help of silicons) |
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| Sep-06-09 | | VishyAnandFan: i think jim is right, after 21.0-0-0
white is better than in the game continuation |
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| Sep-06-09 | | lost in space: 21. 0-0-0 (instead of Bd2) is Rybkas first choice,
but after
21. 0-0-0 Nxf3 22. gxf3 Bxf3 23. Qd2 Rfc8 24. Bc2 Rab8 24. bd4 e5 (Rybka) Black has a pantastic position, enough to win easily (-2,3) 
click for larger view |
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| Sep-06-09 | | Once: Pins everywhere today. Not too hard to see the continuation, as long as we can avoid the temptations of alternative moves. From the starting position, I have two fantasies - one is to hit the pinned Nc3 and the other is to clobber the pinned Nf3. The Nc3 pin is absolute, but I can't see how to get at it with enough bits. And this being a puzzle position, I don't know if 0-0-0 is legal. So hitting Nf3 seems to appeal most. A knight reloader on e5 seems the best way forward. Can't claim to have seen all the variations, but I'm happy I got enough in the brief time I allowed myself. A better end to a pretty dismal week for me. |
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| Sep-06-09 | | DarthStapler: I got the first move and considered the second move |
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| Sep-06-09 | | Eisenheim: This puzzle has some a few fun concepts in it. I immediately looked to the f-file where I wanted to sac the RxN, the recapture with the B and fork the Q/R, however I realize I need another piece to support the exchange. The C4 knight needs to be used ASAP or it loses its attacking luster, so if Nxe5, dxe5, then Nxe5 looks great to smash open the center, thanks to the fun pin on F3, whites efforts to recapture are stymied. I now still attack and control the center and no matter what white plays now, I can additionally smash their defenses with the RxN I originally wanted to play. Wanted to show my thinking bc I kind of worked backwards here, or rather visualized where I wanted to go and then mapped out how to get there. |
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| Sep-06-09 | | Once: <Eisenheim> Great post! Totally agree about working backwards. Solving chess puzzles can sometimes be like solving a jigsaw puzzle. You know that you want to play Rxf3 and Nxe5, but initially you don't know where they fit in the sequence. So you need to try various permutations (or should that be combinations?) until you find a sequence that fits. |
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| Sep-06-09 | | johnlspouge: Sunday (Insane):
Rozentalis vs Bologan, 1995 (19...?) Black to play and win.
Material: Down a P. The White Ke1 has 2 legal moves, both on the back rank. The Black Qa5 pins Nc3 to Ke1. The Black Bg4 pins Nf3 to Qe2, while Rf8 also attacks Nf3. The Black Nc4 can capture Be3. Black attacks Pe5 with 3 pieces (Nc6, Nc4, and Bg7); White defends Pe5 with 2 units (the pinned Nf3 and Pd4). The closed P center hampers the Black army, which control more space than the White army. Capture of Pe5 is therefore attractive, although exposure of Pe6 could create counterplay, giving Bg4 a defensive task. In any case, the candidate is therefore likely to exploit the White weaknesses on e5, f3, and c3 (probably in order of importance). The Black Kg8 is secured from check, although White has the seeds of a counter-attack in the semi-open h-file for Rh1. Candidates (19...): N6xe5, Bxe5, N4xe5
19…N6xe5
(threatening 20…Nxf3+ 21.gxf3 Bxf3 winning more material) <[Toga prefers N6xe5 to N4xe5. I chose to capture with Nc6 instead of Nc4, because I wanted to activate Nc6.]> 20.dxe5 [else, drop at least a P]
<[Here, I went for 20…Bxe5, overlooking that in the variation 21.Bxc4 Bxc3+ 22.bxc3 Qxc3+ then 23…Qxa1+, White does not need to capture with 22.bxc3 quite so agreeably, but can move 22.Kf1 instead, retaining a P up.]> |
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| Sep-06-09 | | johnlspouge: < <Once> wrote: [snip] you need to try various permutations (or should that be combinations?) until you find a sequence that fits. > Hi, <Once>. If order matters, it is a permutation :) We have found an interesting shibboleth for those who aced their A-level maths ;>) |
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| Sep-06-09 | | Helios727: So did white resign for being 2 pawns down, or is there something more crushing coming soon? |
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| Sep-06-09 | | znsprdx: aw shucks.... if it were white to play Rxh7 looks so sweet....:) I need more coffee...one would have to see ...21. Rxf3[N]: very pretty and efficient indeed! |
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| Sep-06-09 | | remolino: Did not get this one. See you next week (tomorrow). Remolino. |
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sac: 21...Rxf3