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< Earlier Kibitzing · PAGE 3 OF 3 ·
Later Kibitzing> |
Apr-11-08
 | | gawain: A nice combination! Saw the first two moves, they had to be the way it started. But I, too, did not think that the e1 rook could get involved quickly enough so I never seriously considered 22 Re3. |
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| Apr-11-08 | | Brapp: What if (continuation) 26...Bf6? |
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| Apr-11-08 | | Riverbeast: <What if (continuation) 26...Bf6?> Munch on f6 (check)...Munch on g6 (check)....After black plays ...Qg7 then Qh5, threatening Rg3 Finita la commedia
Nunn got out-Nunned in this game |
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| Apr-11-08 | | YouRang: <SolaGracia><This was my first post and I have always been afraid to say anything totally wrong, and it didn't take many posts to do it!> TWO STEPS TO LEARNING:
1. Being willing to make a mistake.
2. Being able to admit making a mistake.
You're already ahead of a lot of people! Welcome aboard <SolaGracia>. :-) |
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| Apr-11-08 | | Riverbeast: <SolaGarcia> Chess is a difficult game...we're all learning here...There's nothing wrong with making mistakes in analysis, even GMs do it |
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| Apr-11-08 | | znprdx: After 20.Bxf7+ Nunn missed the best move: Resigning. Not bad for a Wednesday puzzle:) |
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| Apr-11-08 | | patzer2: For today's Friday April 11, 2008 puzzle solution, White plays a winning demolition of pawn structure combination beginning with 20. Bxf7+!! |
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| Apr-11-08 | | frankmarshall: Why can I always see the obvious but never follow through. Bxf7+ was the first move that came to my head, it just looks right, but I couldn’t finish it out. I spent some time looking at this one. |
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| Apr-11-08 | | TrueBlue: nice puzzle, but Re3 was a blunter. The natural Qg7 is much stronger (e.g. follow with Qxg6 and Ng7+, which wins a rook). |
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| Apr-11-08 | | MaczynskiPratten: <eblunt: From the game, I thought black might be better trying 22... Qxc3> I agree, I couldn't see a clear refutation of this. Another argument against 22 Re3 perhaps. Though no doubt I'm missing something - surely Nunn would have seen it! |
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| Apr-11-08 | | wals: Static Evaluation: White is down a pawn. Black has a passed pawn.
All pieces are on the board.
Dynamic Evaluatuion: White's bishop pair are directed at the black King.
The white diag. bishop has a clear line to give check and must win an Exchange.
The f5 Knight can also deliver check on h6.
Dynamic Assessment: What if Ng3+, King moves g7. not much future in that.
Try Ba2xf7+ King must move h8, now must move the Queen to .h3.
Reasonable moves: Bxf7+, Nh6+ Nxe7+
Have a go,
20.Bxf7+ ...Kh8 21.Qh3 ...gxf5 22.Bf7-g6
PM=
No dipped out again, Nd7-f6 scuttled that line. even when 21. Bxg6. |
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| Apr-11-08 | | johnlspouge: Here are the Mom-and-Pop Toga II 1.3.1 evaluations today. I have put <the last move entered into the computer> in angle brackets, so the first move after the angle brackets is computer analysis of the corresponding best line. [ply 15/73, time 07:18, value +1.93]
20.<Bxf7> Kxf7 21.Qxh7+ Kf6 22.Qg7+ Ke6 23.Qxg6+ Nf6 24.Nf3 Nb3 25.Rad1 Qxc3 26.Nxe7 d2 27.Rf1 Rxe7 28.Ng5+ Kd7 29.Qf5+ Ke8 30.Qxf6 Nc5 31.Qg6+ Kd7 32.Bxc5 dxc5 [ply 15/48, time 02:33, value +3.71]
20.Bxf7 <Kh8> 21.Bxg6 Nf6 22.Qh4 Rg8 23.Bxd6 Bxd6 24.Qxf6+ Rg7 25.Re3 Rf8 26.Qxg7+ Qxg7 27.Nxg7 hxg6 28.Rxd3 Bc5 29.Ne6 Bxf2+ 30.Kf1 Rf6 31.Rd8+ Kh7 32.Nf3 Be3 33.Rd7+ Kh6 [ply 15/66, time 04:13, value +1.45]
20.Bxf7 Kxf7 21.Qxh7+ Kf6 22.<Re3> Nf8 23.Qh8+ Ke6 24.Qh3 Kf7 25.Rf3 Bf6 26.Nxd6+ Kg7 27.Nxe8+ Rxe8 28.Rxd3 Rd8 29.Rd1 Rxd3 30.Bxf8+ Kxf8 31.Qxd3 Kg8 32.Qg3 Qf7 The main conclusions are: (1) Black is better accepting than refusing the sacrifice 20.Bxf7 (surprise!) and (2) 22.Re3 is 0.48 Ps worse than 22.Qg7+. |
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| Apr-11-08 | | Eyal: <MaczynskiPratten: <eblunt: From the game, I thought black might be better trying 22... Qxc3> I agree, I couldn't see a clear refutation of this.> The clearest refutation is by 23.Rf3, with mate in 7 moves at the most: 23...Qxa1+ 24.Nf1 Bxe4 25.Nh4+! Kg5 26.Rg3+ Kf4 27.Qh6+ g5 28.Rg4+ Kxg4 29.h3+ Kf4 30.g3#. 22...Nf8 is indeed the best defense - Black's missed his chance to put up more resistance a move later,with 23...Kf7 instead of Ke6. |
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Apr-11-08
 | | Jimfromprovidence: <TrueBlue> <nice puzzle, but Re3 was a blunter. The natural Qg7 is much stronger (e.g. follow with Qxg6 and Ng7+, which wins a rook).> If 22 Qg7+, then 22...Ke6 23 Qxg6+ Nf6 2 Ng7+ Kd7.
click for larger viewWhite can exchange knight for rook and be slightly ahead, having a rook and 2 pawns vs. a knight and a bishop. It's not as good as the text. |
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| Apr-11-08 | | YouRang: <Jimfromprovidence><It's not as good as the text.> IMO that's not a fair comparison since the text is flawed. Black should have played 23...Ke6. <TrueBlue>'s line probably is better in that case (although maybe still not the best). |
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| Apr-11-08 | | MostlyAverageJoe: <Domdaniel: <MAJ> -- <Puzzles that make engines sweat> is a brilliant idea for a games collection, but, um, you don't seem to have much in it yet.> Thanks for the kind characterization of my idea :-) I've just started this collection today, with this game as the first one. <Jimfromprovidence> and others, the line played in the game is most definitely NOT a solution. Both 22.Nh6 and 22.Qg7 are substantially stronger than the rook lift 22.Re3. However, it takes a lot of effort to disprove Re3 -- no wonder that Nunn blundered into a loss with Kf7? I obtained this as the initial mainline:
22. Nh6 Rf8 23. Re3 Nc5 24. Bxc5 dxc5 25. f4 exf4 26. e5+ Ke6 27. Rxd3 Qxe5 28. Qxg6+ Rf6 29. Qg4+ Rf5 30. Nxf5 Qxf5 31. Re1+ Kf6 32. Qh4+ Qg5 33. Qxg5+ Kxg5 34. Rxe7 
click for larger viewThe above evaluates at about +5.25. Backsliding identifies a couple of possible minor improvements for the black: 25... Bd6 26. fxe5 Bxe5 27. Rf1 Ke6 (about 0.6 improvement) 24... Ke6 25. Bb4 Nc6 26. Ba3 Kd7 (about 0.2 improvement) 23... Nb6 24. Ng8 Ke6 25. Qxg6 Kd7 (about 0.50 improvement) 22... Rf8 23. Re3 Nb6 24. Ng8 Ke6 (about 0.50 improvement) However, I did not explore these side variations, so the alleged improvements for the black might be illusory. The improvements are NOT cumulative; the bottom line is that 22.Nh6 after backsliding evaluates at +4.60 or so, definitely winning. 22.Qg7 is better than +2.50. On the other hand, the rook lift might produce something like: 22. Re3 Nf8 23. Qh8+ Ke6 24. Ng7+ Kd7 25. Rxd3 Nc4 26. Qh3+ Kd8 27. Nxc4 Qxc4 
click for larger view
This evaluates at about +1.00 after over an hour of CPU time spent (and only 18 plies deep), and the score decreases with the increasing depth of the analysis -- this is not a good sign for white. If you think that white can improve the above line after Re3, please post your improvement suggestions. |
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| Apr-11-08 | | MostlyAverageJoe: BTW, please also take a look at analysis of <22.Nh6!> by <Eyal>. My apologies for not recognizing it earlier. Here's the direct link: J L Arnason vs Nunn, 1990 After looking at the consequences of 22.Nh6, it seems that 21...Ke6 might have been marginally better for the black than 21...Kf6. |
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Apr-11-08
 | | ajk68: Can black escape with 24...Ke6?
Am I missing something? |
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Apr-12-08
| | Jimfromprovidence: To <YouRang> <MAJ> and others. I did not mean to imply that 22 Qg7+ was not worthy. I was responding to <TrueBlue>'s exact continuation only:
<The natural Qg7 is much stronger (e.g. follow with Qxg6 and Ng7+, which wins a rook).> My analysis showed that his specific 3 move example did not seem to lead anywhere, not even better than the text 22 Re3. I never said that 22 Re3 and subsequent moves in the match were optimal. |
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| Apr-12-08 | | Eyal: <ajk68: Can black escape with 24...Ke6? Am I missing something>
24...Ke6 25.Qh3 Kd7 26.Nxe7+ Kd8 (26...Kxe7 27.Qh4+ Ke6 28.Rf6+ Kd7 29. Rf7+ Kc8/c6 30.Rxc7+) 27.Nd5 and White has gained back the piece with a vastly superior - practically winning - position. But it should be somewhat better for Black than the actual game. |
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| Apr-12-08 | | Calli: 24...Ke6 25.Nxe7 wins since Q or R x e7 then Qh3#, or Kxe7 Qh4+ |
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| Apr-12-08 | | YouRang: Hello <Jimfromprovidence> <I did not mean to imply that 22 Qg7+ was not worthy.I was responding to <TrueBlue>'s exact continuation only: <The natural Qg7 is much stronger (e.g. follow with Qxg6 and Ng7+, which wins a rook).> My analysis showed that his specific 3 move example did not seem to lead anywhere, not even better than the text 22 Re3. I never said that 22 Re3 and subsequent moves in the match were optimal.> Yes, even so, you seem to hold the opinion that <TrueBlue>'s line was not better than the <22.Re3> in the text. I suspect that <TrueBlue>'s line was slightly better (although he overstated it by saying it "wins a rook"). No big disagreement here. Personally, I think the 'best' line is what I mentioned previously: 22. Qg7+ Ke6 23. Qxg6+ Nf6
At this point white's bishop sac gained 3 pawns and exposed the king, with attack. Good compensation already :-) The best continuation I think is 24. Nf3! (rather than Ng7+). Then 24...Kd7 25.Nxe7 25...Rxe7 (if 25...Kxe7 then 26.Qg7+ wins the knight) 26. Qxf6. White has recovered the sacrificed piece, and is up a couple pawns & has a solid winning game. |
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Apr-12-08
| | Jimfromprovidence: <You Rang> <Yes, even so, you seem to hold the opinion that <TrueBlue>'s line was not better than the <22.Re3> in the text.> <I suspect that <TrueBlue>'s line was slightly better (although he overstated it by saying it "wins a rook"). No big disagreement here.> Yes, I do think that that line is lousy, because 24 Ng7+ is not good. |
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| Apr-12-08 | | MostlyAverageJoe: <Jimfromprovidence: To <YouRang> <MAJ> and others. I did not mean to imply that 22 Qg7+ was not worthy.
I was responding to <TrueBlue>'s exact continuation only: <The natural Qg7 is much stronger (e.g. follow with Qxg6 and Ng7+, which wins a rook).> My analysis showed that his specific 3 move example did not seem to lead anywhere, not even better than the text 22 Re3.> Sorry, but your analysis was stopped too short to show such a thing. You said: <If 22 Qg7+, then 22...Ke6 23 Qxg6+ Nf6 2 Ng7+ Kd7. ...
White can exchange knight for rook and be slightly ahead, having a rook and 2 pawns vs. a knight and a bishop.
It's not as good as the text.>
The continuation of the above line can be found in my first two posts on the first page of comments, quite a bit preceding <TrueBlue>' post. Incidentally, this is really <zooter>'s line, since mine transposes to his <20.Bxf7+ Kxf7 21.Qxh7+ Ke6 22.Qxg6+ Nf6>. This line is somewhat better for white than what happens after the best defense to 22.Re3. As <YouRang> mentioned, the line played in the game is flawed by the huge blunder (22...Nf8??), so it should not be used as a reference of any kind. You really should look at the 22. Re3 Nf8 23. Qh8+ Ke6 24. Ng7+ Kd7 25. Rxd3 Nc4 26. Qh3+ Kd8 27. Nxc4 Qxc4 continuation I posted earlier. While I did not play out either line to the end, I noticed that descending into a continuation of 22. Re3 tends to decrease white's advantage to under 1.00, while descending into a continuation of 22. Qg7+ tends to increase it. I see absolutely no evidence supporting your claim. |
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Apr-12-08
| | Jimfromprovidence: <MAJ> OK. I went back and read the earlier posts. (I did not review them before I had posted; my original post was based on <TrueBlue>’s comments). You said the evals are about 1.60 after 22. Qg7+ Ke6 23. Qxg6+ Nf6 24. Ng7+ Kd7 25. Qf5+ Kc6, then continuing with 26. Nxe8 Rxe8 27. Qh3 Nd7. After 22. Qg7+ Ke6 23. Qxg6+ Nf6 24. Ng7+ Kd7 in that continuation, I was seeing only about a .5-point gain for white, compared to a 1 point or so gain for 22 Re3, etc. That’s why I posted what I did. After 27…Nd7, what happens next?
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< Earlier Kibitzing · PAGE 3 OF 3 ·
Later Kibitzing> |
Kibitzing
sac: 20.Bxf7+