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Later Kibitzing> |
| Jun-13-20 | | Predrag3141: Not very difficult. I predicted all of it through 25 … Qxc2 (but failed to notice Black's h-pawn would be lost). The only question is what evaluation to give it, and it's reasonable to expect the pawns and mobile center to outweigh two pieces for a rook. |
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| Jun-13-20 | | andrewjsacks: May be lost anyway, but 25. exf6 a try. |
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Jun-13-20
 | | al wazir: <andrewjsacks: 25. exf6 a try.> It's more than a try. Black is busted: 25...gxf6 (25...Rxe2/Qxe2 26. fxg7#) 26. Qg6 Re6 27. Qh6 Qe3 28. Bxf6+ Rxf6 29. Qxf6+ Kxh7 30. Qxd8 Qxe2 31. Qh4+ Kg7 32. Re1. |
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| Jun-13-20 | | dick50: 25 exf6 d4
26 fxg7+ Kxg7
27 Qg6+ Kh8
No further checks. Now White has to defend g2, N and later on R and B. |
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Jun-13-20
| | al wazir: <dick50: 25 exf6 d4 26 fxg7+ Kxg7 27 g6+ Kh8> 28. Ng1 Be4 (28...Qxb2 29. Qf6#) 29. Qh6+ Kf7 30. Bxe4 Rxe4 31. Qh7+ K any 32. Qxe4. |
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| Jun-13-20 | | Brenin: White was OK until 20 Bd3, when exf6 was needed, e.g. Nexf6 21 Rf3. In the problem position, White's only apparent weakness was e3, so a capture on e5 to expose it to the Q on h6 was needed. Since 20 ... fxe5 is answered by 21 Bxe4 dxe4 22 Qc4+ Qe6 23 Qxe6 Rxe6 24 fxe5, with a slight advantage to White, it has to be 20 ... Nxe5, so that if now 21 Bxe4 then Ng4 forks h2 (mate) and e3. After 21 fxe5 Qxe3+ White gets two minor pieces for a R, but the central pawns make this a good bargain for Black. |
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| Jun-13-20 | | RandomVisitor: 24.exf6 is the suggested improvement for white. |
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| Jun-13-20 | | RandomVisitor: Does 24.exf6 cook today's puzzle?
click for larger viewStockfish_20060616_x64_modern
<60/31 27:13 0.00 20...Nxe5> 21.fxe5 Qxe3+ 22.Kh1 Nf2+ 23.Rxf2 Qxf2 <24.exf6> d4 25.Rg1 gxf6 26.Bc1 Kh8 27.Bf4 Bxg2+ 28.Rxg2 Qf1+ 29.Ng1 Qxf4 30.Bxh7 Re7 31.Bg6 Rd5 32.Qd3 Rg5 33.Qh3+ Kg8 34.Re2 Rge5 35.Rg2 59/88 27:13 0.00 20...fxe5 21.Bxe4 dxe4 22.Qc4+ Qe6 23.Qxe6+ Rxe6 24.fxe5 Re7 25.Ng3 Ba6 26.Rf4 Bd3 27.Nxe4 Nxe5 28.Nf2 Ng6 29.Rxd3 Rxd3 30.Nxd3 Nxf4 31.Nxf4 Rxe3 32.Kf2 Re7 33.Bc1 Kf7 34.g3 Rc7 35.Nd5 Rd7 36.Ne3 b5 37.h4 g6 38.Ke2 Ke6 39.Bb2 Kd6 |
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| Jun-13-20 | | TheaN: I never really considered 24.Bxh7+ (basically because I missed it completely so that's an afterthought) and thought was Black was doing fine after the text with <24.exf6 => but not more than that. Even though White's position looks shaky it is drawn. In this case the puzzle itself might be at fault, given <RV>'s analysis on 20....fxe5. Nxe5 is not wrong and definitely a better test but it's <not> winning. |
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| Jun-13-20 | | TheaN: <al wazir: <dick50: 25 exf6 d4 26 fxg7+ Kxg7 27 g6+ Kh8> 28. Ng1 Be4 (28...Qxb2 29. Qf6#) 29. Qh6+ Kf7 30. Bxe4 Rxe4 31. Qh7+ K any 32. Qxe4.> <aw> I think you're mixing up some lines here as after 25 exf6 d4! 26 fxg7+ Kxg7 27 Qg6+ Kh8 28.Ng1 Be4 29.Qh6? Qxg2#. Qh6 doesn't come with check as the bishop's in the way. SF confirms that 25.exf6 is lost. The difference is that White abandoned his defensive position with 24.Bxh7+. After <dick50>'s line it is indeed down and out for White. After 24.exf6 d4 White simply has time for 25.Rg1=, how dangerous that may look. |
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| Jun-13-20 | | RandomVisitor: White can also draw with 20...Nxe5 21.<Bxe5>.
click for larger viewStockfish_20060616_x64_modern:
<71/99 5:28:18 0.00 20...Nxe5 21.Bxe5> fxe5 22.Bxe4 dxe4 23.Qc4+ Kh8 24.b4 Rd3 25.bxc5 bxc5 26.Qxc5 Qb6 27.Qxb6 axb6 28.fxe5 Rxe3 29.e6 h6 30.Nf4 Ba6 31.Ng6+ Kh7 32.Rf8 Rxe6 33.Nf4 Rf6 34.Rxf6 gxf6 35.Rd7+ Kg8 36.Kf2 Ra3 37.Nd5 Rxa2+ 38.Ke3 Bc4 39.Nxf6+ Kf8 71/98 5:28:18 0.00 20...fxe5 21.Bxe4 dxe4 22.Qc4+ Qe6 23.Qxe6+ Rxe6 24.fxe5 Re7 25.Ng3 Ba6 26.Rf4 Bd3 27.Nxe4 Nxe5 28.Nf2 Ng6 29.Rxd3 Rxd3 30.Nxd3 Nxf4 31.Nxf4 Rxe3 32.Kf2 Re7 33.Bc1 Kf7 34.g3 b5 35.Ne2 Ke6 36.Nc3 Rb7 37.Ke2 Kd6 38.Kd3 Kc6 39.Ne4 Rd7+ |
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| Jun-13-20 | | Predrag3141: All these lines where White draws might not be much better than White's actual defense. After 27 … Re6,
click for larger viewStockfish evaluates the position as -0.75. I spent 20 or 30 minutes with Stockfish trying to figure out why, when White resigned, the evaluation was -5.92, even though the plan Black used to reach that advantage is hard to stop. So, is Stockfish wrong to evaluate the above position so favorably for White? Or did the pawn loss after 29 h4 make the difference? My best guess is that
a) A successful distraction on the kingside (not just dropping the h-pawn) was somehow possible. b) The evaluation in the above position should be a pawn or two more favorable for Black |
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Jun-13-20
 | | chrisowen: It was a track indeed h4 and e4 no? |
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| Jun-13-20 | | erichbf: 21. Bxe4 Ng4 22. Bxh7+ Kh8 23. Rf3 |
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| Jun-13-20 | | mel gibson: Not much of a puzzle -
Stockfish 11 is calling it a draw:
20... Nxe5
(20. .. Nxe5 (♘d7xe5 f4xe5 ♕h6xe3+ ♔g1-h1 ♘e4-f2+ ♖f1xf2 ♕e3xf2
e5xf6 d5-d4 ♖d1-g1 g7xf6 ♗b2-c1 ♔g8-h8 ♗c1-f4 ♗b7xg2+ ♖g1xg2 ♕f2-f1+ ♖g2-g1
♕f1-f3+ ♖g1-g2) 0.00/46 144)
score 0.00 depth 46 Draw. |
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| Jun-13-20 | | RandomVisitor: <Predrag3141><Stockfish evaluates the position as -0.75>Upon close inspection, the 6-second stockfish evaluation posted under "Engine" only reached 20-ply. This is often not deep enough to form a clear estimate of the chances in the uncertain future. As a rule, I try only to post runs longer than 3 minutes. A deeper run suggests that white is indeed in trouble, but not in an unplayable position:
click for larger viewStockfish_20060616_x64_modern:
<54/89 37:58 -1.71 28.Bf5 Re7 29.Kg1> d4 30.Bc1 Rf8 31.Be4 Bxe4 32.Nxe4 Kg8 33.Bd2 Rc7 34.a4 Rb8 35.Be1 c4 36.bxc4 Rxc4 37.Bg3 Rxa4 38.Nd6 Rf8 39.h3 Ra2 40.Bxe5 Ra5 41.Nc4 Rd5 42.Rxd4 Rxd4 43.Bxd4 Rf4 44.Bxb6 axb6 45.Nxb6 Kf7 46.Nd5 Rd4 47.Nc3 Rd2 54/83 37:58 -2.20 28.Bd3 a5 29.Bf5 Re7 30.Kg1 Rf8 31.Bg6 d4 32.Ba3 e4 33.Rxd4 cxd4 34.Bxe7 Rc8 35.Kf2 e3+ 36.Ke2 Rc1 37.Bd8 Ba6+ 38.Kf3 Rf1+ 39.Ke4 e2 40.Nxe2 Bxe2 41.Kxd4 Rd1+ 42.Ke3 Bf1 43.Bc7 Rd7 44.Bg3 Bxg2 45.Bd3 Bd5 46.Be5 Rf7 47.Kd4 Be6 |
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| Jun-13-20 | | Brenin: <erichbf>: 21 Bxe4 Ng4 22 Bxh7+ Kh8 23 Rf3 is answered by 23 ... Qxh2+ 24 Kf1, when Black has several winning lines, starting with Rxe3, d4 or Qh1+. |
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| Jun-13-20 | | Predrag3141: <As a rule, I try only to post runs longer than 3 minutes.> I'm a bit gun-shy from requesting longer runs when it hasn't finished at all. So I tend to feed Stockfish its own lines a few ply later. Is that a decent substitute from your experience? The latter is a bit like watching the deteriorating evaluation from actual play in this case, even though White dropped his h-pawn. |
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| Jun-13-20 | | agb2002: Black has a bishop and a knight for the bishop pair. White threatens exf6.
The most interesting line I've found is 20... Nxe5 21.fxe5 (21.Bxe4 Ng4) 21... Qxe3+ 22.Kh1 Nf2+ 23.Rxf2 Qxf2 24.Bxh7+ Kh8 25.exf6 Rxe2 26.fxg7# but this would be a strange solution. |
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| Jun-13-20 | | agb2002: Actually, 25... d4 wins. |
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| Jun-13-20 | | Hercdon: Based on the stockfish evaluations (Realizing that the six second versions are quite limited) it does not appear that this puzzle solves to a “winning” position. Is that a correct assessment? |
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| Jun-13-20 | | RandomVisitor: <Hercdon>Yes, the current assessment is that the puzzle position is a draw under best play. <Predrag3141><I tend to feed Stockfish its own lines a few ply later. Is that a decent substitute (for deeper runs)from your experience?>Sometimes that works. The current version of stockfish is very clever with regard to 'knowing' that 'long analysis is wrong analysis', and often spends considerable time looking at less promising alternatives in the hope that something new is learned about the ability to adapt in the uncertain future. Stockfish is free and even runs on your smartphone. The version that chessgames uses is 2.5 years old and sometimes 'misses' with very short looks at positions. |
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| Jun-13-20 | | RandomVisitor: After 20.exf6 white keeps the advantage:
click for larger viewStockfish_20060616_x64_modern:
<49/90 1:21:57 +1.04 20...Nd6> 21.Bxd7 Rxd7 22.fxg7 Rxe3 23.Be5 Ba6 24.Ng3 Rxg3 25.hxg3 Bxf1 26.Rxd5 Bb5 27.Qd2 Qg6 28.Rxd6 Rxd6 29.Bxd6 Qd3 30.Qxd3 Bxd3 31.Be5 Bb1 32.a3 Bc2 33.b4 cxb4 34.axb4 Bf5 35.Kf2 a5 36.Kf3 h5 37.Ke3 axb4 38.Kd4 b3 39.Kc3 Be6 49/90 1:21:57 +1.37 20...Nexf6 21.Rf3 Qg6 22.Bd3 Qf7 23.Ng3 d4 24.Bc4 Bd5 25.Bxd5 Nxd5 26.exd4 N7f6 27.Qc1 Rc8 28.dxc5 Rxc5 29.Qb1 Qc7 30.Be5 Qc6 31.Rdf1 Nc3 32.Qd3 Nce4 33.Nxe4 Qxe4 34.Qxe4 Nxe4 35.Rd1 Re7 36.h3 Rc2 37.Rd4 Nc5 38.Rf2 Rc1+ 39.Kh2 Nd7 |
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Jun-13-20
| | al wazir: I defer to Stockfish. |
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Jun-13-20
 | | OhioChessFan: What does SF say about 28. Bf5. Re7 29. Kg1 <Rf8> 30. Rf1 d4 31. Be4 Rxf1+ 32. Kxf1 b5 (that move is the point of the line) 33. Nf5 Rf7 34. Bxb7 Rxf5+ 35. Ke2 c4 ?
click for larger view |
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Kibitzing
sac: 20...Nxe5