Difficult Test Position: Positional Sacrifice

[Dann Corbit]

Rybka 3 just gave me a fail high on this position and is doing a research:
[d]rnbq1rk1/pp4bp/3p4/2pPP2n/2P5/2NBp3/PPQ1N1PP/R3K2R w KQ -

I will report the analysis tomorrow.

I had a power outage but restarted the analysis. I guess the less exciting rescue of the bishop is probably the better move. I would be tempted to play the pawn push over the board, because I like the pressure it puts on the opponent's king, even though the compensation is not really adequate according to computer analysis.

Anyway, here is the output of Rybka after a good think on the above position {which is after the pawn push and the bishop capture}:

Code: Select all

12/31/2008 1:27:44 AM Level: 36000 Seconds
Analyzing engine: Rybka 3

1) Bxh7 I think";       
    Searching move: Bd3xh7
    Best move (Rybka 3): e5-e6
    Not found in: 10:00:00
      2	00:00	         738	47.232	-1.42	Bd3xh7+
      2	00:00	         888	56.832	-1.33	e5xd6
      3	00:00	       1.548	99.072	-1.16	e5xd6
      4	00:00	       2.453	78.496	-1.03	e5xd6
      5	00:00	       3.666	117.312	-1.19	e5xd6 Nh5f6
      5	00:00	       6.092	99.019	-0.99	e5e6 Bg7xc3+
      6	00:00	      12.322	134.231	-1.07	e5e6 Bg7xc3+ Ne2xc3 Qd8e7
      6	00:00	      14.849	120.677	-1.04	e5xd6 Nh5f6 OO
      7	00:00	      25.450	138.621	-1.06	e5xd6 h7h6 OOO Qd8xd6
      7+	00:00	      31.122	135.612	-0.84	e5e6
      7	00:00	      33.442	128.739	-0.78	e5e6 Bg7xc3+ Ne2xc3 Qd8e7 OOO
      8	00:00	      82.186	158.490	-0.79	e5e6 Rf8f2 Bd3xh7+ Kg8h8 Bh7e4 Nb8a6
      9	00:01	     152.818	161.658	-0.71	e5e6 h7h6 OOO Rf8f2 g2g3 Nh5f6
     10	00:02	     319.348	159.986	-0.59	e5e6 Rf8f2 Bd3xh7+ Kg8h8
     11	00:05	     903.702	168.990	-0.63	e5e6 Kg8h8 OOO Rf8f2
     12	00:06	   1.067.202	167.970	-0.54	e5e6 Kg8h8 OOO Nb8a6 a2a3 Rf8f2 g2g4 Nh5f4 Nc3e4 Rf2g2 Rd1g1
     13	00:09	   1.448.092	166.163	-0.53	e5e6 Kg8h8 OOO Nb8a6 a2a3 Rf8f2 g2g4 Nh5f4 Nc3e4 Rf2g2 Rd1g1 b7b5 Rg1xg2 Nf4xg2 c4xb5 Na6c7
     14	00:24	   4.031.027	173.727	-0.47	e5e6 Kg8h8 OOO Nb8a6 a2a3 Nh5f4 Bd3xh7 Nf4xe2+ Nc3xe2 Rf8f2 Bh7e4 Qd8f6 Rh1e1 Qf6e5 Be4f3 Ra8b8 Qc2b3
     15	01:24	  14.700.962	179.128	-0.33	e5e6 Bg7xc3+ Ne2xc3 Kg8h8 g2g3
     16	04:52	  51.631.294	180.636	-0.27	e5e6 Kg8h8 OOO Nb8a6
     17	07:31	  78.971.118	179.094	-0.23	e5e6 Kg8h8 OOO Nb8a6 a2a3 Nh5f6 Rh1f1 Nf6g4 Bd3xh7 Ng4f2 Rd1e1 Qd8h4 Bh7g6 Rf8f6 Bg6e4 Qh4xh2 Nc3b5 b7b6 Kc1b1
     18	13:40	 144.947.477	181.034	-0.21	e5e6 Kg8h8 OOO Nb8a6 a2a3 Rf8f2 Rd1f1 Na6c7
     19	20:03	 208.140.307	177.199	-0.28	e5e6 Kg8h8 OOO Nb8a6 a2a3 b7b5 c4xb5 Na6c7 Bd3xh7 Qd8g5 g2g4 Qg5xg4 Rh1g1 Qg4h4 Bh7f5 Bg7h6 Kc1b1 Ra8b8 Rd1f1 Nh5g7 Ne2g3
     20	40:41	 439.322.948	184.258	-0.22	e5e6 Kg8h8 OOO Nb8a6 a2a3 b7b5 c4xb5 Na6c7 Bd3xh7 Qd8g5 g2g4 Qg5xg4 Rh1g1 Qg4h4 Bh7f5 Bg7h6 Kc1b1 Ra8b8 Rd1f1 Nh5g7 Ne2g3
     21	1:09:01	 761.939.100	188.426	-0.25	e5e6 Kg8h8 OOO Nb8a6 a2a3 b7b5 c4xb5 Na6c7 Bd3xh7 Rf8f2 Nc3e4 Ra8b8 a3a4 Bc8b7 Ne4xf2 e3xf2 Bh7e4 Qd8g5+ Kc1b1 Nc7xd5 Be4xd5 Bb7xd5 Rh1f1 Bd5xe6 Rf1xf2 Bg7e5 Rd1f1 Nh5f6 h2h4 Qg5h6 Ne2f4
     22	2:48:44	1.979.606.534	200.232	-0.25	e5e6 Kg8h8 Bd3f5 Nb8c6 d5xc6 b7xc6 OOO Bg7e5 Rd1f1 Nh5g7 Bf5xh7 Bc8xe6 Bh7e4 Be6xc4 Be4xc6 Ra8b8 b2b3 Bc4xe2 Rf1xf8+ Qd8xf8 Nc3xe2 Qf8f2 Bc6f3 Ng7e6 h2h4 Ne6d4 Ne2xd4 Be5xd4 Qc2xf2
     23	3:47:35	2.702.439,629	202.657	-0.32	e5e6 Kg8h8 Bd3f5 Nb8c6 d5xc6 b7xc6 OOO Bg7e5 Rd1f1 Nh5g7 Bf5xh7 Bc8xe6 Bh7e4 Be6xc4 Be4xc6 Ra8b8 b2b3 Bc4xe2 Rf1xf8+ Qd8xf8 Nc3xe2 Qf8f2 Bc6f3 Ng7e6
     24	6:24:14	4.691.819,289	208.399	-0.41	e5e6 Kg8h8 Bd3f5 Nb8c6 d5xc6 b7xc6 OOO Bg7e5 Rd1f1 Qd8e7 Bf5xh7 Bc8xe6 Bh7f5 Ra8b8 Qc2d3 Nh5f4 Ne2xf4 Be6xf5 Qd3xf5 Be5xf4 Qf5h3+ Qe7h7 Qh3xh7+ Kh8xh7 g2g3 Bf4e5 Rf1xf8 Rb8xf8 Rh1e1 Rf8f2 Re1xe3
   12/31/2008 11:27:58 AM, Time for this analysis: 10:00:00, Rated time: 10:00:00

0 of 1 matching moves
12/31/2008 11:27:58 AM, Total time: 10:00:14 AM
Rated time: 10:00:00 = 36000 Seconds

[Dann Corbit]

Additional analysis can be found in the Rybka forum:
http://rybkaforum.net/cgi-bin/rybkaforu ... pid=131826

[michiguel]

Additional analysis can be found in the Rybka forum:
http://rybkaforum.net/cgi-bin/rybkaforu ... pid=131826

I have no question in my mind that e5 is THE move. It just needs to be compared with the option Bf2. Black is in very good positional shape after blocking e5. Nimzovich will be delighted.

It would be interesting to see a match play between two strong engines starting with e5 in one hand, and Bf2 on the other.

Miguel

[Spock]

I had a power outage but restarted the analysis.

here, Quad Hiarcs 12.1 finished depth 22 after 9 hrs, but then after 15 more hrs is still working and and hasn't output anything for depth 23

[d] rnbq1rk1/pp4bp/3pP3/2pP3n/2P5/2NBp3/PPQ1N1PP/R3K2R b KQ -

So after 24+ hrs and 134 billion nodes.. after e5 and e6, according to Hiarcs anyway the bishop sacrifice puts white in a marginally worse position than if it had saved its bishop

Code: Select all

  9/26	 0:00 	-1.00 	1...Nf6 (936.081) 1268
  9/26	 0:00 	-1.00 	1...Nf6 2.O-O Na6 3.a3 Bh6 4.Nf4 Bxf4 5.Rxf4 (941.850) 1268
 10/26	 0:00 	-0.75--	1...Nf6 2.O-O (1.166.875) 1213
 10/33	 0:01 	-0.57 	1...Nf6 2.O-O Na6 3.a3 Qc7 4.Nf4 Bh6 5.Qe2 Qb6 6.Qxe3 Qxb2 (1.344.161) 1196
 10/33	 0:01 	-0.57 	1...Bxc3+ (1.359.352) 1196
 10/33	 0:02 	-0.58 	1...Bxc3+ 2.Nxc3 Kg7 3.Bxh7 Qh4+ 4.g3 Qg4 5.Bd3 (3.286.381) 1334
 10/33	 0:02 	-0.59 	1...Kh8 (3.531.133) 1338
 10/33	 0:02 	-0.84 	1...Kh8 2.O-O-O Rf2 3.Rhf1 Rxg2 4.Bxh7 Bxc3 5.bxc3 (3.701.818) 1338
 11/33	 0:03 	-0.60 	1...Kh8 2.O-O-O Rf2 3.Rhf1 Qe7 4.Rxf2 exf2 5.Ne4 (5.174.415) 1358
 12/34	 0:07 	-0.85++	1...Kh8 (10.433.911) 1402
 12/34	 0:07 	-0.85 	1...Kh8 2.O-O-O Rf2 3.Rdf1 (11.178.049) 1399
 13/34	 0:11 	-0.78 	1...Kh8 2.O-O-O Rf2 3.Ne4 Rxg2 4.Rdg1 Rxg1+ 5.Rxg1 h6 6.N4c3 Qh4 7.Nb5 Qe7 8.Bg6 Nf6 9.Qd3 a6 (17.254.545) 1441
 14/36	 0:20 	-0.53--	1...Kh8 2.O-O-O (29.540.998) 1469
 14/36	 0:20 	-0.53 	1...Kh8 2.O-O-O Rf2 3.Ne4 Rxg2 4.Rdg1 Rxg1+ 5.Rxg1 h6 6.N4c3 Qh4 7.Nb5 Qe7 8.Bg6 Nf6 9.Qd3 a6 10.Na3 b5 (30.538.762) 1470
 14/36	 0:31 	-0.54 	1...Bxc3+ (46.666.619) 1475
 14/40	 0:52 	-0.55 	1...Bxc3+ 2.Nxc3 Na6 3.a3 Kh8 4.g3 Qg5 5.Ne4 Qe5 6.Qc3 (78.029.164) 1488
 15/45	 2:08 	-0.51 	1...Bxc3+ 2.bxc3 Qh4+ 3.g3 Qe7 4.Bf5 Nd7 5.exd7 (188.551.513) 1468
 15/45	 2:10 	-0.52 	1...Kh8 (190.925.994) 1467
 15/45	 2:33 	-0.79 	1...Kh8 2.Bf5 Qg5 (225.208.805) 1466
 16/45	 3:13 	-0.73 	1...Kh8 2.Bf5 Be5 3.g3 Qg5 4.Bxh7 Nf6 5.Bd3 Na6 6.O-O-O Nb4 7.Qb1 Nxd3+ (284.270.524) 1468
 17/45	 4:43 	-0.57 	1...Kh8 2.Bf5 Be5 3.O-O Qg5 4.Bxh7 Rf2 5.Rxf2 exf2+ 6.Kf1 Nf6 7.Ne4 Qh5 8.Nxf6 (415.642.922) 1465
 17/45	 7:08 	-0.58 	1...Rf2 (631.270.212) 1473
 17/45	 7:16 	-0.58 	1...Rf2 2.Bxh7+ Kh8 3.g3 Bxc3+ 4.bxc3 Qg5 5.O-O-O Nf6 6.Bd3 (642.570.621) 1471
 18/47	12:52 	-0.35 	1...Rf2 2.Bxh7+ Kh8 3.g3 Na6 4.Be4 Qg5 5.a3 Nf6 6.Nd1 (1.136.288.646) 1470
 18/47	13:11 	-0.36 	1...Kh8 (1.162.435.392) 1468
 18/47	15:40 	-0.43 	1...Kh8 2.Bf5 Qh4+ 3.g3 Qxc4 4.e7 Re8 5.Bxc8 Na6 6.O-O Raxc8 7.Qf5 Nb4 8.Qxh5 Rxe7 9.Rf4 (1.378.424.799) 1465
 18/49	16:51 	-0.44 	1...Bxc3+ (1.487.515.400) 1470
 18/52	25:24 	-0.44 	1...Bxc3+ 2.Nxc3 (2.272.078.607) 1490
 19/54	48:24 	-0.24 	1...Bxc3+ 2.Nxc3 Na6 3.Rf1 Kh8 4.Nd1 Rxf1+ 5.Bxf1 (4.392.505.395) 1512
 19/54	48:57 	-0.25 	1...Kh8 (4.439.833.510) 1511
 19/54	58:45 	-0.35 	1...Kh8 2.Bxh7 Rf2 3.g3 Na6 4.Be4 Qg5 5.a3 Nf6 6.Nd1 (5.319.581.383) 1508
 19/55	71:34 	-0.36 	1...Na6 (6.449.175.213) 1501
 19/55	82:30 	-0.36 	1...Na6 2.Bxh7+ Kh8 3.Bf5 (7.411.711.282) 1497
 20/55	96:32 	-0.11--	1...Na6 2.Bxh7+ (8.628.281.452) 1489
 20/62	119:33 	+0.03 	1...Na6 2.Bxh7+ Kh8 3.Bf5 Qg5 4.O-O (10.821.973.725) 1508
 20/62	120:34 	+0.02 	1...Kh8 (10.909.672.381) 1507
 20/62	140:20 	-0.58 	1...Kh8 2.Bf5 Qh4+ 3.g3 Qxc4 4.O-O Na6 5.Bxh7 Rf2 6.Rxf2 exf2+ 7.Kg2 Qg4 8.Qf5 Qxf5 (12.659.523.532) 1503
 21/62	193:33 	-0.34 	1...Kh8 2.Bf5 Be5 3.O-O Qg5 4.Bxh7 (17.399.663.587) 1498
 21/62	233:56 	-0.35 	1...Rf2 (21.095.456.167) 1502
 21/62	267:35 	-0.35 	1...Rf2 2.Bxh7+ Kh8 3.Qg6 Qh4 4.g3 (24.281.713.582) 1512
 22/62	481:59 	-0.10 	1...Rf2 2.Bxh7+ Kh8 3.Qg6 Qh4 4.g3 Nxg3 5.Qxg3 Qxh7 6.Nf4 Bxe6 7.Ng6+ Kg8 8.Ne7+ Kf8 9.Ng6+ (44.133.146.626) 1526
 22/62	496:03 	-0.11 	1...Kh8 (45.402.302.427) 1525
 22/62	575:37 	-0.17 	1...Kh8 2.Bf5 Qh4+ 3.g3 Qxc4 4.O-O (52.402.207.254) 1517
best move: Kg8-h8 time: 1496:26.890 min  n/s: 1.500.495  nodes: 134.723.477.861 

[Dann Corbit]

Additional analysis can be found in the Rybka forum:
http://rybkaforum.net/cgi-bin/rybkaforu ... pid=131826

I have no question in my mind that e5 is THE move. It just needs to be compared with the option Bf2. Black is in very good positional shape after blocking e5. Nimzovich will be delighted.

It would be interesting to see a match play between two strong engines starting with e5 in one hand, and Bf2 on the other.

Miguel

I think that most strong engines will not understand the correct plan at even 40/2hrs. Having the right move is not good enough. The correct plan of action to accompany it is everything.

[Alessandro Damiani]

I found the game in which R. Knaak played e5: http://www.chessgames.com/perl/chessgame?gid=1291177

[diep]

From a German computer chess book (R. Knaak and others):

[D]rnbq1rk1/pp4bp/3p4/2pP3n/2P1Pp2/2NBB3/PPQ1N1PP/R3K2R w KQ - 0 1

Best move: e5 with follow-up e6 immobilising black's queen side.

I wonder if this can be solved with todays engines and hardware. Have fun!

Hi,

As a chessplayer I feel the real question is whether after e5 fxe3 the position is a draw for white, or maybe at least a draw. If it is, then e5 is the best move, because without e5, white has a disastreous losing position (pawn up or not).

I also feel that Velomirowicz played really bad after e5. First of all he didn't take on e5. What computers of course see perfectly fine is that after e5-e6, black has moves like Nc6 which are difficult to capture for white. Computer can calculate that perfectly fine. I doubt Velimirowicz could.

We cannot compare tactics of today with back then. A todays 2600 rated GM like Erwin l'Ami, playing openings from back then, would get handsdown world champion with the skills and bugfree tactics he plays with now, against players from 1972 in the year 1972 (that includes Fischer of course), simply because of the improved tactics from todays GM's and all the positional knowledge they have nowadays, which was more scarce back then.

It would be a mistake to say that only computers improved.

Doing a sacrafice like this against a strong player nowadays is a lot tougher also than back then. What hasnt changed however is the reaction of most players after a sacrafice. Many react total wrong, when you compare that to how computer reacts. The computer has given a dimension to chess extra there.

Because this game has been won by white, probably the sacrafice gets mentionned. If the black player had taken on e3 and drawn the game with moves like Nc6 i doubt we would have seen this great move in a diagram now.

The big question is whether white has a draw or at least a draw after e5. If black plays for a win after e5 fxe3, then things change of course. In nowadays chess it is better to not give away a piece when you defend.

Vincent