Amazing queen sacrifice!

Jack Lad · Post by **Jack Lad** » Mon Mar 09, 2009 10:01 am

Terry McCracken wrote:It's opening theory and this type of trading is often seen in GM games.

This is true as Eric Schiller explains:

The opening of this game is very popular and was the subject of a lot of theory. There are tons of games, at least 100 with the main line. So it was surely not improvisation. I haven't found the correct reference, but it should be in Pirc literature from ca. 1980. The game through move 14 was repeated just a few years ago.

What is impressive for Nigel is not the queen sac, already analyzed, but his carrying out of the final assault. The real work was in the middlegame.

It is sometimes known as "Three for the Lady". I am convinced that white is winning here and would be happy to challenge anyone to try to prove me wrong.

Eelco de Groot · Post by **Eelco de Groot** » Mon Mar 09, 2009 10:01 am

Certainly not Rybka but Blueberry would also play 7. exf6. It thinks long about Bxf7+ but rejects it so far:

[D]r1bqk2r/ppp1ppbp/3p1np1/4P3/2Bn4/2N5/PPP1QPPP/R1B1K1NR w KQkq -

Engine: Blueberry Beta 4 DM70 Build 373 (256 MB)
by F. Letouzey, T. Gaksch, E. de Groot

1/09 0:00 -3.93 1.exf6 Nxe2 2.fxg7 Ng3 (240)

1/14 0:00 -1.18 1.Bxf7+ Kxf7 2.Qc4+ Ne6 3.exf6 Bxf6 (1.150)

2/17 0:00 -1.18 1.Bxf7+ Kxf7 2.Qc4+ Ne6 3.exf6 Bxf6 (25.291)

2/22 0:00 -0.91 1.exf6 Nxe2 2.fxg7 Rg8 3.Bxe2 Rxg7
4.Nf3 Bf5 5.O-O Bxc2 6.Bb5+ Kf8 (232.799)

2/22 0:00 -0.91 1.exf6 Nxe2 2.fxg7 Rg8 3.Bxe2 Rxg7
4.Nf3 Bf5 5.O-O Bxc2 6.Bb5+ Kf8 (246.911)

2/23 0:00 -0.69 1.exf6 Nxe2 2.fxg7 Rg8 3.Bxe2 Rxg7
4.Nf3 Bf5 5.O-O Bxc2 6.Be3 e5 7.Bb5+ Kf8 (359.365)

3/26 0:00 -0.72 1.exf6 Nxe2 2.fxg7 Rg8 3.Ngxe2 Be6
4.Bxe6 fxe6 5.Bh6 (482.464)

4/26 0:01 -0.72 1.exf6 Nxe2 2.fxg7 Rg8 3.Ngxe2 Be6
4.Bxe6 fxe6 5.Bh6 (717.408) 600

5/30 0:01 -0.30 1.exf6 Bxf6 2.Qd2 Bf5 3.Bd3 Bxd3
4.cxd3 (1.053.509) 601

6/30 0:02 -0.69 1.exf6 Nxe2 2.fxg7 Rg8 3.Bxe2 Rxg7
4.Nf3 Bf5 5.O-O Bxc2 6.Be3 e5 7.Bb5+ Kf8 (1.387.915) 617

7/39 0:07 -0.53 1.exf6 Nxe2 2.fxg7 Rg8 3.Bxe2 Rxg7
4.Be3 Bf5 5.O-O-O e5 6.Kb1 a5 7.Nf3 (4.863.016) 621

8/45 0:15 -0.40 1.exf6 Nxe2 2.fxg7 Rg8 3.Bxe2 Bf5
4.Nf3 Rxg7 5.Bh6 Rg8 6.O-O-O a5
7.Nd5 e5 8.Bb5+ c6 (9.480.809) 602

9/45 0:36 -0.61 1.exf6 Nxe2 2.fxg7 Rg8 3.Bxe2 Rxg7
4.Be3 c5 5.Nf3 Kf8 6.O-O-O Qa5 7.Bh6 Be6
8.Ng5 Rc8 9.Bxg7+ Kxg7 (21.441.599) 590

10/45 1:07 -0.58 1.exf6 Nxe2 2.fxg7 Rg8 3.Bxe2 Rxg7
4.Be3 c5 5.Nf3 h5 6.O-O Bd7 (40.716.630) 603

11/45 1:25 -0.58 1.exf6 Nxe2 2.fxg7 Rg8 3.Bxe2 Rxg7
4.Be3 c5 5.Nf3 h5 6.O-O Bd7 (52.244.130) 609

12/45 2:41 -0.54 1.exf6 Nxe2 2.fxg7 Rg8 3.Bxe2 Rxg7
4.Be3 c5 5.Nf3 Kf8 6.O-O Bf5 7.Bh6 f6
8.Rfd1 Bxc2 (100.215.829) 620

13/51 17:23 -0.61 1.exf6 Nxe2 2.fxg7 Rg8 3.Bxe2 Rxg7
4.Nf3 Bf5 5.Bh6 Rg8 6.O-O-O c6 7.Be3 Qa5
8.Nd4 O-O-O 9.Kb1 d5 10.Nxf5 gxf5 (615.133.185) 589

14/53 37:09 -0.61 1.exf6 Nxe2 2.fxg7 Rg8 3.Bxe2 Rxg7
4.Nf3 Bf5 5.Bh6 Rg8 6.O-O-O c6 7.Be3 Qa5
8.Nd4 O-O-O 9.Kb1 d5 10.Nxf5 gxf5 (1.280.984.188) 574

Eelco

Jack Lad · Post by **Jack Lad** » Mon Mar 09, 2009 10:02 am

Bxf7+ looks strong but is actually as losing move imo.

Jack Lad · Post by **Jack Lad** » Mon Mar 09, 2009 10:04 am

Mike S. wrote:White immediatly - within six plies if we include 9...Rxg7 - gets three minor pieces for queen+pawn (and a HUGE developement advantage); the rest of the game is amusing. So this is not a queen sacrifice but a much smaller sacrifice (3*3=9, 9+1=10 by simple material counting). If so much material comes back "directly", then I don't think it makes sense to call it a queen sacrifice.

I agree.

Eelco de Groot · Post by **Eelco de Groot** » Mon Mar 09, 2009 10:44 am

Jack Lad wrote:Bxf7+ looks strong but is actually as losing move imo.

You may be right Jack. I just looked the variation up in my copy of NCO and John Nunn who covered the Pirc here as an expert on this opening, recommends 6...Ng4 as stronger than what Richard Miles played. Never heard of Richard Miles. I only know of John Miles

Music

Music was my first love and it will be my last
Music of the future and music of the past
o live without my music would be impossible do
In this world of troubles my music pulls me through.

Music was my first love and it will be my last
Music of the future and music of the past
And music of the past and music of the past.

Music was my first love and it will be my last
Music of the future and music of the past
To live without my music would be impossible do
In this world of troubles my music pulls me through.

John (Nunn, not Miles) gives the same variation after 6...Nxd4 as played in this game and thinks after 11... Be6! (instead of 11... e6) it is ∞, unclear. No mention of 7. Bxf7+ as a viable alternative.

Bluebery thinks this is about half a pawn worse than 7. exf6.

r1bqk2r/ppp1ppbp/3p1np1/4P3/2Bn4/2N5/PPP1QPPP/R1B1K1NR w KQkq -

Engine: Blueberry Beta 4 DM70 Build 373 (256 MB)
by F. Letouzey, T. Gaksch, E. de Groot

12 1:32 -0.56 1.exf6 Nxe2 2.fxg7 Rg8 3.Bxe2 Rxg7
4.Nf3 Bf5 5.Bh6 Rg8 6.O-O-O c6 7.Be3 Rb8 (55.042.760) 596

12 1:43 -1.17 1.Bxf7+ Kxf7 2.Qc4+ Be6 3.Qxd4 dxe5
4.Qd2 Qxd2+ 5.Bxd2 e4 6.O-O-O Rhd8
7.Nge2 Bf5 8.h3 Nd5 9.Nb5 e3 (61.686.039) 596

______________________________________________________

13 28:29 -0.56 1.exf6 Nxe2 2.fxg7 Rg8 3.Bxe2 Rxg7
4.Nf3 Bf5 5.Bh6 Rg8 6.O-O-O c6 7.Bg5 Qa5
8.Rhe1 Kd7 9.Kb1 (1.015.623.700) 592

13 30:26 -1.13 1.Bxf7+ Kxf7 2.Qc4+ Be6 3.Qxd4 dxe5
4.Qh4 Qd4 5.Qg3 Bg4 6.Nf3 Nh5 7.Ng5+ Kg8
8.Qe3 Nf4 9.O-O Rd8 10.Qxd4 exd4
11.Bxf4 dxc3 (1.083.241.939) 592

I could look up what John Nunn says elsewhere if I can find my copy of "The Complete Pirc", the bible on the subject!
It's a pity most of these precious volumes see few updates, it is too much work and too little demand I suppose, Nunn said as much when asked about any new work on NCO, the computers and databases are taking over and the new variations come at an ever faster pace. But we need GMs like John Nunn and opening experts like Jeroen Noomen to give us an overview and human insight

[Event "London"]
[Site "London"]
[Date "1976.??.??"]
[EventDate "?"]
[Round "?"]
[Result "1-0"]
[White "Nigel Short"]
[Black "Richard Miles"]
[ECO "B07"]
[WhiteElo "?"]
[BlackElo "?"]
[PlyCount "49"]

1.e4 d6 2.d4 Nf6 3.Nc3 g6 4.Bc4 Bg7 5.Qe2 Nc6 6.e5 Nxd4 7.exf6
Nxe2 8.fxg7 Rg8 9.Ngxe2 Rxg7 10.Bh6 Rg8 11.O-O-O e6 12.h4 Bd7
13.Ne4 f6 14.Nf4 Kf7 15.Rhe1 Re8 16.g4 a5 17.a3 b5 18.Ba2 Re7
19.g5 f5 20.Nf6 Bc8 21.Nxh7 c5 22.h5 gxh5 23.g6+ Kg8 24.Nf6+
Kh8 25.Nxe6 1-0

Sean Evans · Post by **Sean Evans** » Tue Mar 10, 2009 12:05 am

Jack Lad wrote:
Sean Evans wrote: Hi, I get the same results as Ray, and as S11 notes, Black is leading! So the exchange down is in Blacks favour. However, an interesting position though, thank you for sharing it
White's position is winning although black may be able to get a draw in a few variations.

Hi, based on computer chess software output, white is losing, not winning.

Eelco de Groot · Post by **Eelco de Groot** » Tue Mar 10, 2009 7:45 am

Eelco de Groot wrote:
Bluebery thinks this is about half a pawn worse than 7. exf6.

A second run with build 373, not clearing hash:

r1bqk2r/ppp1ppbp/3p1np1/4P3/2Bn4/2N5/PPP1QPPP/R1B1K1NR w KQkq -

Engine: Blueberry Beta 4 DM70 Build 373 (256 MB)
by F. Letouzey, T. Gaksch, E. de Groot

11 1:40 -0.46 1.exf6 Nxe2 2.fxg7 Rg8 3.Bxe2 Rxg7
4.Nf3 Bf5 5.Bh6 Rg8 6.O-O-O c6 7.h3 Qa5
8.g4 (58.124.659) 578

11 1:48 -1.18 1.Bxf7+ Kxf7 2.Qc4+ Be6 3.Qxd4 dxe5
4.Qh4 Qd4 5.Qxd4 exd4 6.Nf3 Bg4 7.Nxd4 Rhd8
8.f3 Bh5 9.Be3 Nd5 10.Nxd5 Rxd5 (62.980.249) 578
______________________________________________________________

12 3:10 -0.44 1.exf6 Nxe2 2.fxg7 Rg8 3.Bxe2 Rxg7
4.Nf3 Bf5 5.Bh6 Rg8 6.O-O-O c6 7.h3 b5
8.Nd4 Qb6 9.Nxf5 gxf5 (111.398.358) 583

12 3:21 -1.17 1.Bxf7+ Kxf7 2.Qc4+ Be6 3.Qxd4 dxe5
4.Qd2 Qxd2+ 5.Bxd2 e4 6.O-O-O Rhd8 7.Nge2 Bf5
8.h3 Nd5 9.Kb1 e3 (117.672.288) 583
______________________________________________________________

13 52:32 -0.82 1.exf6 Nxe2 2.fxg7 Rg8 3.Bxe2 Rxg7
4.Nf3 c6 5.Bh6 Rg8 6.O-O-O Bg4 7.h3 Bxf3
8.Bxf3 Qc7 9.Kb1 a5 10.Be3 d5 11.Rhe1 O-O-O
(1.742.238.992) 586

13 130:09 -1.05 1.Bxf7+ Kxf7 2.Qc4+ Be6 3.Qxd4 dxe5
4.Qa4 Qd4 5.Nf3 Qxa4 6.Ng5+ Ke8 7.Nxa4 Bd5
8.O-O Rd8 9.Nc5 Rd6 10.Be3 h6 11.Nf3 Bxf3 12.gxf3
(4.577.664.317) 586
______________________________________________________________

14 130:47 -0.52 1.exf6 Nxe2 2.fxg7 Rg8 3.Bxe2 Rxg7
4.Nf3 c6 5.Bh6 Rg8 6.O-O-O Bf5 7.Be3 d5
8.Kb1 Qa5 (4.593.136.948) 583

14 139:00 -1.11 1.Bxf7+ Kxf7 2.Qc4+ Be6 3.Qxd4 dxe5
4.Qh4 Qd4 5.Qxd4 exd4 6.Nf3 Bg4
7.Nxd4 c5 8.Nb3 b6 9.Bg5 h6 10.Bxf6 exf6
11.O-O Rhe8 12.Rfe1 (4.869.172.180) 583

On the basis of build 373 I made a few changes, going from null window search to PV node search there is less of a fall back in depth. Still it seems to be mostly the PV node search which has a very high branching factor. This build seemed to do better at first but then there was a 100 minute gap again before the next iteration for 1. Bxf7+ came through...

Then I expected a PV for Bxf7 but Blueberry started to process al other moves once more and the PV came only after that, with the gap between two PVs for the main moves almost at 120 minutes at ply 14 (164 min19sec - 47min16sec).

I wish I knew what exactly causes this. There is a random factor that is probably related to the engine not finding the hash results it needs for IID but this should affect the PV node search less. The effect is much more pronounced at higher depths which makes it difficult to test things. Lack the skill to make custom output tools

just looking at Shredder GUI outputs. Anyways at least here it finds the right move, still struggling with that position from Howard Exner where Blueberry totally oversees the Bxd6 move...

Output from build 375 going almost to 17 complete iterations:

[D]r1bqk2r/ppp1ppbp/3p1np1/4P3/2Bn4/2N5/PPP1QPPP/R1B1K1NR w KQkq -

Engine: Blueberry Beta 4 DM70 Build 375 (256 MB)
by F. Letouzey, T. Gaksch, E. de Groot

10 1:36 -0.52 1.exf6 Nxe2 2.fxg7 Rg8 3.Bxe2 Rxg7
4.Bh6 Rg8 5.O-O-O Bf5 6.Nf3 c6
7.Nd4 e5 8.Nxf5 gxf5 9.Rhg1 d5 (55.762.911) 584

10 3:48 -1.12 1.Bxf7+ Kxf7 2.Qc4+ Be6 3.Qxd4 dxe5
4.Qa4 Qd4 5.Nf3 Qxa4 6.Nxe5+ Ke8
7.Nxa4 Ne4 8.Nd3 Rd8 9.O-O Bd7
10.Ndc5 Nxc5 11.Nxc5 (133.352.178) 584
_____________________________________________________________

11 4:05 -0.40 1.exf6 Nxe2 2.fxg7 Rg8 3.Bxe2 Rxg7
4.Bh6 Rg8 5.O-O-O Bd7 6.Nf3 a5
7.Ng5 Bc6 8.Bc4 e6 (144.115.316) 588

11 4:44 -1.24 1.Bxf7+ Kxf7 2.Qc4+ Be6 3.Qxd4 dxe5
4.Qa4 Qd4 5.Qxd4 exd4 6.Nf3 Bd7
7.Nxd4 Ng4 8.Nf3 Bxc3+ 9.bxc3 Bc6
10.Ng5+ Kf6 11.O-O (167.304.928) 588
_____________________________________________________________

12 6:04 -0.44 1.exf6 Nxe2 2.fxg7 Rg8 3.Bxe2 Rxg7
4.Bh6 Rg8 5.O-O-O Bf5 6.Nf3 c6
7.Nd4 c5 (215.779.290) 600

12 13:11 -1.24 1.Bxf7+ Kxf7 2.Qc4+ Be6 3.Qxd4 dxe5
4.Qa4 Qd4 5.Qxd4 exd4 6.Nf3 Bd7
7.Nxd4 Ng4 8.Nf3 Bxc3+ 9.bxc3 Bc6
10.Ng5+ Kf6 11.O-O (475.196.263) 600
_____________________________________________________________

13 13:14 -0.52 1.exf6 Nxe2 2.fxg7 Rg8 3.Bxe2 Rxg7
4.Bh6 Rg8 5.O-O-O Bf5 6.Nf3 c6 7.Nd4 e5 (477.094.081) 591

13 39:29 -1.10 1.Bxf7+ Kxf7 2.Qc4+ Be6 3.Qxd4 dxe5
4.Qa4 Qd7 5.Nf3 Qxa4 6.Nxe5+ Ke8
7.Nxa4 Ne4 8.Nd3 Rd8 9.O-O Bd7
10.Nac5 Nxc5 11.Nxc5 Bc6 (1.401.466.923) 591
_____________________________________________________________

14 47:16 -0.68 1.exf6 Nxe2 2.fxg7 Rg8 3.Bxe2 Rxg7
4.Be3 Bf5 5.O-O-O f6 6.Nf3 d5 7.Nxd5 Kf7
8.Nxf6 Qb8 9.Nxh7 a5 10.Kb1 Rxh7
11.Bc4+ Kg7 (1.651.839.999) 579

14 164:19 -0.99 1.Bxf7+ Kxf7 2.Qc4+ Be6 3.Qxd4 dxe5
4.Qa4 Qd4 5.Qxd4 exd4 6.Nf3 Bd7
7.Nxd4 Ng4 8.Nf3 Bf5 9.Ng5+ Ke8
10.Nge4 Rd8 11.O-O Bxc3 12.Nxc3 Bxc2 (5.708.863.032) 579
_____________________________________________________________

15 179:21 -0.69 1.exf6 Nxe2 2.fxg7 Rg8 3.Bxe2 Rxg7
4.Be3 Bf5 5.O-O-O f6 6.g3 e5 7.Kb1 Rd7
8.Bf3 Qb8 9.g4 Bxc2+ 10.Kxc2 d5 (6.233.394.799) 607

15 360:51 -0.94 1.Bxf7+ Kxf7 2.Qc4+ Be6 3.Qxd4 dxe5
4.Qh4 Qd4 5.Qg3 Nh5 6.Qf3+ Bf5 7.Nge2 e4
8.Qe3 Qxe3 9.Bxe3 Rad8 10.h3 b5 11.O-O (13.143.926.783) 607
______________________________________________________________

16 464:32 -0.69 1.exf6 Nxe2 2.fxg7 Rg8 3.Bxe2 Rxg7
4.Bh6 Rg8 5.Nf3 c6 6.O-O-O Qa5 7.Kb1 Be6
8.Be3 Bf5 9.Ng5 Rb8 10.Nge4 g5
11.Nxg5 Bxc2+ 12.Kxc2 Qf5+ 13.Kc1 (16.587.796.696) 597

16 538:25 -1.04 1.Bxf7+ Kxf7 2.Qc4+ Be6 3.Qxd4 dxe5
4.Qa4 Qd4 5.Qxd4 exd4 6.Nf3 Bd7 7.Nxd4 Ng4
8.Nf3 h6 9.Bf4 Bc6 10.Bxc7 Bxc3+
11.bxc3 Rhc8 12.h3 Rxc7 13.hxg4 Rf8 (19.300.813.511) 597
______________________________________________________________

17 748:24 -0.73 1.exf6 Nxe2 2.fxg7 Rg8 3.Bxe2 Rxg7
4.Bh6 Rg8 5.Nf3 c6 6.O-O-O Qa5 7.Kb1 Be6
8.Be3 O-O-O 9.Nd4 Bd5 10.Bg4+ e6
11.Nxd5 cxd5 12.Bd2 b5 (26.731.489.648) 595

Difference between the two moves is less clear, and maybe the eval is very slightly going down for White after 7.exf6 but the quality of the PV node search is not actually that good, certainly not considering the number of cycles it takes. In general Blueberry's PV node search is more selective -because of the singular extensions, but there may be other factors- than the null window searches with which the other moves at the root are searched, in spite of using a much larger window! Original Fruit uses an infinite size α-β window even, for searching the first move, at every iteration. There must have been a reason for that

Sorry for incoherent output!
Eelco

Jack Lad · Post by **Jack Lad** » Tue Mar 10, 2009 1:02 pm

Eelco de Groot wrote:Difference between the two moves is less clear, and maybe the eval is very slightly going down for White after 7.exf6 but the quality of the PV node search is not actually that good, certainly not considering the number of cycles it takes. In general Blueberry's PV node search is more selective -because of the singular extensions, but there may be other factors- than the null window searches with which the other moves at the root are searched, in spite of using a much larger window! Original Fruit uses an infinite size α-β window even, for searching the first move, at every iteration. There must have been a reason for that

Sorry for incoherent output!
Eelco

Thanks for your analysis and comment Eelco - there was a famous English GM called Tony Miles who was mistakenly thought to be the black player in this game.

It is interesting that all engines seem to give the position as favourable to black after 7.exf6. This is because they probably overvalue the queen and also cannot see too deeply into the position due to the horizon effect. Black maybe able to get a draw but no better and imo this position is winning for white. I challenge anyone to prove me wrong!

BBauer · Post by **BBauer** » Tue Mar 10, 2009 2:52 pm

Again Stockfish, enjoy!

Code: Select all

FEN&#58; r1bqk2r/ppp1ppbp/3p1np1/4P3/2Bn4/2N5/PPP1QPPP/R1B1K1NR w KQkq - 0 7 

Stockfish_12_opt_my&#58;
   6	00&#58;00	      20.851	141.843	-0,86	Bc4xf7+ Ke8xf7 Qe2c4+ Bc8e6 Qc4xd4 d6xe5 Qd4a4 Kf7g8 Qa4h4
   7	00&#58;00	      33.385	189.687	-1,62	Bc4xf7+ Ke8xf7 Qe2c4+ Bc8e6 Qc4xd4 d6xe5 Qd4xd8 Ra8xd8 Ng1f3 Nf6d5 Nf3g5+ Kf7f6
   7	00&#58;00	      37.773	203.080	-0,41	e5xf6 Nd4xe2 f6xg7 Rh8g8 Ng1xe2 Rg8xg7 Bc1h6 Rg7g8 OO
   8	00&#58;00	      51.830	251.601	-0,66	e5xf6 Nd4xe2 f6xg7 Rh8g8 Ng1xe2 Rg8xg7 Bc1h6 Rg7g8 OO Bc8e6
   9	00&#58;00	      95.299	392.176	-1,07	e5xf6 Nd4xe2 f6xg7 Rh8g8 Ng1xe2 e7e5 Bc1h6 Qd8h4 Nc3d5 Bc8f5 Nd5xc7+ Ke8e7
  10	00&#58;00	     236.725	686.159	-0,68	e5xf6 Nd4xe2 f6xg7 Rh8g8 Ng1xe2 Rg8xg7 Bc1h6 Rg7g8 OO Bc8e6 Nc3d5 Be6xd5 Bc4xd5
  11	00&#58;00	     378.714	868.610	-0,76	e5xf6 Nd4xe2 f6xg7 Rh8g8 Ng1xe2 Rg8xg7 Bc1h6 Rg7g8 OO Bc8e6 Bc4d3 Be6f5 Nc3e4
  12	00&#58;00	     690.612	1.103.214	-0,76	e5xf6 Nd4xe2 f6xg7 Rh8g8 Ng1xe2 Rg8xg7 OO Bc8e6 Bc1h6 Rg7g8 Bc4d3 Be6f5 Nc3e4 g6g5
  13	00&#58;01	   1.418.432	1.336.882	-1,19	e5xf6 Nd4xe2 f6xg7 Rh8g8 Ng1xe2 Rg8xg7 OO e7e5 Nc3e4 Qd8h4 Ne2g3 h7h6 h2h3 Bc8e6 Bc4b5+ Ke8f8
  14	00&#58;02	   3.019.503	1.496.284	-1,21	e5xf6 Nd4xe2 f6xg7 Rh8g8 Ng1xe2 Rg8xg7 OO e7e5 Nc3e4 Qd8h4 Ne2g3 h7h6 Bc4b5+ Bc8d7 Bc1xh6 Bd7xb5 Bh6xg7 Bb5xf1 Ra1xf1
  15	00&#58;04	   6.284.571	1.610.602	-1,13	e5xf6 Nd4xe2 f6xg7 Rh8g8 Ng1xe2 Rg8xg7 OO Bc8e6 Bc1h6 Rg7g8 Bc4xe6 f7xe6 Nc3e4 c7c6 Ne2d4 Ke8d7 Ra1e1 Qd8b6
  16	00&#58;07	  12.926.254	1.672.435	-1,09	e5xf6 Nd4xe2 f6xg7 Rh8g8 Ng1xe2 Rg8xg7 OO Bc8e6 Bc4b3 Be6xb3 a2xb3 e7e5 Rf1d1 Ke8d7 Bc1e3 h7h5 Nc3e4 f7f6 Be3xa7
  17	00&#58;16	  27.887.002	1.714.856	-1,11	e5xf6 Nd4xe2 f6xg7 Rh8g8 Ng1xe2 Rg8xg7 OO Bc8e6 Bc4b3 Be6xb3 a2xb3 e7e5 Rf1d1 Ke8d7 Bc1e3 h7h5 Nc3e4 Qd8h4 Ne4c5+ Kd7c6 Ra1a4
  18	00&#58;52	  85.581.802	1.634.144	-1,15	e5xf6 Nd4xe2 f6xg7 Rh8g8 Ng1xe2 Rg8xg7 OO Bc8f5 Bc1h6 Rg7g8 Bh6g5 c7c6 Ne2g3 d6d5 Bc4b3 Qd8b6 Ra1e1 Bf5e6 Bg5e3 Qb6a6
  19	01&#58;44	 173.401.586	1.660.791	-1,07	e5xf6 Nd4xe2 f6xg7 Rh8g8 Ng1xe2 Rg8xg7 OO c7c6 Bc4b3 Bc8e6 Rf1d1 h7h5 Bc1h6 Rg7g8 Nc3e4 Be6xb3 a2xb3 Ke8d7 Bh6g5 Qd8b6 Ne2d4 d6d5
  20	03&#58;12	 321.886.012	1.678.474	-1,13	e5xf6 Nd4xe2 f6xg7 Rh8g8 Ng1xe2 Rg8xg7 OO c7c6 Bc4b3 d6d5 Rf1e1 g6g5 Ne2g3 Ke8f8 Bc1e3 Kf8g8 Ra1d1 e7e5 Ng3e4 Bc8g4 f2f3 Bg4f5
  21	07&#58;08	 717.957.393	1.675.822	-1,05	e5xf6 Nd4xe2 f6xg7 Rh8g8 Ng1xe2 Rg8xg7 OO c7c6 Bc4b3 d6d5 Rf1e1 g6g5 Bc1e3 Ke8f8 Be3c5 Kf8g8 Ne2d4 f7f6 Nd4e6 Bc8xe6 Re1xe6 b7b6 Bc5e3 Qd8c7

kind regards
Bernhard

Stephen Ham · Post by **Stephen Ham** » Tue Mar 10, 2009 6:25 pm

Jack Lad wrote:
Eelco de Groot wrote:Difference between the two moves is less clear, and maybe the eval is very slightly going down for White after 7.exf6 but the quality of the PV node search is not actually that good, certainly not considering the number of cycles it takes. In general Blueberry's PV node search is more selective -because of the singular extensions, but there may be other factors- than the null window searches with which the other moves at the root are searched, in spite of using a much larger window! Original Fruit uses an infinite size α-β window even, for searching the first move, at every iteration. There must have been a reason for that

Sorry for incoherent output!
Eelco
Thanks for your analysis and comment Eelco - there was a famous English GM called Tony Miles who was mistakenly thought to be the black player in this game.

It is interesting that all engines seem to give the position as favourable to black after 7.exf6. This is because they probably overvalue the queen and also cannot see too deeply into the position due to the horizon effect. Black maybe able to get a draw but no better and imo this position is winning for white. I challenge anyone to prove me wrong!

Hi Jack!

How are you, buddy?

I hear you championing White and challenging us to prove you wrong. OK, I might accept your challenge. But just so we challengers don't spin our wheels, please provide us with compelling evidence that White can even equalize.

I don't have the time to run an engine check. But as a human, I think Black is at least equal after the recommended ...Be6. Besides, other moves have been recommended for Black all through this line, and they looked good to me too.

So if we're going to go the the effort of accepting your challenge, Jack, please tell us what specific line you think looks so dandy for White. Otherwise, I think Black has at least a fully playable game.

All the very best,
Steve

Amazing queen sacrifice!

Re: Amazing queen sacrifice!

Re: Amazing queen sacrifice!

Re: Amazing queen sacrifice!

Re: Amazing queen exchange!

Re: Amazing queen sacrifice!

Re: Amazing queen sacrifice!

Re: Amazing queen sacrifice!

Re: Amazing queen sacrifice!

Re: Amazing queen sacrifice!

Re: Amazing queen sacrifice!