KomodoDragon brilliancy Ruy Lopez - Marshall! A marshall reborn?

[MikeGL]

Prabably 21. Bf3? was the blunder as suggested my droidfish running 10-15 seconds per position.

Maybe there are other alternatives but I think 21.Bf3 move doens't deserve a "?" tag because it is also a strong move.

Code: Select all

29/45  +0.21  Qe1 Bf5 Bf3 Rg8 Re5 Bh3 Nf1 Qg7 Ng3 fxg3 hxg3 Bxe5 Qxe5 Rae8 Qxg7+ Rxg7 Be3 Rg6 a4 Bg4 Bg2 Bf5 axb5 axb5 Ra7 Kg7 d5 cxd5 Bd4+ Kg8 Bxd5 Be6 
29/12   0.00  Bf3 Rg8 Qd1 Bh3 Re1 f5 c4 Qg5 Rg1 Qh4 Re1
29/51  -1.07  Qe2 Rg8 Re8 Bg4 Rxg8+ Rxg8 Qxg4 Rxg4 Bxg4 Qh4 Bf3 Qxf2 Bxc6 Qe1+ Kg2 Qe2+ Kh1 b4 Bf3 Qd3 Kg2 bxc3 bxc3 Qxc3 Rb1 a5 Kf1 Bb4 a3 Bxa3 Bxa3 

The error is most likely within the series of 5 moves from move 21. to 26. If you send this pgn to Bryan-Stockfish, he may do backward forward analysis and microscope the blunder in more detail.

That is possible, or maybe KomodoDragon just killed a specific line inRuy Lopez - Marshall after Nf4!.
Because I checked and saw stockfish, nemorino, rubichess, slowchess were all victims by KomodoDragon in this line.
Maybe this is a forced win after Nf4! by black, but deeper analysis is required.

[d]r1b2rk1/5p1p/p1pb4/1p1n2pq/3PR3/1BP3P1/PP1N1P1P/R1B2QK1 b - - 3 17

GM-GM games in my database shows:
18 draws
16 white wins
11 black wins

engine-engine games in my database shows
6 black wins all by KomodoDragon

but note that Nf4 was not played before by humans nor by engines,
the previous tries were Bf5, f5, Bh3 and Nf6 on this position mostly by Armenian super GMs

[MikeGL]

Prabably 21. Bf3? was the blunder as suggested my droidfish running 10-15 seconds per position.

Maybe there are other alternatives but I think 21.Bf3 move doens't deserve a "?" tag because it is also a strong move.

Code: Select all

29/45  +0.21  Qe1 Bf5 Bf3 Rg8 Re5 Bh3 Nf1 Qg7 Ng3 fxg3 hxg3 Bxe5 Qxe5 Rae8 Qxg7+ Rxg7 Be3 Rg6 a4 Bg4 Bg2 Bf5 axb5 axb5 Ra7 Kg7 d5 cxd5 Bd4+ Kg8 Bxd5 Be6 
29/12   0.00  Bf3 Rg8 Qd1 Bh3 Re1 f5 c4 Qg5 Rg1 Qh4 Re1
29/51  -1.07  Qe2 Rg8 Re8 Bg4 Rxg8+ Rxg8 Qxg4 Rxg4 Bxg4 Qh4 Bf3 Qxf2 Bxc6 Qe1+ Kg2 Qe2+ Kh1 b4 Bf3 Qd3 Kg2 bxc3 bxc3 Qxc3 Rb1 a5 Kf1 Bb4 a3 Bxa3 Bxa3 

The error is most likely within the series of 5 moves from move 21. to 26. If you send this pgn to Bryan-Stockfish, he may do backward forward analysis and microscope the blunder in more detail.

That is possible, or maybe KomodoDragon just killed a specific line inRuy Lopez - Marshall after Nf4!.
Because I checked and saw stockfish, nemorino, rubichess, slowchess were all victims by KomodoDragon in this line.
Maybe this is a forced win after Nf4! by black, but deeper analysis is required.

[d]r1b2rk1/5p1p/p1pb4/1p1n2pq/3PR3/1BP3P1/PP1N1P1P/R1B2QK1 b - - 3 17

GM-GM games in my database shows:
18 draws
16 white wins
11 black wins

engine-engine games in my database shows
6 black wins all by KomodoDragon

but note that 17...Nf4 for black was not played before by humans nor by engines prior to the appearance of KomodoDragon,
the previous tries were 17...Bf5, 17...f5, 17...Bh3 and 17...Nf6 on this position mostly by Armenian super GMs

[Ozymandias]

I once thought Marshall was already analyzed to death and
the consensus was that this openning just leads to draw.

That consensus doesn't include opening expert (sic) Tsvetkov's opinion:

the Marshall might pretty well be busted

In the game you post, white already plays weak with 15. Re4, so all bets are off from that point forward.

[M ANSARI]

Wow ... incredible game ... thanks for posting it!

[Andrew]

Prabably 21. Bf3? was the blunder as suggested my droidfish running 10-15 seconds per position.

Maybe there are other alternatives but I think 21.Bf3 move doens't deserve a "?" tag because it is also a strong move.

Code: Select all

29/45  +0.21  Qe1 Bf5 Bf3 Rg8 Re5 Bh3 Nf1 Qg7 Ng3 fxg3 hxg3 Bxe5 Qxe5 Rae8 Qxg7+ Rxg7 Be3 Rg6 a4 Bg4 Bg2 Bf5 axb5 axb5 Ra7 Kg7 d5 cxd5 Bd4+ Kg8 Bxd5 Be6 
29/12   0.00  Bf3 Rg8 Qd1 Bh3 Re1 f5 c4 Qg5 Rg1 Qh4 Re1
29/51  -1.07  Qe2 Rg8 Re8 Bg4 Rxg8+ Rxg8 Qxg4 Rxg4 Bxg4 Qh4 Bf3 Qxf2 Bxc6 Qe1+ Kg2 Qe2+ Kh1 b4 Bf3 Qd3 Kg2 bxc3 bxc3 Qxc3 Rb1 a5 Kf1 Bb4 a3 Bxa3 Bxa3 

Mike was the above analysis with Stockfish 12 or DragonKomodo?
Try the same after 21 Bf3 Rg8, for several minutes on three variation mode.
You should find that both these engines start on 22. Qd1 but eventually switch to 22. Bg2 (however even this goes
further negative with time).

21 Qe1 maybe holds the draw, needs longer analysis

From memory a lot of Stefan's games are single core for his ratings lists. But whatever the number of cores
or time control, in games there will always be positions which need just that little bit extra. Which
makes games like this fun!

Andrew

[mwyoung]

Prabably 21. Bf3? was the blunder as suggested my droidfish running 10-15 seconds per position.

Maybe there are other alternatives but I think 21.Bf3 move doens't deserve a "?" tag because it is also a strong move.

Code: Select all

29/45  +0.21  Qe1 Bf5 Bf3 Rg8 Re5 Bh3 Nf1 Qg7 Ng3 fxg3 hxg3 Bxe5 Qxe5 Rae8 Qxg7+ Rxg7 Be3 Rg6 a4 Bg4 Bg2 Bf5 axb5 axb5 Ra7 Kg7 d5 cxd5 Bd4+ Kg8 Bxd5 Be6 
29/12   0.00  Bf3 Rg8 Qd1 Bh3 Re1 f5 c4 Qg5 Rg1 Qh4 Re1
29/51  -1.07  Qe2 Rg8 Re8 Bg4 Rxg8+ Rxg8 Qxg4 Rxg4 Bxg4 Qh4 Bf3 Qxf2 Bxc6 Qe1+ Kg2 Qe2+ Kh1 b4 Bf3 Qd3 Kg2 bxc3 bxc3 Qxc3 Rb1 a5 Kf1 Bb4 a3 Bxa3 Bxa3 

The error is most likely within the series of 5 moves from move 21. to 26. If you send this pgn to Bryan-Stockfish, he may do backward forward analysis and microscope the blunder in more detail.

That is possible, or maybe KomodoDragon just killed a specific line inRuy Lopez - Marshall after Nf4!.
Because I checked and saw stockfish, nemorino, rubichess, slowchess were all victims by KomodoDragon in this line.
Maybe this is a forced win after Nf4! by black, but deeper analysis is required.

[d]r1b2rk1/5p1p/p1pb4/1p1n2pq/3PR3/1BP3P1/PP1N1P1P/R1B2QK1 b - - 3 17

GM-GM games in my database shows:
18 draws
16 white wins
11 black wins

engine-engine games in my database shows
6 black wins all by KomodoDragon

but note that 17...Nf4 for black was not played before by humans nor by engines prior to the appearance of KomodoDragon,
the previous tries were 17...Bf5, 17...f5, 17...Bh3 and 17...Nf6 on this position mostly by Armenian super GMs

No. The line is good. Something was wrong with Stockfish 12, or it just plain blundered. As the current Stockfish saw the error instantly. And would not have lost the game.

[Ajedrecista]

Hello:

ok I just checked in my database of Human-Human GM games, 17...Nf4! move is not found, maybe this is a Novelty by engines.
Even SF 12 cannot consider this move (17...Nf4!!) . I wonder if KomodoDragon is NNUE or pure NN similar to Lc0, because this is a very different move which is a bit difficult for A/B engines.
[d]r1b2rk1/5p1p/p1pb4/1p1n2pq/3PR3/1BP3P1/PP1N1P1P/R1B2QK1 b - - 3 17
bm Nf4

I did not find games with 17.- ..., Nf4 in this exact position, but ..., Nf4; gxf4, gxf4 looks like a thematic sacrifice just like RxN (..., Rxc3) in the Sicilian Dragon. There is a somewhat similar idea in Ernst 0 - 1 Hebden, Gausdal 1987:

Thomas Ernst 0 - 1 Mark Hebden. Arnold Cup (1987), Gausdal (NOR).

[pgn]
[Event "Arnold Cup"]
[Site "Gausdal NOR"]
[Date "1987.??.??"]
[EventDate "?"]
[Round "?"]
[Result "0-1"]
[White "Thomas Ernst"]
[Black "Mark Hebden"]
[ECO "C89"]
[WhiteElo "?"]
[BlackElo "?"]
[PlyCount "68"]

1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6 5. O-O Be7 6. Re1 b5
7. Bb3 O-O 8. c3 d5 9. exd5 Nxd5 10. Nxe5 Nxe5 11. Rxe5 c6
12. d4 Bd6 13. Re1 Qh4 14. g3 Qh3 15. Re4 g5 16. Qf1 Qh5
17. Qe2 Qg6 18. Re8 Bf5 19. Rxa8 Rxa8 20. Nd2 Bd3 21. Qe1 Nf4
22. gxf4 gxf4+ 23. Kh1 Kh8 24. Qg1 Qf6 25. f3 Re8 26. a4 Qh4
27. Ne4 Rg8 28. Nf2 Rxg1+ 29. Kxg1 Qg5+ 30. Kh1 Bf1 31. Ng4 h5
32. Bd2 Be2 33. Ne5 Bxe5 34. Rf1 Bxf1 0-1
[/pgn]

Other games involving this knight sacrifice at some point around move 20 are:

Smolenskij - Heffner. Corr. 1985. {17.- Bd2?, Bf5; 18.- Re1, Bh3; 19.- Qe2, Bg4; 20.- Qf1, Rae8; 21.- Na3, Bh3!; 22.- Qd3, Nf4! -+}.

Carlsson ½-½ Pedersen. Danish Junior Ch., Aarhus 1993. {16.- Qf3, Bf5; 17.- Bc2, Nf4?! Draw in 55 moves after white blundered in move 53}.

References of the three games found thanks to:

· C89 Marshall Attack, Chess Informant by Viswanathan Anand. © 1993.
· The Marshall Attack, incorporating the anti-Marshall lines, by Bodgan Lalić. © 2003.

There are probably more games with this ..., Nf4; PxN, PxP idea.

Regards from Spain.

Ajedrecista.

[JohnW]

I tried analyzing the position with a variety of engines and only Komodo Dragon considers Nf4 and does it almost immediately.

[Vinvin]

Prabably 21. Bf3? was the blunder as suggested my droidfish running 10-15 seconds per position.

Maybe there are other alternatives but I think 21.Bf3 move doens't deserve a "?" tag because it is also a strong move.

Code: Select all

29/45  +0.21  Qe1 Bf5 Bf3 Rg8 Re5 Bh3 Nf1 Qg7 Ng3 fxg3 hxg3 Bxe5 Qxe5 Rae8 Qxg7+ Rxg7 Be3 Rg6 a4 Bg4 Bg2 Bf5 axb5 axb5 Ra7 Kg7 d5 cxd5 Bd4+ Kg8 Bxd5 Be6 
29/12   0.00  Bf3 Rg8 Qd1 Bh3 Re1 f5 c4 Qg5 Rg1 Qh4 Re1
29/51  -1.07  Qe2 Rg8 Re8 Bg4 Rxg8+ Rxg8 Qxg4 Rxg4 Bxg4 Qh4 Bf3 Qxf2 Bxc6 Qe1+ Kg2 Qe2+ Kh1 b4 Bf3 Qd3 Kg2 bxc3 bxc3 Qxc3 Rb1 a5 Kf1 Bb4 a3 Bxa3 Bxa3 

The error is most likely within the series of 5 moves from move 21. to 26. If you send this pgn to Bryan-Stockfish, he may do backward forward analysis and microscope the blunder in more detail.

SugaR.AI.ICCF.1 thinks Bf3 is not good and prefere Qe1!

3 best moves :

Code: Select all

FEN: r1b2r1k/5p1p/p1pb3q/1p6/3PRp2/2P5/PP1N1P1P/R1BB1Q1K w - - 4 21

SugaR.AI.ICCF.1.00.popcnt:

 33/63	27:20	6 960 592 068	4 242 038	-0,88	21.Bf3 Rg8 22.Bg2 Bf5 23.Re1 Qh4 24.b3 Rg7 25.d5 f6 26.Ba3 Bxa3 27.Qe2 Bc5 28.Nf3 Qg4 29.Rg1 cxd5 30.Nd4 Bxd4 31.Qxg4 Bxg4 32.cxd4 f3 33.Bf1 Bf5 34.h3 Be4 35.Rxg7 Kxg7 36.a4 bxa4 37.bxa4 a5 38.Kh2 Kg6 39.Kg3
 34/106	27:20	6 960 592 068	4 242 038	-0,22	21.Qe2 Rg8 22.Re8 Bg4 23.Rxg8+ Rxg8 24.Qxg4 Rxg4 25.Bxg4 Qh4 26.Bf3 Qxf2 27.Bxc6 h5 28.Nf3 Qf1+ 29.Ng1 h4 30.Bf3 h3 31.a4 bxa4 32.Rxa4 Qxc1 33.Rxa6 Be7 34.Rh6+ Kg8 35.Rxh3 Qxb2 36.Bg2 Ba3 37.Rf3 Qd2 38.Nh3 Bb2 39.Rf1 Bxc3 40.Rxf4 Qc1+ 41.Rf1 Qh6 42.Rf2 Bxd4 43.Rf3 Be5 44.Rf2
 34/62	27:20	6 960 592 068	4 242 038	+0,07	21.Qe1 Bf5 22.Re5 Bh3 23.Nf1 Qg6 24.Bf3 Bxe5 25.Qxe5+ f6 26.Qe4 Bxf1 27.Qxg6 hxg6 28.Bxf4 Bc4 29.Bxc6 Rad8 30.Be3 Bd5+ 31.Bxd5 Rxd5 32.a4 Kg7 33.Kg2 Rf5 34.axb5 axb5 35.Ra7+ Rf7 36.Bh6+ Kg8 37.Ra8+ Kh7 38.Bf8 Rg5+ 39.Kf3 Rf5+

[mwyoung]

Prabably 21. Bf3? was the blunder as suggested my droidfish running 10-15 seconds per position.

Maybe there are other alternatives but I think 21.Bf3 move doens't deserve a "?" tag because it is also a strong move.

Code: Select all

29/45  +0.21  Qe1 Bf5 Bf3 Rg8 Re5 Bh3 Nf1 Qg7 Ng3 fxg3 hxg3 Bxe5 Qxe5 Rae8 Qxg7+ Rxg7 Be3 Rg6 a4 Bg4 Bg2 Bf5 axb5 axb5 Ra7 Kg7 d5 cxd5 Bd4+ Kg8 Bxd5 Be6 
29/12   0.00  Bf3 Rg8 Qd1 Bh3 Re1 f5 c4 Qg5 Rg1 Qh4 Re1
29/51  -1.07  Qe2 Rg8 Re8 Bg4 Rxg8+ Rxg8 Qxg4 Rxg4 Bxg4 Qh4 Bf3 Qxf2 Bxc6 Qe1+ Kg2 Qe2+ Kh1 b4 Bf3 Qd3 Kg2 bxc3 bxc3 Qxc3 Rb1 a5 Kf1 Bb4 a3 Bxa3 Bxa3 

The error is most likely within the series of 5 moves from move 21. to 26. If you send this pgn to Bryan-Stockfish, he may do backward forward analysis and microscope the blunder in more detail.

SugaR.AI.ICCF.1 thinks Bf3 is not good and prefere Qe1!

3 best moves :

Code: Select all

FEN: r1b2r1k/5p1p/p1pb3q/1p6/3PRp2/2P5/PP1N1P1P/R1BB1Q1K w - - 4 21

SugaR.AI.ICCF.1.00.popcnt:

 33/63	27:20	6 960 592 068	4 242 038	-0,88	21.Bf3 Rg8 22.Bg2 Bf5 23.Re1 Qh4 24.b3 Rg7 25.d5 f6 26.Ba3 Bxa3 27.Qe2 Bc5 28.Nf3 Qg4 29.Rg1 cxd5 30.Nd4 Bxd4 31.Qxg4 Bxg4 32.cxd4 f3 33.Bf1 Bf5 34.h3 Be4 35.Rxg7 Kxg7 36.a4 bxa4 37.bxa4 a5 38.Kh2 Kg6 39.Kg3
 34/106	27:20	6 960 592 068	4 242 038	-0,22	21.Qe2 Rg8 22.Re8 Bg4 23.Rxg8+ Rxg8 24.Qxg4 Rxg4 25.Bxg4 Qh4 26.Bf3 Qxf2 27.Bxc6 h5 28.Nf3 Qf1+ 29.Ng1 h4 30.Bf3 h3 31.a4 bxa4 32.Rxa4 Qxc1 33.Rxa6 Be7 34.Rh6+ Kg8 35.Rxh3 Qxb2 36.Bg2 Ba3 37.Rf3 Qd2 38.Nh3 Bb2 39.Rf1 Bxc3 40.Rxf4 Qc1+ 41.Rf1 Qh6 42.Rf2 Bxd4 43.Rf3 Be5 44.Rf2
 34/62	27:20	6 960 592 068	4 242 038	+0,07	21.Qe1 Bf5 22.Re5 Bh3 23.Nf1 Qg6 24.Bf3 Bxe5 25.Qxe5+ f6 26.Qe4 Bxf1 27.Qxg6 hxg6 28.Bxf4 Bc4 29.Bxc6 Rad8 30.Be3 Bd5+ 31.Bxd5 Rxd5 32.a4 Kg7 33.Kg2 Rf5 34.axb5 axb5 35.Ra7+ Rf7 36.Bh6+ Kg8 37.Ra8+ Kh7 38.Bf8 Rg5+ 39.Kf3 Rf5+

Yes as I have said this is not the "Marshall! A marshall reborn?"