Time to consider the Accelerated Dragon?

parisestmagique wrote on 09/08/06 at 08:22:27:


But after 19...Qa6, I indicate 20.Nf4, so you cannot play Bxd5 However, I probably missed black's best try after 20.Nf4, namely 20...Bc4. Now 21.bxc4 is not clear at all, but white probably holds a decisive advantage after 21.g5 instead. For example, 21.g5 e5 22.Bh3 Rc7 23.gxf6 exf4 24.Qxf4 Be6 25.Bxe6 fxe6 26. Rdg1.

Scholar wrote on 09/08/06 at 04:32:39:


True, white may not even have that much after 14...h5, which is another argument in favor of h4-h5-hxg6, I guess. As far as I can tell, white gets a substantial advantage if black tries 12. h4 h5 13 Nd5. 

Quote:


After 21.cxd3, I imagine it will eventually become a 4 vs. 5 pawn ending on the kingside (or 3 vs. 4 if white has to spend too much time rounding up the second a-pawn), and I don't know if that's going to win. So I took another look at 21.Rxd3. The key difference here is that black loses the second a-pawn right away and that white's b-pawn is already a passer. Sure, white lacks the d-pawn, and black gets an annoying pawn on a2, but black has to do something fast in the center or the b-pawn just rolls all the way. Who knows?  

Quote:


I wouldn't mind a few complications if the result is not just an advantage, but a huge advantage Frankly, though, I personally find the analysis in the PGN conceptually simple compared to the h4-h5-hxg6 main lines.

Quote:


Thank you for your interest!

Has everybody already given up on 9.. Nxd4? I had hoped for some more response  

The thesis is that the analysis presented below represents an even more promising (and simple) way to meet 9.. Nxd4 than the often recommended 12 h4 Rfc8 13 h5 Qa5 14 hxg6. Now, here 14.. hxg6 15 a3 has practically been analysed to a white win, but black may still hang on with 14.. fxg6. Hence the verdict of the g4 + h4-h5-h6 plan is of huge theoretical interest

Below is new PGN with elaborate analysis of this plan. Just copy the PGN, click board in interface, and press ctrl + v, and the game is loaded (works at least in Fritz 9 interface).

After 16 h6, my main conclusions are:

Black is very close to being lost after 16.. Bf8 17 Nd5 as well as after 16.. Bh8 17 g5. The principled black continuations do indeed lead to lost positions, while the deviations lead to big white advantages.

16.. b4 is black's most realistic try in my view. I would really welcome some comments on the ending arising, maybe from players with experience in evaluating this kind of Dragon endings where black is down an exchange.

Throughout the analysis, I have tried to assess the positions at the end of the lines. Challenges to these assessments are very welcome, as well as ideas that may disclose flaws in my analysis. 

Ultimately, what is the verdict? Which plan against 9.. Nxd4 looks more promising for white? What would you prefer?   


[Event "3rd PAL/CSS Freestyle Tournament - Prel"]
[Site "playchess.com #069217"]
[Date "2006.06.17"]
[Round "5"]
[White "Hoshad"]
[Black "Flying Saucers"]
[Result "1-0"]
[ECO "B76"]
[WhiteElo "2245"]
[BlackElo "2401"]
[Annotator "Klump,Rasmus"]
[PlyCount "69"]
[EventDate "2006.06.17"]
[EventType "swiss (rapid)"]

1. Nc3 c5 2. e4 d6 3. Nf3 Nf6 4. d4 cxd4 5. Nxd4 g6 6. Be3 Bg7 7. f3 O-O 8. Qd2
Nc6 9. O-O-O Nxd4 10. Bxd4 Be6 11. Kb1 Qc7 12. g4 (12. h4 Rfc8 13. h5 Qa5 14.
hxg6 fxg6 (14... hxg6 15. a3 {
has practically been analysed to a loss for black.}) 15. a3 {Can black play
this position? When white is to choose how to punish black for playing 9...
Nxd4, it looks like he should compare his chances in this position vs. his
chances in the ending arising after 16...b4 in the game notes.}) 12... Rfc8 13.
h4 Qa5 (13... h5 {Not very attractive.}) 14. a3 Rab8 (14... h5 {Still not.})
15. h5 b5 16. h6 Bh8 (16... b4 {
I think this is black's only realistic hope for a draw now.} 17. Nb5 (17. Nd5
Nxd5 (17... Bxd5 18. hxg7 e5 19. Bxe5 dxe5 20. exd5 Qc5 {
is probably also playable.}) 18. hxg7 Nc3+ $1 19. Ka1 f6 {
Black is at least no worse.}) 17... Rxb5 (17... Bh8 18. g5 {Transposes to game.
} (18. Qxb4 $5)) 18. Bxb5 Qxb5 19. hxg7 bxa3 20. Qd3 Qxd3 (20... Qc6 $5 21. b3
(21. bxa3 $5 Bc4 22. Qd2 Qb5+ 23. Ka1 Qa6 24. Qe3 e5 25. Bb2 Rb8 $44) 21... a5
22. Rh2 (22. Qd2 $5 a4 23. Rc1 (23. Bxf6 exf6 24. Rxh7 Qxc2+ 25. Qxc2 Rxc2 $11)
23... Bxg4 (23... axb3 24. cxb3 Qb5 25. Rxc8+ Bxc8 26. Qc3 $16) 24. fxg4 e5 25.
Ba1 Kxg7 $44) (22. Rc1 $5 Bd7) 22... a4 23. b4 Rb8 (23... a2+ 24. Ka1) 24. Qxa3
Qb5 25. Bc3 Kxg7 $16) 21. Rxd3 (21. cxd3 $5 Rb8 22. Rh2 (22. Rd2 $5 a5 23. Bc3
(23. Ka1 Rb4 24. Bc3 Rb3 $44) 23... a4 24. d4 axb2 25. d5 Bxg4 26. fxg4 Nxe4
27. Rc2 a3 28. Rd1 Nc5 $44) 22... Rb3 23. Bc3 {
I don't know if black has enough compensation.} (23. Bxa7 $6 Nd7 24. Bd4 Ne5
25. Bxe5 dxe5 26. Ka1 Kxg7 27. bxa3 Rxa3+ 28. Kb1 $44)) 21... a2+ 22. Ka1 Rxc2
23. Ra3 {I have spent a lot of time analysing this position with aid of Rybka.
At first, I thought black may be well on the way to a draw, but the simple
plan of Rxa7 and advancing the b-pawn proves very strong in many variations.
Black can counter in many different ways. In general, black is trying to
exchange as many center pawns as possible and rely on the a2-pawn as some kind
of fortress defence even when down on material (maybe even two exchanges). Due
to so many variations, I have not been able to reach a definitive conclusion,
but I think white is close to winning, and at least has very good practical
chances, also in aided games.}) (16... Bf8 {Supposedly the book move.} 17. Nd5
{The following analysis indicates that black has no adequate defense against
this move.} (17. Qg5 Nd7 $13) (17. Bxf6 b4 $13) 17... Qa4 {
The alternatives are not tempting.} (17... Qxd2 18. Nxf6+ exf6 19. Rxd2 {
I think black is lost. Some sample variations follows.} Be7 (19... d5 20. Bxa7
Ra8 21. exd5 Rd8 22. Be3 Bxd5 23. Bxb5 Bxf3 24. Rxd8 Rxd8 25. Rg1) (19... a5
20. Bxf6) (19... b4 20. axb4 d5 21. b5 (21. exd5)) 20. Bxa7 Ra8 21. Be3 (21.
Bb6 $5 b4 22. axb4 Ba2+ 23. Kc1 Ra4 (23... d5 24. Rd4 $5 (24. Bc5 {
transposes to variation after 21. Be3.}) 24... dxe4 25. Rxe4 Bb3 26. c3 Ra1+
27. Kd2 Bd6 28. Bg2 Ra2 29. Rb1 Be5 30. Kd3 Bd5 31. Bf1) 24. c3 Rxb4 25. Be3)
21... b4 22. axb4 Ba2+ 23. Kc1 d5 24. Bc5) (17... Qd8 18. Bxa7 (18. Nxf6+) (18.
Nf4)) (17... Qa6 18. Nf4) 18. b3 Qxa3 19. Bb2 Qc5 (19... Qa6 20. Nf4 Bd7 (20...
Qc6 21. Nxe6 (21. g5) 21... fxe6 22. g5 Ne8 $18 (22... Nh5 23. Rxh5 gxh5 24.
Bh3 $18)) (20... Nd7 21. Nxe6 fxe6 22. g5 $18) 21. Bxf6 exf6 {
The following line looks like a pretty forced win.} 22. Nd5 Be6 23. Nxf6+ Kh8
24. Qd4 Rb7 25. f4 Qc6 26. Rh2 Qc5 27. Qb2 Qc3 28. Qxc3 Rxc3 29. f5 Rf3 30. e5
gxf5 31. Bg2 Rf2 32. Bxb7 Rxh2 33. exd6 fxg4 (33... Bxh6 34. gxf5 Bxf5 35. d7
Bxd7 36. Rxd7 $18) 34. d7 Bxd7 35. Rxd7 Rxh6 36. Rxf7 Bg7 37. Nxg4 $18) 20. b4
Qc6 21. Rh2 {As in the game, Rh2 looks like white's crucial winning move.
White threatens g5 + Qd4.} Bxd5 (21... Nd7 22. Qd4 f6 23. g5 Bf7 (23... Ne5 24.
gxf6 Bxd5 25. exd5 Qb6 26. fxe7 Bxe7 27. Qe4 $18) (23... Bxd5 24. exd5 $40) 24.
Bh3 Ne5 (24... e5 25. Bxd7 exd4 26. Nxf6+ Kh8 27. Bxc6 Rxc6 28. Rhd2 $18) 25.
gxf6 Nxf3 26. Qf2 e6 27. Qxf3 exd5 28. exd5 Qb7 29. Bxc8 Rxc8 {
I doubt black has any compensation.}) (21... Qa6 22. g5 Bxd5 (22... Nxd5 23.
exd5 Bf5 24. Qd4 $18) (22... Nd7 23. Qd4 Ne5 24. f4 $18) 23. exd5 Nd7 24. Qd4
f6 25. Bh3 $18) (21... Ne8 {Perhaps black's best practical try, though I think
white has a very commanding position. One sample line follows.} 22. Qd4 (22. g5
) 22... f6 23. g5 Bf7 24. f4 e5 25. Qe3) 22. exd5 Qb6 {
Otherwise white plays g5 + Qd4.} 23. g5 Nd7 (23... Ne8 24. f4 Rc4 25. f5 $18) (
23... Nh5 24. Bd3 $18) 24. f4 {Preventing Ne5 and aiming for f5. Black is
paralysed and lost according to the following analysis.} Rc4 (24... Rb7 25. Bd3
a5 26. Qe2 $18 {Threat is Bxg6.}) (24... a5 25. Bh3 $18) (24... Rc7 25. Bh3 $18
) 25. Re1 {White threat is Bd3 + f5. The rook on e1 becomes handy in
variations where black plays Ne5, when Rxe5 is likely to be crushing.} Qb7 (
25... a6 26. Bd3 Qb7 (26... Qc7 27. f5 gxf5 28. Rf2 Ne5 29. Rxf5 $18) 27. f5
Ne5 (27... gxf5 28. Bxf5 Ne5 29. Rxe5 $18) 28. fxg6 fxg6 29. Bf1 e6 30. Bh3 Re8
31. Bxe6+ Rxe6 32. dxe6 Nf3 33. Qg2 Re4 34. Rxe4 Qxe4 35. Bc3 $18) (25... a5
26. bxa5 $18) 26. Rf2 {The situation may be more unclear after the
alternatives. This seems to win outright though. White renews the threat of f5,
now that black defended against Bd3 with Qb7.} (26. Rh3 Rbc8 27. Bxc4 Rxc4 28.
Rf1 f5) (26. Bxc4 bxc4 27. Qd4 f6 28. c3 a5 29. bxa5 Qb5) (26. Bd3 Qxd5) 26...
Qb6 (26... Nb6 27. f5 gxf5 28. Bxc4 Nxc4 29. Qd3 $18) (26... f6 {Desperate defe
nse. White can probably carry on the attack decisively in several ways.} 27.
Rg2 (27. Rh2) (27. Bd3) (27. Re3)) (26... a6 27. f5 gxf5 28. Bd3 Ne5 (28...
Qxd5 29. Rxf5 Qc6 30. Ref1 $18) 29. Bxf5 $18) (26... Rbc8 27. Bxc4 {
followed by f5.}) 27. Rf3 {Defending against Rxb4. What is black to do?} (27.
f5 Rxb4) 27... Qb7 (27... Rb7 28. f5 Ne5 (28... gxf5 29. Rxf5 Ne5 30. Bd3 $18)
29. fxg6 $18) (27... a6 28. f5 Ne5 (28... gxf5 29. Qd3 $18) 29. fxg6 $18) 28.
f5 Ne5 (28... gxf5 29. Rxf5 Ne5 30. Bd3 e6 31. dxe6 fxe6 32. Rf6 $18) 29. Rxe5
dxe5 30. fxg6 $18) 17. g5 b4 (17... Nd7 18. Bxh8 Kxh8 19. Qd4+ f6 20. Nd5 (20.
gxf6 $5 Nxf6 21. e5 dxe5 22. Qxe5 Qb6) 20... Bxd5 21. Qxd5 Rf8 22. f4 Qb6 23.
e5 fxe5 24. Bh3 b4 25. Bxd7 bxa3 26. b3 Rxf4 27. Rhf1 $18) (17... Nh5 18. Bxh8
Kxh8 19. Qd4+ f6 20. Rxh5 (20. gxf6 $5 Nxf6 21. e5 dxe5 22. Qxe5 Qb6) 20...
gxh5 21. gxf6 Qb6 22. Nxb5 Qxd4 23. Nxd4 Bd7 24. fxe7 Re8 25. Bd3 Rxe7 26. Rh1
Be8 {I think white is winning.}) 18. Nb5 Qa4 (18... Nh5 {
Not very attractive. One sample line follows.} 19. Bxh8 (19. Qxb4 $2 Qxb4 20.
axb4 Ng3) 19... Rxb5 (19... Kxh8 20. Qd4+ f6 21. Rxh5 gxh5 22. gxf6 Qb6 23.
fxe7+ Qxd4 24. Nxd4 {I think white is winning.}) 20. Bxb5 Qxb5 21. a4 (21. Qd4)
21... Qxa4 22. b3) (18... Ne8 19. Qxb4 Qxb4 20. axb4 $16) 19. Rh2 $1 {
The crucial move.} bxa3 {This ultimately leads to a lost position. The
alternatives are not much better though.} (19... b3 20. c4 Ne8 21. Nc3 Qa5 (
21... Qa6 22. Bxh8 Kxh8 23. Nd5 $40) (21... Qd7 22. Bxh8 Kxh8 23. Nd5 $40) 22.
Nd5 Qxd2 23. Nxe7+ Kf8 24. Rhxd2 Kxe7 25. Bxh8 Bxc4 26. Bg2 $16) (19... Ne8 20.
Qxb4 Qxb4 21. axb4 $16) 20. b3 Rxb5 (20... Bxb3 21. cxb3 Qxb3+ 22. Ka1 {
Black is unable to carry on the attack.} Ne8 (22... Nh5 23. Bxh8 Kxh8 24. Qd4+
Kg8 25. Rb1 Qxf3 26. Bc4 Qf4 27. Rxh5 Qe5 28. Bxf7+ Kxf7 29. Qxe5 dxe5 30. Rh3
$18) (22... a6 23. gxf6 axb5 24. fxe7 f6 25. Rb1 Qf7 26. Rxb5 $18) (22... Nd7
23. Bxh8 Kxh8 24. Qd4+ f6 (24... e5 25. Qxd6 $18) 25. Rb1 Qf7 (25... Qxf3 26.
Rf2 Qg3 27. gxf6 exf6 28. Rxf6 Qe5 29. Rxd6 Qxd4+ 30. Nxd4 $18) 26. Bh3 Rd8 27.
Bxd7 Rxd7 28. Nxa3 Rxb1+ 29. Nxb1 e5 30. Qc3 $18) 23. Bxh8 Kxh8 24. Rb1 Qa4 25.
Qd4+ Qxd4+ 26. Nxd4 Rxb1+ 27. Kxb1 Kg8 (27... f6 28. Ne6 $18) 28. Ka2 $18) (
20... Nxe4 21. fxe4 Rxb5 22. Bxb5 Qxb5 23. Bxh8 Kxh8 24. Qd4+ Qe5 25. Qxe5+
dxe5 26. Rhd2 $18) 21. Bxb5 Qxb5 22. gxf6 exf6 23. Bxa7 $1 $18 {After 9...
, the gravity of avoiding clearly inferior positions have led to this position.
However, here black is simply lost.} f5 24. Bd4 Be5 (24... f6 25. Ka2) 25. Bxe5
Qxe5 26. Qd4 f6 (26... fxe4 27. fxe4 f5 28. exf5 Bxf5 29. Re2 Qxd4 30. Rxd4 Rc3
31. Ka2) 27. Rhd2 fxe4 28. fxe4 g5 29. c4 Re8 30. Qxe5 dxe5 {
Hoshad reconnected.} 31. Rd8 Rxd8 32. Rxd8+ Kf7 33. Ka2 f5 34. exf5 Bxf5 35. c5
{Flying Saucers resigns  (Lag: Av=0.20s, max=0.7s)} 1-0

parisestmagique wrote on 08/29/06 at 16:16:43:


Interesting. Diagram after 16.. Bf8.

http://www.france-echecs.com/diagramme/imgboard.phpfen=1rr2bk1/p3pp1p/3pbnpP/qp6...

I assume 17 Nd5 is critical:

I) 17.. Qxd2 18 Nxf6+ exf6 19 Rxd2. Now Bxa7 follows, unless 19.. b4. It looks to me like white has a decisive endgame advantage, I can't make anything out of black's activity.

II) 17.. Qa4 18 b3! Qxa3 19 Bb2 Qc5 20 b4! Qc5 21 Rh2 and the bishop on f8 is dead. White threatens Qd4 + g5, and Bxd5 from black is no salvation. I think white is completely winning here. 

Anything to improve on black's play after 16.. Bf8?

The alternative 16.. b4 is the only other serious try for black I can find. Here's the position after 17 Nb5 Rxb5 18 Bxb5 Qxb5 19 hxg7 bxa3 20 Qd3.

http://www.france-echecs.com/diagramme/imgboard.phpfen=2r3k1/p3ppPp/3pbnp1/1q6/3...

After 20.. Qxd3, I can't decide whether Rxd3 or cxd3 is more promising for White. Can black hold this position?

Below is a game I played as black in the 3rd PAL/CSS Freestyle Tournament. It looks to me like white found a huge improvement on a line that was already considered somewhat critical for black according to what I've been able to dig up here. 

The line in question is the Kb1, g4, h4-h5-h6 method. 

In the bottom, I give game as PGN with time usage noted, and a few alternative moves added in for reference in discussion. 

Here are the main points according to my analysis:

17 g5! is the new move as far as I know, where otherwise 17 Nd5 was given as leading to some endgame advantage for white. 

The critical move to make this work is 19 Rh2! After this, I think black is just lost. Please note also 23 Bxa7! In this position, the point is that black's dark bishop is effectively dead, white just plays Bd4 to liquidate any black activity, and white will have a simple won ending. Some notes on alternatives:

20.. Bxb3 does not give black enough compensation according to my analysis. White can free his game quite easily.

Hence, 19.. b3 is necessary, but I think black can do no better than reaching very bad endings. White always has f3-f4-f5 as an eventual option to settle the issue. 

17.. Nd7 looks no fun for me either. Then, it looks like black must either play h5 at move 13 or 14 (which should be bad, no?), or try 16.. b4. After 16.. b4 17 Nb5! (after 17 Nd5, black can comfortably hit with both bishop and knight), an ending is reached with white being the exchange up. What does the dragon experts say here, do you think black has enough structural compensation?

My conclusion would be that the g4 + h4-h5-h6 plan just looks crushing. Is this well-known stuff? Can black be saved?
  

[Event "3rd PAL/CSS Freestyle Tournament - Prel"]
[Site "playchess.com #069217"]
[Date "2006.06.17"]
[Round "5"]
[White "Hoshad"]
[Black "Flying Saucers"]
[Result "1-0"]
[ECO "B76"]
[WhiteElo "2245"]
[BlackElo "2401"]
[Annotator "Klump,Rasmus"]
[PlyCount "69"]
[EventDate "2006.06.17"]
[EventType "swiss (rapid)"]

1. Nc3 {123} c5 {224} 2. e4 {138} d6 {30} 3. Nf3 {46} Nf6 {20} 4. d4 {88} cxd4
{9} 5. Nxd4 {15} g6 {5} 6. Be3 {58} Bg7 {17} 7. f3 {65} O-O {4} 8. Qd2 {77} Nc6
{9} 9. O-O-O {65} Nxd4 {429} 10. Bxd4 {64} Be6 {3} 11. Kb1 {190} Qc7 {14} 12.
g4 {96} Rfc8 {23} 13. h4 {38} Qa5 {12} (13... h5) 14. a3 {81} Rab8 {488} (14...
h5) 15. h5 {201} b5 {81} 16. h6 {123} Bh8 {106} (16... b4 17. Nb5 Rxb5 18. Bxb5
Qxb5 19. hxg7 bxa3 20. Qd3) 17. g5 {420} b4 {166} (17... Nd7 18. Bxh8 Kxh8 19.
Qd4+ f6 20. Nd5) 18. Nb5 {109} Qa4 {37} 19. Rh2 {256} bxa3 {98} (19... b3 20.
c4 Ne8 21. Nc3) 20. b3 {18} Rxb5 {103} (20... Bxb3 21. cxb3 Qxb3+ 22. Ka1) 21.
Bxb5 {32} Qxb5 {3} 22. gxf6 {23} exf6 {40} 23. Bxa7 {469} f5 {1110} 24. Bd4 {52
} Be5 {185} 25. Bxe5 {69} Qxe5 {11} 26. Qd4 {54} f6 {31} 27. Rhd2 {303} fxe4 {
135} 28. fxe4 {112} g5 {28} 29. c4 {121} Re8 {9} 30. Qxe5 {97} dxe5 {
Hoshad reconnected. 21} 31. Rd8 {37} Rxd8 {46} 32. Rxd8+ {14} Kf7 {4} 33. Ka2 {
20} f5 {98} 34. exf5 {18} Bxf5 {13} 35. c5 {
Flying Saucers resigns  (Lag: Av=0.20s, max=0.7s) 19} 1-0