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Black to move.........f5 forced win or draw?

Posted: Mon May 30, 2011 4:38 am
by AnthonyTheSage
r2q1rk1/5pp1/p1n1p1p1/1p1p4/3Pn1Pb/P1P1BN1P/1P2NP2/R2QR1K1 b - - 0 17

I came across this position in a 5min blitz game this morning. I played f5. Most engines like Na5 here. The only engines I could find that liked f5 were deep junior 11.1a and everybodys fav spark 0.4. With a quick analysis I still like f5, puts white under extreme pressure. I'm still not convinced that white can escape with his scalp. I'm using a single core 1.6 laptop, so the performance is probably way behind you guys. Take a look and let me know what you guys come up with on your monster hardware. Also I'm looking for some good attacking engines to supplement my analysis in situations like this. Any suggestions would be great. Thanks.

Re: Black to move.........f5 forced win or draw?

Posted: Tue May 31, 2011 10:17 pm
by ernest
Houdini at depth 28 (more than 2 hours on my Core 2 Duo @3GHz):

r2q1rk1/5pp1/p1n1p1p1/1p1p4/3Pn1Pb/P1P1BN1P/1P2NP2/R2QR1K1 b - - 0 1
Analysis by Houdini 1.5a w32 gtb:
1. =/+ (-0.28): 1...f5 2.Nf4 Nxf2 3.Qe2 Ne4 4.Nxe6 Qd6 5.Nxh4 Qxe6 6.gxf5 gxf5 7.Bf4 Rf7 8.Nf3 Qe8 9.Ng5 Re7 10.Qg2 Na5 11.Nxe4 fxe4 12.Rf1 Qd7 13.Bh2 Nc4 14.Rae1 Rf7 15.Rxf7 Qxf7 16.b3
2. =/+ (-0.27): 1...Na5 2.Nf4 Nc4 3.Nd3 a5 4.a4 b4 5.cxb4 axb4 6.Qe2 b3 7.Rec1 Bf6 8.Kg2 Qe8 9.Nde5 Ned6 10.Qd3 Nxb2 11.Qxb3 Nbc4 12.Nxc4 Nxc4 13.Bf4 Qd7 14.Rcb1 Qd8

Re: Black to move.........f5 forced win or draw?

Posted: Wed Jun 01, 2011 1:25 pm
by zullil
Stockfish-2.1.1 (8 threads) suggests Nf4 in reply to f5, leaving Black with an advantage of less than half a pawn:

Code: Select all

Searching: r2q1rk1/6p1/p1n1p1p1/1p1p1p2/3Pn1Pb/P1P1BN1P/1P2NP2/R2QR1K1/ w - -
infinite: 1 ponder: 0 time: 0 increment: 0 moves to go: 0
 1   -0.24   00:01     683  Nf4 
 2   +0.48   00:01    1705  Nf4 Kf7 
 3   +0.36   00:01    2097  Nf4 Kf7 gxf5 gxf5 
 4   +0.36   00:01   10646  Nf4 Kf7 gxf5 gxf5 
 5   +0.20   00:01   13548  Nf4 Kf7 gxf5 gxf5 Qc2 
 6   +0.28   00:01   18087  Nf4 Kf7 Nd3 Kg8 Nde5 Nxe5 Nxe5 
 7   +0.28   00:01   45939  Nf4 Kf7 a4 Qf6 axb5 axb5 gxf5 gxf5 
 8   +0.32   00:01   65428  Nf4 Kf7 a4 Qf6 gxf5 gxf5 Ng2 g5 Nxh4 gxh4 axb5 axb5 
 9   +0.28   00:01  133278  Nf4 Kf7 a4 Qf6 gxf5 gxf5 axb5 axb5 Rxa8 Rxa8 Ng2 g5 
                            Nxh4 gxh4 Qh5+ Qg6 Qxg6+ Kxg6 Nxh4+ Kf7 
10   +0.32   00:01  233167  Nf4 Nxf2 Bxf2 Bxf2+ Kxf2 fxg4 hxg4 Rxf4 Rxe6 Rf6 
                            Rxf6 gxf6 Qd3 
11   +0.32   00:01  247244  Nf4 Nxf2 Bxf2 Bxf2+ Kxf2 fxg4 hxg4 Rxf4 Rxe6 Rf6 
                            Rxf6 gxf6 Qd3 
12   -0.20   00:01  382161  Nf4 Nxf2 Bxf2 Bxf2+ Kxf2 fxg4 Qe2 Rxf4 Qxe6+ Kh8 
                            hxg4 Qh4+ Ke3 Rxf3+ Kxf3 Rf8+ Kg2 
13   -0.16   00:01  669147  Nf4 Nxf2 Bxf2 Bxf2+ Kxf2 fxg4 Qe2 e5 Nxe5 Rxf4+ Kg1 
                            Nxe5 Qxe5 Rf6 hxg4 Qd7 Qg3 Rf8 Rf1 Qf7 Qg2 Qe6 Rxf6 
                            gxf6 
14   -0.16   00:01  861161  Nf4 Nxf2 Bxf2 Bxf2+ Kxf2 fxg4 Qe2 e5 Nxe5 Rxf4+ Kg1 
                            Nxe5 Qxe5 Rf6 hxg4 Qd7 Qg3 Rf8 Rf1 Qf7 Qg2 Qe6 Rxf6 
                            gxf6 
15   -0.16   00:01  984484  Nf4 Nxf2 Bxf2 Bxf2+ Kxf2 fxg4 Qe2 e5 Nxe5 Rxf4+ Kg1 
                            Nxe5 Qxe5 Rf6 hxg4 Qd7 Qg3 Rf8 Rf1 Qf7 Qg2 Qe6 Rxf6 
                            gxf6 
16   -0.16   00:01   1222K  Nf4 Nxf2 Bxf2 Bxf2+ Kxf2 fxg4 Qe2 e5 Nxe5 Rxf4+ Kg1 
                            Nxe5 Qxe5 Rf6 hxg4 Qd7 Qg3 Rf8 Rf1 Qf7 Qg2 Qe6 Rxf6 
                            gxf6 
17   -0.04   00:02   4220K  Nf4 Nxf2 Bxf2 Bxf2+ Kxf2 fxg4 Qe2 e5 Nxe5 Rxf4+ Kg1 
                            Nxe5 Qxe5 Rf6 hxg4 Qd7 Qg3 Rf8 Rf1 Qf7 Qg2 Qe6 Rxf6 
                            gxf6 Kf2 f5 
18   +0.00   00:02   5796K  Nf4 Nxf2 Bxf2 Bxf2+ Kxf2 fxg4 Qe2 e5 Nxe5 Rxf4+ Kg1 
                            Nxe5 Qxe5 Rf7 hxg4 Qh4 Qxd5 Rf8 Rf1 Qg3+ Kh1 Qh3+ 
                            Kg1 Qg3+ 
19   -0.16   00:02   8156K  Nf4 Nxf2 Bxf2 Bxf2+ Kxf2 fxg4 Qe2 Rxf4 Qxe6+ Kf8 
                            hxg4 Qh4+ Ke3 Qxg4 Qxg4 Rxg4 Kf2 Re8 a4 b4 Rg1 Rxg1 
                            Rxg1 Re6 cxb4 Nxb4 
20   -0.08   00:03  10519K  Nf4 Nxf2 Bxf2 Bxf2+ Kxf2 fxg4 Qe2 Rxf4 Qxe6+ Kf8 
                            hxg4 Qh4+ Ke3 Qxg4 Qxg4 Rxg4 Kf2 Re8 Rg1 Rxg1 Rxg1 
                            Re6 Rg5 Rd6 Ne5 Nxe5 dxe5 Re6 Ke3 Kf7 
21   +0.00   00:04  14917K  Nf4 Nxf2 Bxf2 Bxf2+ Kxf2 fxg4 Qe2 Rxf4 Qxe6+ Kf8 
                            hxg4 Qh4+ Ke3 Qxg4 Qxg4 Rxg4 Kf2 Re8 Rg1 Rxg1 Rxg1 
                            Kf7 Ng5+ Kg8 Nf3 Kf7 
22   +0.00   00:05  21407K  Nf4 Nxf2 Bxf2 Bxf2+ Kxf2 fxg4 Qe2 Rxf4 Qxe6+ Kf8 
                            hxg4 Qh4+ Ke3 Qxg4 Qxg4 Rxg4 Kf2 Re8 Rg1 Rxg1 Rxg1 
                            Kf7 Ng5+ Kg8 Nf3 Kf7 
23   +0.00   00:07  34390K  Nf4 Nxf2 Bxf2 Bxf2+ Kxf2 fxg4 Qe2 Rxf4 Qxe6+ Kf8 
                            hxg4 Qh4+ Ke3 Qxg4 Qxg4 Rxg4 Kf2 Re8 Rg1 Rxg1 Rxg1 
                            Kf7 Ng5+ Kg8 Nf3 Kf7 
24   +0.00   00:10  59757K  Nf4 Nxf2 Bxf2 Bxf2+ Kxf2 fxg4 Qe2 Rxf4 Qxe6+ Kf8 
                            hxg4 Qh4+ Ke3 Qxg4 Qxg4 Rxg4 Kf2 Re8 Rg1 Rxg1 Rxg1 
                            Kf7 Ng5+ Kg8 Nf3 Kf7 
25   -0.28   00:26 169578K  Nf4 Nxf2 Bxf2 Bxf2+ Kxf2 fxg4 Qe2 e5 Nxe5 Rxf4+ Kg3 
                            Re4 Qd3 Nxe5 dxe5 gxh3 Kh2 Rf4 Rf1 g5 Rxf4 gxf4 Rf1 
                            Qd7 Qxh3 Qe7 Rxf4 Qxe5 Qf5 Qxf5 Rxf5 
26   -0.48   00:36 242353K  Nf4 Nxf2 Qe2 Ne4 Nxe6 Qd6 Nxh4 Qxe6 gxf5 gxf5 Bf4 
                            Qf6 Nf3 Nd8 a4 b4 cxb4 Nc6 Rad1 Nxb4 Rc1 Rac8 Red1 
                            g5 Rxc8 Rxc8 Be5 
27   -0.40   00:45 305492K  Nf4 Nxf2 Qe2 Ne4 Nxe6 Qd6 Nxh4 Qxe6 gxf5 gxf5 Bf4 
                            Qf6 Nf3 Nd8 a4 b4 cxb4 Nc6 Rad1 Nxb4 Qg2 Rac8 Re2 
                            Nc6 Rc2 Ne7 Rxc8 Rxc8 Be5 Qh6 h4 Qe3+ Kh1 
28   -0.40   01:03 440487K  Nf4 Nxf2 Qe2 Ne4 Nxg6 Bxe1 Nxf8 Qxf8 Rxe1 Re8 Nd2 
                            e5 Nxe4 fxe4 Rf1 Qd6 Qh2 Rf8 Rxf8+ Kxf8 Qf2+ Ke8 
                            dxe5 Nxe5 Qf5 Nf3+ Kf1 Qc6 Qh7 Kf7 Ke2 Qe6 Qf5+ 
                            Qxf5 gxf5 Kf6 
29   -0.24   01:46 754262K  Nf4 Nxf2 Qe2 Ne4 Nxe6 Qd6 Nxh4 Qxe6 gxf5 gxf5 Bf4 
                            Qf6 Nf3 Ne7 h4 Ng6 Bg5 Qd6 Qh2 Qxh2+ Kxh2 Kf7 Kg2 
                            Rh8 a4 bxa4 Rxa4 Kg8 Ra1 Rb8 Rb4 Rxb4 
30   -0.32   02:55   1282M  Nf4 Nxf2 Qe2 Ne4 Nxg6 Bxe1 Nxf8 Qxf8 Rxe1 Re8 Nd2 
                            e5 Nxe4 fxe4 Rf1 Qd6 Qh2 Rf8 Rxf8+ Kxf8 Qf2+ Ke8 
                            Kg2 Qf8 h4 a5 Qxf8+ Kxf8 Kf2 Ke8 Ke2 Kf7 Bf2 a4 h5 
                            exd4 
31   -0.40   04:15   1898M  Nf4 Nxf2 Qe2 Ne4 Nxg6 Bxe1 Nxf8 Qxf8 Rxe1 Re8 Nd2 
                            e5 Nxe4 fxe4 Rf1 Qd6 Qf2 Rf8 Qxf8+ Qxf8 Rxf8+ Kxf8 
                            dxe5 Nxe5 b3 Ke7 Kf2 Nf3 
32   -0.40   05:44   2596M  Nf4 Nxf2 Qe2 Ne4 Nxg6 Bxe1 Nxf8 Qxf8 Rxe1 Re8 Nd2 
                            e5 Nxe4 fxe4 Rf1 Qd6 Qf2 Rf8 Qxf8+ Qxf8 Rxf8+ Kxf8 
                            dxe5 Nxe5 b3 Ke7 Kf2 Nf3 
33   -0.40   13:11   6124M  Nf4 Nxf2 Qe2 Ne4 Nxe6 Qd6 Nxh4 Qxe6 gxf5 gxf5 Bf4 
                            Ra7 Nf3 Qg6+ Qg2 Qh5 Kh2 Nd8 Be5 Ne6 a4 b4 cxb4 g5 
                            Kg1 Rh7 Rac1 Qxh3 Rc6 Re8 Rxa6 g4 Qxh3 Rxh3 Nh2 Rb3 
                            b5 Kf7 Ra7+ Kg6 Re2 
34   -0.44   17:01   7923M  Nf4 Nxf2 Qe2 Ne4 Nxe6 Qd6 Nxh4 Qxe6 gxf5 gxf5 Bf4 
                            Ra7 Nf3 Qg6+ Qg2 Qh5 Kh2 Nd8 Be5 Ne6 a4 b4 cxb4 g5 
                            Kg1 Rh7 Rac1 Qxh3 Rc6 Re8 Rxa6 g4 Qxh3 Rxh3 Nh2 Rb3 
                            b5 Kf7 Ra7+ Re7 Rxe7+ 
35   -0.57   28:32  13441M  Nf4 Nxf2 Qe2 Ne4 Nxe6 Qd6 Nxh4 Qxe6 gxf5 gxf5 Bf4 
                            Ra7 Nf3 Qg6+ Qg2 Qh5 Kh2 Nd8 Ng5 Rf6 Qf3 Qh4 Rg1 
                            Nf7 Nxe4 fxe4 Qg4 Qf2+ Kh1 Qf3+ Qxf3 exf3 Be5 Nxe5 
                            dxe5 Rf5 Raf1 
36   -0.44   38:39  18309M  Nf4 Nxf2 Qc2 Ne4 Nxe6 Qd6 Nxf8 Bxe1 Rxe1 Rxf8 Qg2 
                            Na5 gxf5 gxf5 Bc1 Nc4 Ng5 Re8 h4 
37   -0.32 1:03:46  30627M  Nf4 Nxf2 Qc2 Ne4 Nxe6 Qd6 Nxf8 Bxe1 Rxe1 Rxf8 Qg2 
                            Na5 Bc1 Nc4 Ng5 a5 Rf1 Qe7 h4 a4 gxf5 gxf5 
38   -0.40 1:46:35  51551M  Nf4 Nxf2 Qe2 Ne4 Nxe6 Qd6 Nxf8 Bxe1 Rxe1 Rxf8 Qg2 
                            Na5 Bc1 Nc4 Ng5 Qf6 gxf5 gxf5 Rf1 Qg6 h4 Re8 Qf3 
                            Ncd6 Kh2 Rc8 Kg1 Rf8 Qg2 Rf6 Nh3 Qf7 Nf4 
39   -0.48 2:53:51  84806M  Nf4 Nxf2 Qe2 Ne4 Nxe6 Qd6 Nxf8 Bxe1 Rxe1 Rxf8 Qg2 
                            a5 Kh1 Nd8 gxf5 gxf5 Rg1 Ne6 Bd2 Rf6 h4 Qc7 Ne5 b4 
                            axb4 axb4 Ra1 Qb7 Be1 bxc3 bxc3 Nf8 Qa2 Rb6 Kg1 Rb2 
                            Qa7 Ne6 Kf1 
40   -0.36 3:02:08  88899M  Nf4 Nxf2 Qe2 Ne4 Nxe6 Qd6 Nxf8 Bxe1 Rxe1 Rxf8 Qg2 
                            a5 Kh1 Nd8 gxf5 gxf5 Rg1 Ne6 Bd2 Rf6 h4 Qc7 Ne5 b4 
                            axb4 axb4 Ra1 Qb7 Be1 bxc3 bxc3 Nf8 Qa2 Rb6 Kg1 Rb2 
                            Qa7 Ne6 Kf1 
Nodes: 88899060632
Nodes/second: 8134655
Best move: Nf4
Ponder move: Nxf2

Re: Black to move.........f5 forced win or draw?

Posted: Fri Jun 03, 2011 6:29 am
by AnthonyTheSage
[Event "?"]
[Site "?"]
[Date "2011.06.02"]
[Round "?"]
[White "f5 Position"]
[Black "?"]
[Result "*"]
[Annotator "Dr.Dynamic2011"]
[SetUp "1"]
[FEN "r2q1rk1/5pp1/p1n1p1p1/1p1p4/3Pn1Pb/P1P1BN1P/1P2NP2/R2QR1K1 b - - 0 1"]
[PlyCount "20"]

1... f5 2. Nf4 Nxf2 3. Qe2 Ne4 4. Nxh4 (4. Nxe6 Qd6 5. Nxf8 Bxe1 6. Nxg6 fxg4
7. Nxe1 Qg3+ 8. Kh1 Qxh3+ 9. Kg1 Re8 {Deep Junior 11.1a Drawish}) 4... Qxh4 5.
Nxg6 Qxh3 6. Nxf8 (6. a4 b4 7. Nxf8 Rxf8 8. Qg2 Qxg2+ 9. Kxg2 f4 10. Bc1 g5 11.
Rh1 Na5 12. Rb1 {Houdini 1.5a Similar to Fritz variation with a4 thrown in,
another big advantage for Black(-.90).}) 6... Rxf8 7. Qg2 Qxg2+ 8. Kxg2 f4 9.
Bc1 f3+ 10. Kf1 Kh7 11. Rd1 {Fritz 12 Huge advantage to black(-1.20).} *


This is just shallow analysis, about 5 seconds per move. Deep Junior 11.1a goes right for the king and it leads to a drawish position. Fritz 12 and Houdini both have have to same idea with the passed f pawn. either way f5 leads to a tough position for white. With accurate play maybe a draw...........