Very difficult Test position: 1.Qf4!!

[jarechu]

Is any engine able to find this:

[D]r4r1k/ppq4p/2n1bppP/2P1p3/2B2n2/1N3Q2/PBP2PP1/3RR1K1 w - -

[Event "Active"]
[Site "Barcelona (Spain)"]
[Round ""]
[White "Rahal Michael (ENG)"]
[Black "Cuartas Jaime Alexander (COL)"]
[Result ""]
[Eco ""]
[Annotator ""]
[Source ""]
[SetUp "1"]
[FEN "r4r1k/ppq4p/2n1bppP/2P1p3/2B2n2/1N3Q2/PBP2PP1/3RR1K1 w - - 0 1"]

1.Qxf4 exf4 2.Rxe6 Ne5 3.Rxe5 fxe5 4.Rd7 Qb8 5.Nd4 Qe8 6.Nf3
Rf5 7.Rd5 Rd8 8.Rxe5 Rxe5 9.Bxe5+ Qxe5 10.Nxe5 *

[S.Taylor]

Very difficult? Maybe. But you can see the smoke there. It invites looking into if you reach this position in a tournament game.
It's a little more difficult to convince yourself that it will work all the way, and to be absolutely clear about it before giving up the queen. But a normal player should certainly see the first few moves and get deeply engrossed in it.

[BBauer]

Since this is a cc forum the original poster meant

*very difficult for computers*

At least glaurung didn't find 1. Qf4 whithin 5 sec.
kind regards
Bernhard

[hgm]

How do you know the move is any good?

[Marek Soszynski]

[D]r4r1k/ppq4p/2n1bppP/2P1p3/2B2n2/1N3Q2/PBP2PP1/3RR1K1 w - - 0 1

Analysis by Zappa Mexico II:

1.Bxe6 Nxe6 2.Rd6 Qf7 3.Red1 Rae8 4.c4 Nf4 5.Bc1 Ne6 6.Bb2
=/+ (-0.47) Depth: 7/24 00:00:01 157kN
= (0.00) Depth: 18/53 00:06:15 261mN
1.Qxf4 exf4 2.Rxe6 Ne5 3.Rxe5 b5 4.Be6 Rae8 5.Rd7 Qc8 6.Rd6 Qc7 7.Re4 Rd8 8.Rxd8 Qxd8 9.Bd4 Qc7 10.Bd5 Qd7
+- (2.62) Depth: 18/55 00:18:01 725mN
+- (2.62) Depth: 19/55 00:22:49 914mN

(Soszynski, 29.05.2008)

[Eelco de Groot]

How do you know the move is any good?

I think it is somewhere on the edge of findability. A longe forced variation, if only we had a better means of weeding out the nonsensical stuff. In the words of Larry about Knight versus Bad Bishop: "I feel we are missing something here." The move 1.Qxf4 will be played if the score were to rise above -0.80 which is the evaluation for 1.Bxe6 up to about plydepth 15, but after 1.Qxf4 exf4 you still need about 18 plies to get -0.80 and twenty plies to see a really good score.

But the point is, many of the moves make no sense at all and fall to -8 Surely there must be a way to exploit this!

CPU0: AuthenticAMD x86 Family 15 Model 31 Stepping 0 2009 MHz
GUI: Tablebases with 0 pieces found! [Cache: 4 MB + internal 0.00 MB]
GUI: Shredderbases with 0 pieces found (0 MB)
Engine: Ancalagon 2.0 Beta 002 Build 18 29-05-2008 13:29h4 (256 MB)
by Tord Romstad, Eelco de Groot

After 1.Qxf4 exf4

[D]r4r1k/ppq4p/2n1bppP/2P5/2B2p2/1N6/PBP2PP1/3RR1K1 w - -

17 2:29 -0.98 2.Rxe6 Ne5 3.Rxe5 fxe5 4.Rd7 Qb8 5.Na5 Qe8 6.Nxb7 Rf6 7.Rg7 Qb8 8.c6 Qc8 9.Rg8+ Qxg8 10.Bxg8 Kxg8 11.Na5 Re8 12.Kh2 (83.714.828) 560
17 2:29 -3.62 2.Bxe6 Rad8 3.Rxd8 Qxd8 4.Bc4 Qd7 5.Nd2 Nd4 6.Re4 Nf5 7.Re6 Qd8 8.Ne4 Qd1+ 9.Bf1 Qxc2 10.Bxf6+ Kg8 11.a3 Nxh6 (83.714.828) 560
17 2:29 -8.07 2.Bf1 Rad8 3.Rxd8 Nxd8 4.Ba3 Kg8 5.c6 Qxc6 6.Bxf8 Kxf8 7.Nd4 Qd5 8.Nxe6+ Nxe6 9.a3 Ke7 10.Bd3 Qa2 11.Be4 Qb2 (83.714.828) 560

___________________________________________________________

18 6:09 -0.82 2.Rxe6 Ne5 3.Rxe5 fxe5 4.Rd7 Qb8 5.Na5 Qe8 6.Nxb7 Rf6 7.Rg7 Qb8 8.c6 a5 9.Bd5 Rf5 10.Ba3 Qa7 11.Rd7 (209.304.578) 567
18 6:09 -3.33 2.Bxe6 Rae8 3.Bc3 Rd8 4.Rxd8 Qxd8 5.Bc4 f3 6.Nd2 Nd4 7.Re4 Ne2+ 8.Bxe2 fxe2 9.Rxe2 Kg8 10.Ne4 Qd5 11.Re1 Qf5 12.Kf1 Qf4 (209.304.578) 567
18 6:09 -8.11 2.Bf1 Rad8 3.Rxd8 Nxd8 4.Ba3 Kg8 5.c6 Qxc6 6.Bxf8 Kxf8 7.Rd1 Ke7 8.Nd4 Qc5 9.Nxe6 Nxe6 10.Bd3 Qd5 11.c4 Qe5 12.Bc2 (209.304.578) 567

___________________________________________________________

19 13:20 +0.50 2.Rxe6 Ne5 3.Rxe5 fxe5 4.Rd7 Qb8 5.Na5 Qe8 6.Nxb7 Rf6 7.Rd5 Qa4 8.Bxe5 Qxc4 9.Bxf6+ Kg8 10.Rd7 Qe6 11.Rg7+ Kf8 12.Be7+ Qxe7 13.Rxe7 Kxe7 14.Nd6 (451.802.924) 564
19 13:20 -3.07 2.Bxe6 Rae8 3.Bc3 Ne5 4.Bxe5 fxe5 5.Rd7 Qc6 6.Rd6 Qa4 7.Bd7 Qb4 8.c3 Qxc3 9.Rc1 Qb4 10.Bxe8 Rxe8 11.Rd7 e4 12.Nd4 (451.802.924) 564
19 13:20 -8.23 2.Bf1 Rad8 3.Rxd8 Nxd8 4.Ba3 Qc6 5.Bb4 Kg8 6.Nd4 Qd5 7.Nxe6 Nxe6 8.c6 Rf7 9.cxb7 Rxb7 10.c4 Qh5 11.Bd6 Kf7 12.Be2 Qxh6 (451.802.924) 564

___________________________________________________________

20 31:20 +1.66 2.Rxe6 Ne5 3.Rxe5 fxe5 4.Rd7 Qb8 5.Na5 Rf5 6.Nxb7 Qf8 7.Nd6 Rb8 8.Bb3 Re8 9.c6 f3 10.Nxe8 Qxe8 11.gxf3 Qb8 12.Re7 Rg5+ 13.Kh2 (1.057.838.257) 562
20 31:20 -2.98 2.Bxe6 Rae8 3.Nd4 Nxd4 4.Bxd4 f3 5.Bd5 Rxe1+ 6.Rxe1 Qf4 7.c3 fxg2 8.Bxb7 Qxh6 9.Bxg2 Qg5 10.Re6 Kg8 11.Be3 Qg4 12.Re4 Qd1+ 13.Kh2 Qd5 14.Re7 Qxa2 (1.057.838.257) 562
20 31:20 -8.37 2.Bf1 Rad8 3.Rxd8 Nxd8 4.Ba3 Qc6 5.Bb4 Kg8 6.Nd4 Qd5 7.c6 Rf7 8.cxb7 Rxb7 9.Nxe6 Nxe6 10.a3 Kf7 11.c4 Qg5 12.Re4 Rb8 13.Bd6 (1.057.838.257) 562

___________________________________________________________

21 69:56 +1.74 2.Rxe6 Ne5 3.Rxe5 fxe5 4.Rd7 Qb8
5.Na5 Rf5 6.Nxb7 Qf8 7.Nd6 Rb8 8.Bb3 Re8
9.c6 a5 10.Bd5 a4 11.Nxe8 Qxe8
12.Ba3 Rh5 13.Re7 (2.315.381.277) 551

21 69:56 -2.98 2.Bxe6 Rad8 3.Rxd8 Qxd8 4.Bc4 f3
5.g3 Ne7 6.Ba3 a5 7.c6 Nxc6 8.Bxf8 Qxf8
9.Bd5 Ne5 10.Nd2 Qd6 11.c4 Qb4
12.Rd1 Qa4 13.Ra1 (2.315.381.277) 551

21 69:56 -8.49 2.Bf1 Rad8 3.Rxd8 Nxd8 4.Ba3 Kg8
5.c6 Qxc6 6.Bxf8 Kxf8 7.Nd4 Qd5
8.Nxe6+ Nxe6 9.c4 Qd7 10.Rb1 b6
11.Rb3 Nd4 12.Ra3 Kf7 13.Bd3 Ke6 (2.315.381.277) 551


Eelco

[Marc MP]

I let Chess Tiger 2007.1 - Gambit ponder on Qxf4 for a while. Here are the results:

Code: Select all

<snip>

00&#58;00&#58;29.6  1.   Score&#58; -2,28   depth&#58; 24 Qxf4 exf4 Rxe6 Ne5 Rxe5 fxe5 Rd7 Qb8 Bf7 Rxf7 Rxf7 Qe8 Rxb7 Rd8 Rxa7 Rd1+ Kh2 f3 gxf3 Qc6 Bxe5+ Kg8 Rg7+ Kf8 Bd6+ Ke8 

 00&#58;00&#58;57.7  1.   Score&#58; -2,02   depth&#58; 25 Qxf4 exf4 Rxe6 Ne5 Rxe5 fxe5 Rd7 Qb8 Bf7 Rxf7 Rxf7 Qe8 Rxb7 Rd8 Rxa7 Rd1+ Kh2 f3 gxf3 Rb1 Bc3 Qc6 Bxe5+ Kg8 Rg7+ Kf8 Bd6+ Ke8 

00&#58;04&#58;38.7  1.   Score&#58; -1,12   depth&#58; 25 Qxf4 exf4 Rxe6 Ne5 Rxe5 fxe5 Rd7 Qb8 Nd2 Qe8 Nf3 Rf5 Nxe5 Rxe5 Rd5 

00&#58;08&#58;44.8  1.   Score&#58; -0,62   depth&#58; 26 Qxf4 exf4 Rxe6 Ne5 Rxe5 fxe5 Rd7 Qb8 Nd2 Rf5 Nf3 b5 Nxe5 Qxe5 Bxe5+ Rxe5 Bxb5 Rxc5 c4 Re5 Bc6 Re1+ Kh2 

00&#58;20&#58;52.2  1.   Score&#58; 0,28   depth&#58; 26 Qxf4 exf4 Rxe6 Ne5 Rxe5 fxe5 Rd7 Qb8 Nd2 Rf5 Nf3 b5 Bd5 Qe8 Nxe5 Rxe5 c6 

00&#58;34&#58;35.6  1.   Score&#58; 1,67   depth&#58; 27 Qxf4 exf4 Rxe6 Ne5 Rxe5 fxe5 Rd7 Qb8 Nd2 Rf5 Nf3 b6 Bd5 bxc5 Bxa8 Kg8 Bd5+ Kf8 

01&#58;01&#58;07.2  1.   Score&#58; 2,16   depth&#58; 28 Qxf4 exf4 Rxe6 Ne5 Rxe5 b5 Be6 Rae8 Rd7 Qc8 Rxh7+ Kxh7 Bxc8 fxe5 Bd7 e4 Bg7 a6 Bxf8 Rxf8 c6 e3 Bg4 Rc8 

[jarechu]

Very difficult? Maybe. But you can see the smoke there. It invites looking into if you reach this position in a tournament game.
It's a little more difficult to convince yourself that it will work all the way, and to be absolutely clear about it before giving up the queen. But a normal player should certainly see the first few moves and get deeply engrossed in it.

The game was a rapid one and 1.Qf4!! and 5.Nd4!! was played, but white on time presure finally lost this because he couldn't find 7.Rd5.

Very good for zappa and Tiger. Maybe engines should give a plus when a royal pawn (h6) is present in the castle. Also look at those bishops. I really don't know how difficult will be to do that and, of course, if it works in "normal" chess positions.

[jarechu]

The game was a rapid one and 1.Qf4!! and 5.Nd4!! was played, but white on time presure finally lost this because he couldn't find 7.Rd5.

Just correcting myself. Rahal played 7. Rd5 but after 7... Rd8 he played 8.Rd8? instead 8.Re5!.

[Dann Corbit]

Is any engine able to find this:

[D]r4r1k/ppq4p/2n1bppP/2P1p3/2B2n2/1N3Q2/PBP2PP1/3RR1K1 w - -

[Event "Active"]
[Site "Barcelona (Spain)"]
[Round ""]
[White "Rahal Michael (ENG)"]
[Black "Cuartas Jaime Alexander (COL)"]
[Result ""]
[Eco ""]
[Annotator ""]
[Source ""]
[SetUp "1"]
[FEN "r4r1k/ppq4p/2n1bppP/2P1p3/2B2n2/1N3Q2/PBP2PP1/3RR1K1 w - - 0 1"]

1.Qxf4 exf4 2.Rxe6 Ne5 3.Rxe5 fxe5 4.Rd7 Qb8 5.Nd4 Qe8 6.Nf3
Rf5 7.Rd5 Rd8 8.Rxe5 Rxe5 9.Bxe5+ Qxe5 10.Nxe5 *

Rybka had a terrible time of it:

Code: Select all

1) Qxf4; pv Qxf4 exf4 R 
    Searching move: Qf3xf4, Qf3xf4
    Best move (Rybkav2.3.2a.w32): Bc4xe6
    Not found in: 5:00:00
      5	00:00	       3.250	104.000	+0.35	Bc4xe6 Nf4xe6 Rd1d6
      6	00:01	       6.494	105.553	+0.38	Bc4xe6 Nf4xe6 Rd1d6 Qc7e7
      7	00:01	      11.539	93.777	+0.37	Bc4xe6 Nf4xe6 Rd1d6 Qc7e7 Qf3d5
      8	00:01	      31.794	98.957	+0.44	Bc4xe6 Nf4xe6 Rd1d6 Qc7f7 Qf3g4 Ra8e8
      9	00:01	      68.895	95.984	+0.36	Bc4xe6 Nf4xe6 Rd1d6 Qc7f7 a2a4 Ra8d8 a4a5
     10	00:02	     118.193	95.524	+0.44	Bc4xe6 Nf4xe6 Rd1d6 Qc7f7 a2a4 Ne6f4 g2g3 Nf4e6
     11	00:03	     195.124	96.852	+0.40	Bc4xe6 Nf4xe6 Rd1d6 Qc7f7 a2a4 Ne6f4 g2g3 Nf4e6 Re1d1
     12	00:05	     379.629	95.302	+0.38	Bc4xe6 Nf4xe6 Rd1d6 Qc7f7 a2a4 Ne6f4 g2g3 Nf4h3+ Kg1g2 Nh3g5 Qf3g4
     13	00:08	     706.236	93.871	+0.43	Bc4xe6 Nf4xe6 Rd1d6 Qc7f7 a2a4 Ra8d8 a4a5 a7a6 Re1d1 Kh8g8 Bb2c3
     14	00:36	   3.334.885	95.436	+0.39	Bc4xe6 Nf4xe6 Rd1d6 Ra8e8 a2a4 Qc7c8 a4a5 Nc6e7 a5a6 b7xa6 c5c6 Ne7f5
     15	00:48	   4.504.708	97.495	+0.39	Bc4xe6 Nf4xe6 Rd1d6 Ra8e8 a2a4 Qc7c8 a4a5 Nc6e7 a5a6 b7xa6 c5c6 Ne7f5 Rd6d7
     16	01:22	   7.752.321	97.346	+0.40	Bc4xe6 Nf4xe6 Rd1d6 Ra8e8 a2a4 Qc7e7 Re1d1 Re8d8 Qf3d5 Ne6f4 Qd5c4 Rf8e8 g2g3 Nf4e6
     17	03:36	  21.089.275	96.065	+0.30	Bc4xe6 Nf4xe6 Rd1d6 Ra8e8 Qf3d5 Ne6f4 Qd5d1 Nf4e6 Qd1f3 Qc7c8 Re1d1 Ne6g5 Qf3d5 Re8d8
     18	07:02	  37.800.792	91.765	+0.32	Bc4xe6 Nf4xe6 Rd1d6 Ra8e8 Re1b1 Qc7c8 Nb3d2 Nc6e7 Nd2e4 Ne7f5 Rd6d1 Re8e7 Ne4d6 Qc8c6
     19	12:17	  66.176.381	91.989	+0.36	Bc4xe6 Nf4xe6 Rd1d6 Ra8e8 Re1d1 Qc7c8 Qf3g4 Kh8g8 Rd1d2 Re8e7 Bb2c3 Qc8e8 Qg4c4 Qe8f7
     20	18:21	  98.633.935	91.793	+0.38	Bc4xe6 Nf4xe6 Rd1d6 Ra8e8 Re1d1 Qc7c8 Qf3g4 Kh8g8 Rd1d2 Re8e7 Bb2c3 Qc8e8 Qg4c4 Qe8f7
     21	33:42	 184.715.708	93.581	+0.34	Bc4xe6 Nf4xe6 Rd1d6 Ra8e8 Re1d1 Qc7c8 Qf3g4 Rf8g8 a2a4 g6g5 a4a5 Rg8g6 a5a6 b7xa6
     22	1:53:04	 609.330.644	91.974	+0.32	Bc4xe6 Nf4xe6 Rd1d6 Ra8e8 a2a4 Qc7c8 a4a5 Ne6g5 Qf3e2 Re8e6 a5a6 b7xa6 Re1d1 Ng5f7
     23	2:34:24	 828.718.813	91.607	+0.32	Bc4xe6 Nf4xe6 Rd1d6 Ra8e8 a2a4 Qc7c8 a4a5 Ne6g5 Qf3e2 a7a6 f2f4 Ng5e6 f4xe5 Ne6f4
     24	4:29:39	1.450.526.408	91.808	+0.31	Bc4xe6 Nf4xe6 Rd1d6 Ra8e8 a2a4 Qc7c8 a4a5 Ne6g5 Qf3d3 Qc8g4 a5a6 Nc6b4 Qd3e2 Qg4xe2
   5/30/2008 2:05:51 AM, Time for this analysis: 05:00:01, Rated time: 5:00:00