A very complex tactical position

[YL84]

It was reached during openwar 3, Milady 2.22 - Bestia 0.9
White missed here a tactical shot , easy to find by humans. Though the issue is not so clear, have not verified with strong chess engine.

[d] r3rnk1/1bq1bp1n/pp1pp1pQ/6P1/2PN3B/2NBP3/PP5P/2R2RK1 w - - 0 15


Enjoy
yves

[David Dahlem]

Here's what TheKing 3.50 thinks ...

DualIntel P4 3GHz - 256mb hash

FEN: r3rnk1/1bq1bp1n/pp1pp1pQ/6P1/2PN3B/2NBP3/PP5P/2R2RK1 w - - 0 15

TheKing 3.50:
3 00:00 2.483 82.766 +1.16 Nc3e4 e6e5 Ne4f6+ Nh7xf6 g5xf6
4 00:00 9.920 124.000 +1.16 Nc3e4 e6e5 Ne4f6+ Nh7xf6 g5xf6
5 00:00 51.533 147.237 +1.70 Nc3e4 Bb7xe4 Bd3xe4 Qc7c5 Be4xa8 Re8xa8 b2b4 Qc5xb4
6 00:00 75.446 153.971 +1.70 Nc3e4 Bb7xe4 Bd3xe4 Qc7c5 Be4xa8 Re8xa8 b2b4 Qc5xb4
6 00:00 88.996 161.810 +4.26 Rf1xf7 Kg8xf7 Bd3xg6+ Kf7g8 Bg6xh7+ Nf8xh7 Nd4xe6 Be7f8 Qh6g6+ Qc7g7 Ne6xg7 Bf8xg7 Qg6xd6
7 00:00 136.848 175.446 +4.26 Rf1xf7 Kg8xf7 Bd3xg6+ Kf7g8 Bg6xh7+ Nf8xh7 Nd4xe6 Be7f8 Qh6g6+ Qc7g7 Ne6xg7 Bf8xg7 Qg6xd6
8 00:01 256.617 192.945 +4.65 Rf1xf7 Kg8xf7 Bd3xg6+ Kf7g8 Bg6xh7+ Nf8xh7 Nd4xe6 Be7f8 Qh6g6+ Qc7g7 Ne6xg7 Bf8xg7 Rc1f1
9 00:03 665.154 213.875 +2.64 Rf1xf7 Kg8xf7 Bd3xg6+ Kf7g8 Bg6xh7+ Nf8xh7 Nd4xe6 Be7xg5 Qh6g6+ Kg8h8 Ne6xc7 Re8g8 Qg6xd6 Bg5xh4+ Kg1f1
10 00:10 2.418.917 226.702 +1.89 Rf1xf7 Kg8xf7 Bd3xg6+ Kf7g8 Bg6xh7+ Nf8xh7 Nd4xe6 Be7xg5 Qh6g6+ Kg8h8 Ne6xc7 Re8g8 Qg6f7 Bg5xh4+ Kg1f1
11 01:33 19.663.422 211.707 +1.12 Rf1xf7 Kg8xf7 Bd3xg6+ Kf7g8 Bg6xe8 Ra8xe8 Rc1f1 Qc7xc4 g5g6 Qc4d3 Bh4xe7 Qd3xg6+ Qh6xg6+ Nf8xg6 Be7xd6 Nh7g5
11 02:12 27.138.401 204.725 +1.61 Rc1c2 e6e5 Rf1xf7 Kg8xf7 Bd3xg6+ Kf7g8 Bg6xh7+ Nf8xh7 Nd4e6 Be7xg5 Qh6g6+ Kg8h8 Ne6xc7 Re8g8 Qg6xd6 Bg5xh4+ Kg1f1
11 03:23 41.341.083 203.510 +2.00 Rf1f6 Qc7c5 Rc1f1 Qc5e5 Rf1f2 Qe5xe3 Rf6xf7 Qe3xd4 Bd3xg6 Nh7xg5 Bh4xg5
12 05:12 65.508.200 209.518 +1.74 Rf1f6 Qc7c5 Rc1f1 Qc5e5 Rf1f2 Qe5xe3 Rf6xf7 Qe3xd4 Bd3xg6 Nh7xg5 Bh4xg5 Qd4g4+ Kg1f1 Qg4xc4+ Kf1g1
13 15:12 192.569.492 211.127 +2.59 Rf1f6 Qc7c5 Nc3d5 Bb7xd5 Rc1f1 Nh7xg5 Bh4xg5 Bd5xc4 Bd3xc4 Qc5e5 Nd4c6 Qe5c5 Nc6xe7+ Re8xe7 Rf6f2 Re7c7

Regards
Dave

[YL84]

It seems even more complex than I thought at the beginning , my engine only considering Rxf7 at depth 12
Yves

[Jaimes Conda]

It was reached during openwar 3, Milady 2.22 - Bestia 0.9
White missed here a tactical shot , easy to find by humans. Though the issue is not so clear, have not verified with strong chess engine.

[d] r3rnk1/1bq1bp1n/pp1pp1pQ/6P1/2PN3B/2NBP3/PP5P/2R2RK1 w - - 0 15


Enjoy
yves

Fritz 9 : 13hrs +4.16 depth 20/20.....Rf6!
Rybka Beta 1.0 : 13hrs +3.49 depth 19.....Rf6 - d5

Jaimes

[Roman Hartmann]

Roce likes to sac rooks. Although up from ply 10 the score is dropping for Rxf7.

Code: Select all

roce: setboard r3rnk1/1bq1bp1n/pp1pp1pQ/6P1/2PN3B/2NBP3/PP5P/2R2RK1 w - - 0 15

roce: analyze

 D.   Time    Score  Best line
  1   0.18    0.35   Nc3-e4 
  2   0.19    0.57   Nc3-e4 bb7xe4 
  3   0.31    0.37   b2-b4 nf8-d7 a2-a4 
  4   0.39    0.46   Bd3-e4 nf8-d7 Be4xb7 qc7xb7 
  5   0.92    0.47   Nc3-e4 e6-e5 Nd4-f3 nf8-e6 Bh4-f2 
  6   1.79    1.10   Rf1xf7 kg8xf7 Bd3xg6+ kf7-g8 Nd4xe6 be7xg5 Ne6xc7 
  7   4.56    1.82   Rf1xf7 kg8xf7 Bd3xg6+ kf7-g8 Bg6xh7+ kg8-h8 Nd4xe6 
                     be7xg5 Ne6xc7 
  8  18.90    3.81   Rf1xf7 kg8xf7 Bd3xg6+ kf7-g8 Bg6xh7+ nf8xh7 Nd4xe6 
                     be7-f8 Qh6-g6+ qc7-g7 Ne6xg7 
  9   1:04    3.81   Rf1xf7 kg8xf7 Bd3xg6+ kf7-g8 Bg6xh7+ nf8xh7 Nd4xe6 
                     be7-f8 Qh6-g6+ qc7-g7 Ne6xg7 bf8xg7 
 10   3:44    3.40   Rf1xf7 kg8xf7 Bd3xg6+ kf7-g8 Bg6xh7+ nf8xh7 Nd4xe6 
                     be7xg5 Qh6-g6+ kg8-h8 Ne6xc7 re8-g8 Qg6xd6 
 11  14:17    1.89   Rf1xf7 kg8xf7 Bd3xg6+ kf7-g8 Bg6xh7+ nf8xh7 Nd4xe6 
                     be7xg5 Qh6-g6+ kg8-h8 Ne6xc7 re8-g8 Qg6-f7 bg5xe3+ 
                     Kg1-f1 bb7-g2+ Kf1-e2 

[YL84]

Well, it seems you have to reach at least depth 11/12 before to switch to Rf6 which looks better than Rxf7. My engine can not find it even at depth 12, but it's not the King !

Code: Select all

"depth 1 score 190 temps 1 nbnod 56 B_F :55 :  b2b3"
"depth 2 score 40 temps 15 nbnod 427 B_F :19,2613602842582 :  h4g3 f7f5"
"depth 3 score 160 temps 48 nbnod 4195 B_F :15,5609807229628 :  c3e2 f7f6 d4c2"
"depth 4 score 220 temps 187 nbnod 17663 B_F :10,7727300444795 :  c3e4 e6e5 e4f6 e7f6"
"depth 5 score 90 temps 640 nbnod 56104 B_F :8,25959847406069 :  c3e4 c7d7 e4g3 d7a4 h2h3"
"depth 6 score 160 temps 944 nbnod 85806 B_F :5,56498864205606 :  c3e4 e6e5 e4f6 e7f6 g5f6 g8h8"
"depth 7 score 160 temps 2623 nbnod 320841 B_F :5,85200446098253 :  c3e4 e8c8 e4g3 c8e8 c1c2 e6e5 d4e2"
"depth 8 score 220 temps 5913 nbnod 689043 B_F :4,96318847769408 :  c3e4 b7e4 d3e4 a8c8 e4c6 f8d7 f1f7 g8f7"
"depth 9 score 220 temps 17488 nbnod 2552412 B_F :4,97393234807627 :  c3e4 b7e4 d3e4 a8c8 e4c6 e8d8 c6e4 d6d5 c4d5"
"depth 10 score 210 temps 31931 nbnod 4051402 B_F :4,14552819787273 :  c3e4 b7e4 d3e4 a8c8 e4c6 e6e5 c6e8 c8e8 d4e2 f7f5"
"depth 11 score 320 temps 84869 nbnod 13969038 B_F :4,32550786352578 :  f1f7 g8f7 d3g6 f7g8 g6h7 f8h7 d4e6 e7f8 h6g6 c7g7 e6g7"
"depth 12 score 320 temps 148686 nbnod 21337882 B_F :3,73493699629248 :  f1f7 g8f7 d3g6 f7g8 g6h7 f8h7 d4e6 e7f8 h6g6 c7g7 e6g7 f8g7"

Yves

[Andrew]

This is unusual. Rybka 2.3.2a on normal settings will go for Rc2:


r3rnk1/1bq1bp1n/pp1pp1pQ/6P1/2PN3B/2NBP3/PP5P/2R2RK1 w - - 0 1

Analysis by Rybka 2.3.2a 32-bit :

15.Rc2 e5 16.Nd5 Qc8 17.Nf3 Qh3 18.Bg3 Qxh6 19.gxh6
+/- (1.04) Depth: 5 00:00:00
15.Rxf7 Kxf7 16.Bxg6+ Kg8 17.Bxh7+ Nxh7 18.Nxe6
+- (3.33) Depth: 5 00:00:00
15.Rxf7 Kxf7 16.Bxg6+ Kg8 17.Bxh7+ Nxh7 18.Nxe6 Bxg5 19.Qg6+ Kh8 20.Nxc7 Rg8 21.Qf7 Bxe3+ 22.Kf1 Bxc1 23.Nxa8 Bxa8
+- (2.39) Depth: 5 00:00:00
15.Rxf7 Kxf7 16.Bxg6+ Kg8 17.Bxh7+ Nxh7 18.Nxe6 Bxg5 19.Qg6+ Kh8 20.Nxc7 Rg8 21.Qf5 Bxe3+ 22.Kf1 Bxc1 23.Nxa8 Bxa8
+- (2.21) Depth: 6 00:00:00 13kN
15.Rxf7 Kxf7 16.Bxg6+ Kg8 17.Bxh7+ Nxh7 18.Nxe6 Bxg5 19.Qg6+ Kh8 20.Nxc7 Rg8 21.Qb1 Bxh4+ 22.Kf1 Raf8+ 23.Ke2 Rg2+ 24.Kd1 Bf3+
+/- (1.25) Depth: 7 00:00:00 17kN
15.Rxf7 Kxf7 16.Bxg6+ Kg8 17.Bxh7+ Nxh7 18.Nxe6 Bxg5 19.Qg6+ Kh8 20.Nxc7 Rg8 21.Qb1 Bxh4+ 22.Kf1 Raf8+ 23.Ke2 Rg2+ 24.Kd3 Rxh2 25.N3d5
+- (1.50) Depth: 8 00:00:01 29kN
15.Rxf7 Kxf7 16.Bxg6+ Kg8 17.Bxh7+ Nxh7 18.Nxe6 Bxg5 19.Qg6+ Kh8 20.Nxc7 Rg8 21.Qb1 Bxh4+ 22.Kf1 Raf8+ 23.Ke2 Rg2+ 24.Kd3 Rff2 25.N3d5 Rxb2
+/- (1.24) Depth: 9 00:00:01 45kN
15.Rxf7 Kxf7 16.Bxg6+ Kg8 17.Bxh7+ Nxh7 18.Nxe6 Bxg5 19.Qg6+ Kh8 20.Nxc7 Rg8 21.Qb1 Bxh4+ 22.Kf1 Raf8+ 23.Ke2 Rg2+ 24.Kd3 Rff2 25.Na4 Rd2+ 26.Kc3 Bf6+ 27.Kb3 Rxh2
+/- (1.07) Depth: 10 00:00:05 144kN
15.Rxf7 Kxf7 16.Bxg6+ Kg8 17.Bxe8 Rxe8 18.Rf1 Qc8 19.Rf4 e5 20.Nf5 Ne6 21.g6 Nhf8 22.Nxe7+ Rxe7 23.Bf6 exf4 24.Qh8#
+/- (0.78) Depth: 11 00:00:20 649kN
15.Be4 Qd7 16.Rf2 e5 17.Bxb7 Qxb7 18.Rcf1 Bxg5 19.Bxg5 exd4 20.Rxf7 Qxf7 21.Rxf7 Kxf7 22.exd4 Rac8 23.Bh4 Rxc4 24.Qf4+ Kg8 25.Qxd6 Ne6 26.Qd7
+/- (0.86) Depth: 11 00:00:30 922kN
15.Be4 Qd7 16.Rf2 e5 17.Bxb7 Qxb7 18.Rcf1 Bxg5 19.Bxg5 exd4 20.Rxf7 Qxf7 21.Rxf7 Kxf7 22.exd4 Rac8 23.Bh4 Rxc4 24.Qf4+ Kg7 25.Qxd6 Re6 26.Qd5 Rc7
+/- (0.97) Depth: 12 00:01:01 1866kN
15.Be4 Qd7 16.Rf2 e5 17.Bxb7 Qxb7 18.Rcf1 Bxg5 19.Bxg5 exd4 20.Rxf7 Qxf7 21.Rxf7 Kxf7 22.exd4 Rac8 23.Bh4 Rxc4 24.Qf4+ Kg7 25.Qxd6 Re6 26.Qd5 Rc7 27.Qf3
+/- (0.96) Depth: 13 00:01:27 2747kN
15.Be4 Qd7 16.Rf2 e5 17.Bxb7 Qxb7 18.Rcf1 Bxg5 19.Bxg5 exd4 20.Rxf7 Qxf7 21.Rxf7 Kxf7 22.exd4 Rac8 23.Bh4 Rxc4 24.Qf4+ Kg7 25.Qxd6 Re6 26.Qd5 Rc7 27.Qd8 Rf7
+/- (0.91) Depth: 14 00:02:22 4712kN
15.Rc2 Qd7 16.Rcf2 Nxg5 17.Bxg5 f5 18.h4 Bxg5 19.Qxg5 Qe7 20.Nf3 Qxg5+ 21.hxg5 Nd7 22.Rd2 Bxf3 23.Rxf3 Ne5 24.Rf4 Rac8 25.Be2 Rc6 26.Kg2
+- (1.81) Depth: 14 00:04:12 7911kN
15.Rc2 Qd7 16.Rcf2 Nxg5 17.Bxg5 f5 18.h4 Bxg5 19.Qxg5 Qe7 20.Nf3 Qxg5+ 21.hxg5 Nd7 22.Rd2 Bxf3 23.Rxf3 Ne5 24.Rf4 Rac8 25.Be2 Rc6 26.Kg2 Kg7
+- (1.80) Depth: 15 00:05:57 10975kN

(, 06.11.2007)

However change the outlook parameter and it can be very different!

Andrew

[Terry McCracken]

It was reached during openwar 3, Milady 2.22 - Bestia 0.9
White missed here a tactical shot , easy to find by humans. Though the issue is not so clear, have not verified with strong chess engine.

[d] r3rnk1/1bq1bp1n/pp1pp1pQ/6P1/2PN3B/2NBP3/PP5P/2R2RK1 w - - 0 15


Enjoy
yves

It's very easy, it surprised me that a computer would find this position difficult

Terry

[dts]

Hi,
Here is Analysis with my program,which is called Styx
well not much differant here :-S,
My Engine just like Yves' & Roman's engine thinks only of rook sac.....

Code: Select all

setboard r3rnk1/1bq1bp1n/pp1pp1pQ/6P1/2PN3B/2NBP3/PP5P/2R2RK1 w - - 0 15
analyse

Time	D	Score	Principal Variation

0.00	1	-2.78	Bd3xg6 Nf8xg6
0.00	1	+1.41	Rf1-f2
0.00	1	+1.92	Bd3-e4
0.00	1	+2.44	Nc3-e4
0.00	2	+2.01	Nc3-e4 Pe6-e5
0.00	3	+1.97	Nc3-e4 Pe6-e5 Nd4-b3
0.02	4	+1.55	Nc3-e4 Pe6-e5 Nd4-b3 Nf8-e6
0.05	4	+1.68	Bd3-e4 Bb7xe4 Nc3-e4 Nf8-d7
0.21	5	+1.86	Bd3-e4 Ra8-c8 Pb2-b3 Pd6-d5 Pc4xd5 Pe6xd5
0.57	6	+1.64	Bd3-e4 Bb7xe4 Nc3xe4 Pe6-e5 Ne4-f6 Be7xf6 Pg5xf6
0.80	6	+2.50	Nc3-e4 Bb7xe4 Bd3xe4 Ra8-c8 Nd4-c6 Nf8-d7
0.96	6	+5.34	Rf1xf7 Kg8-f7 Bd3xg6 Kf7-g8 Bg6-h7 Kg8-h8 Bh7-g6 Kh8-g8 Nd4xe6
1.22	7	+5.70	Rf1xf7 Kg8-f7 Bd3xg6 Kf7-g8 Bg6-h7 Nf8xh7 Nd4xe6 Be7-f8 Qh6-g6 Qc7-g7 Ne6xg7 Bf8xg7 Qg6xd6
1.67	8	+5.70	Rf1xf7 Kg8-f7 Bd3xg6 Kf7-g8 Bg6-h7 Nf8xh7 Nd4xe6 Be7-f8 Qh6-g6 Qc7-g7 Ne6xg7 Bf8xg7 Qg6xd6
2.91	9	+5.70	Rf1xf7 Kg8-f7 Bd3xg6 Kf7-g8 Bg6-h7 Nf8xh7 Nd4xe6 Be7-f8 Qh6-g6 Qc7-g7 Ne6xg7 Bf8xg7 Qg6xd6
7.38	10	+3.72	Rf1xf7 Kg8-f7 Bd3xg6 Kf7-g8 Bg6-h7 Nf8xh7 Nd4xe6 Be7-g5 Qh6-g6 Kg8-h8 Ne6xc7 Re8-g8 Qg6-f7 Bg5xe3 Kg1-f1 Be3xc1 Nc7xa8 Bb7xa8
15.34	11	+3.72	Rf1xf7 Kg8-f7 Bd3xg6 Kf7-g8 Bg6-h7 Nf8xh7 Nd4xe6 Be7-g5 Qh6-g6 Kg8-h8 Ne6xc7 Re8-g8 Qg6-f7 Bg5xe3 Kg1-f1 Be3xc1

For all of you.... before you ask me
Styx is still pretty young & very buggy, & I do not plan to release it anytime soon,perhaps after i am satisfied with it

Regards,
David

[BBauer]

What do you mean by "very simple"?
There are many good moves for white.
1. b4, 1. Be4, 1. Rxf7, 1. Rc1c2, 1. Rf6.
Perhaps 1. Rf1f6 is the best move, but I am not shure.

This "very simple" is a typical patzer statement usually based on
poor or no analysis.
kind regards
Bernhard