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Subject: Re: very difficult Uri test position

Author: Uri Blass

Date: 02:50:24 02/10/02

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On February 09, 2002 at 23:13:30, K. Burcham wrote:

>This turned out to be a very difficult test position.
>Deep Shredder6 in over 22 hours on 3100 mhz will not play Nxf2.
>Chess Tiger 14.0 1000mhz in over 21 hours will not play Nxf2.
>Fritz7 1507 mhz in over 20 hours will not play Nxf2.
>
>if i make the first move Nxf2, then Deep Shredder6 will make the next move in
>this line  Nxf2 Kxf2 Bh4 g3 f4. and will play each move in this line. so Deep
>Shredder6 agrees with this line.
>
>So with this line, it seems the depth is about 10 until Shredder6 sees the line
>is winning for black.          Nxf2 Kxf2 Bh4 g3 f4 4.Kg2 fxg3 5.hxg3 Bxg3 6.Rh1
>Bh4 7.Nf1 Qf6 8.Bxh7+ Kh8 9.Bd3 Rae8 10.Kg1 Be2 11.Bf5 (224.630.445) 575.2
>13.01	 6:30 	-0.85   (did i count right here)  but with 20 hours at depth 19
>Deep Shredder6 will not play Nxf2.
>
>
>[D] r2q1rk1/ppp1b1pp/2n5/3p1p2/3Pn1b1/2PB4/PPQN1PPP/RNB1R1K1 b - - 0 1
>
>black won by Nxf2 Kxf2 Bh4+ g3 f4
>I will try to give a more detailed analysis of this position but I remember that
>black can win it against every defence of white
>It is difficult even after f4 for programs to see that white is losing and
>Junior5 after some hours in the position after f4 evaluates the position as 0.19
>pawns advantage for white.
>
>Uri
>
>
>Shredder 6:    2x1533mhz    512 hash
> 16.01	34:23 	+0.31 	1...Bd6 2.Nf1 Qh4 3.Na3 a6 4.h3 Bh5 5.Be3 f4 6.Bc1 Bxa3
>7.bxa3 Bg6 8.Nh2 (965.481.550) 467.9
> 17.01	111:09 	+0.54 	1...Bd6 2.Nf1 Qh4 3.Na3 a6 4.Re3 f4 5.Bxe4 fxe3 6.Bxd5+
>Kh8 7.Bxe3 Rad8 8.Bxc6 bxc6 (3.178.285.525) 476.5
> 18.01	421:46 	+0.76 	1...Bd6 2.Nf1 Qh4 3.b3 Rf6 4.Ng3 Kh8 5.a3 Rff8 6.a4 Rae8
>7.Bxe4 fxe4 8.Ba3 Be7 (12.249.550.309) 484.0
> 19.01	1226:56 	+0.89 	1...Bd6 2.Nf1 Qh4 3.a4 Kh8 4.b3 Rf6 5.Ng3 g5 6.Re3 Rh6
>7.h3 Bf4 8.Re1 Bxh3 (36.663.667.488) 498.0
>best move: Be7-d6 time: 1372:22.985 min  n/s: 511.653  CPU 199.9%  nodes:
>42.131.054.127  depth 19
>
>Chess Tiger 14.0      1000mhz   192 hash
>02:01:10.8	-0.12	18	1727643107	Bd6 Nf1 Qh4 Na3 a6 Re3 Nf6 Re6 f4 Rxd6 cxd6 Bxf4
>Rad8 Re1 Bf5 Bxf5 Qxf4 Be6+ Kh8
>09:41:35.9	0.16	19	40158732	Bd6 Nf1 Qh4 Na3 a6 Re3 Nf6 Bxf5 Bxf5 Qxf5 Ng4 Qxd5+
>Kh8 g3 Nxe3 Nxe3 Qf6 f4 Qg6
>21:31:56.1	0.16	20	-2024641247	Bd6 Nf1 Qh4 Na3 a6 Re3 Nf6 Bxf5 Bxf5 Qxf5 Ng4
>Qxd5+ Kh8 g3
>
>Fritz7:   1507 mhz    256 hash
>1...Bd6 2.Nf1 Qh4 3.Re3 Nf6 4.f3 f4 5.Re2 Bh5 6.b3 Rae8 7.Ba3
>  (-.38)    Depth: 18/48  05:47:07   14824155kN
>1...Bd6 2.Nf1
>  (-.41)    Depth: 19/52  14:00:51   36310193kN
>  (over 20 hours did not update analysis)
>
>
>After:    Nxf2    Kxf2   Bh4   g3    f4
> [D] r2q1rk1/ppp3pp/2n5/3p4/3P1pbb/2PB2P1/PPQN1K1P/RNB1R3 w - - 0 1
>
>Fritz 7:        1507 mhz      192 hash
>4.Kg2 fxg3 5.Bxh7+ Kh8 6.hxg3 Be7
>  +-  (2.63)   Depth: 8/28   00:00:00  319kN
>4.Kg2 f3+
>  +-  (2.44)   Depth: 9/32   00:00:01  1303kN
>4.Bxh7+ Kh8 5.Kg2 Qd7 6.gxh4
>  +-  (2.44)   Depth: 9/32   00:00:02  1622kN
>4.Bxh7+--
>  +-  (2.16)   Depth: 10/30   00:00:03  2529kN
>4.Bxh7+ Kh8 5.Kg2 fxg3 6.hxg3 Qd6 7.Nf1 Rxf1
>  +-  (2.13)   Depth: 10/33   00:00:04  3022kN
>4.Kg2!
>  +-  (2.16)   Depth: 10/33   00:00:05  3446kN
>4.Kg2 fxg3 5.hxg3 Qd6 6.gxh4 Rf2+ 7.Kxf2 Qh2+ 8.Ke3 Qh3+ 9.Nf3 Qxf3+ 10.Kd2
>  +-  (2.19)   Depth: 10/33   00:00:05  3928kN
>4.Kg2 fxg3 5.Bxh7+ Kh8 6.hxg3 Qd6 7.Nf1
>  +-  (2.13)   Depth: 11/33   00:00:14  10201kN
>4.Kg2--
>  +-  (1.85)   Depth: 12/36   00:00:23  15913kN
>4.Kg2 fxg3 5.Bxh7+ Kh8 6.hxg3 Bh3+ 7.Kxh3 Bxg3 8.Nf3 Rxf3 9.Kg2 Bxe1 10.Kxf3
>  +-  (1.82)   Depth: 12/39   00:00:33  23370kN
>4.Kg2--
>  +-  (1.54)   Depth: 13/40   00:01:09  49143kN
>4.Kg2 fxg3 5.Rf1 gxh2 6.Bxh7+ Kh8 7.Kh1 Qd6
>  ±  (1.00)   Depth: 13/44   00:01:54  81088kN
>4.Kg2!
>  ±  (1.29)   Depth: 14/44   00:05:14  225140kN
>4.Kg2 fxg3 5.hxg3 Bxg3 6.Bxh7+ Kh8 7.Rh1 Bh4 8.Qg6 Rf2+ 9.Kg1 Qe7 10.Ne4 Bf5
>  ±  (1.32)   Depth: 14/44   00:06:40  287765kN
>4.Kg2--
>  ±  (1.04)   Depth: 15/43   00:10:58  474202kN
>4.Kg2 fxg3 5.hxg3 Bxg3 6.Rh1 Qf6 7.Bxh7+ Kh8 8.Bg8+ Kxg8
>  µ  (-0.90)   Depth: 15/50   00:40:12  1732610kN
>4.Kg1!
>  µ  (-0.87)   Depth: 15/50   00:46:20  2000417kN
>4.Kg1 fxg3 5.Nf1 gxh2+ 6.Qxh2 Bf2+ 7.Kg2 h5 8.Re2 Qf6
>  µ  (-0.84)   Depth: 15/50   00:48:36  2101317kN
>
>
>Shredder6:        2x1533 mhz            512 hash
> 12.01	 1:15 	+1.42 	4.Kg2 fxg3 5.hxg3 Bxg3 6.Bxh7+ Kh8 7.Rh1 Bh4 8.Qg6 Rf4
>9.Rf1 Bf5 10.Qxf5 Rxf5 11.Bxf5 (43.479.086) 578.9
> 13.01	 2:03 	+1.17--	4.Kg2 fxg3 5.hxg3 Bxg3 6.Bxh7+ Kh8 7.Rh1 Bh4 8.Qg6 Rf4
>9.Rf1 Qf8 10.Rxf4 Qxf4 11.Kh1 Bf3+ 12.Nxf3 Qxc1+ 13.Ng1 Qxb2 14.Qg5 (70.624.732)
>572.2
> 13.01	 2:24 	+0.67--	4.Kg2 fxg3 5.hxg3 Bxg3 6.Bxh7+ Kh8 7.Rh1 Bh4 8.Qg6 Rf4
>9.Rf1 Qf8 10.Rxf4 Qxf4 11.Kh1 Bf3+ 12.Nxf3 Qxc1+ 13.Kg2 Qxb2+ 14.Qc2 Qxa1
>15.Nxh4 (82.450.456) 569.9
> 13.01	 6:30 	-0.85 	4.Kg2 fxg3 5.hxg3 Bxg3 6.Rh1 Bh4 7.Nf1 Qf6 8.Bxh7+ Kh8
>9.Bd3 Rae8 10.Kg1 Be2 11.Bf5 (224.630.445) 575.2
> 14.01	21:15 	-0.93 	4.Kg2 fxg3 5.hxg3 Bxg3 6.Rh1 Bh4 7.Nf1 Qf6 8.Be3 Bf3+ 9.Kg1
>Bxh1 10.Kxh1 Qf3+ 11.Qg2 Rae8 12.Nbd2 Qxg2+ 13.Kxg2 Ne7 (752.907.205) 590.1
> 15.01	43:15 	-1.18--	4.Kg2 fxg3 5.hxg3 Bxg3 6.Rh1 Bh4 7.Nf1 Qf6 8.Be3 Rae8
>9.Kg1 Rxe3 10.Bxh7+ Kh8 11.Be4 Rxe4 12.Nbd2 (1.542.308.200) 594.1
> 15.01	51:49 	-1.68--	4.Kg2 fxg3 5.hxg3 Bxg3 6.Rh1 Bh4 7.Nf1 Qf6 8.Be3 Rae8
>9.Kg1 Rxe3 10.Bxh7+ Kh8 11.Nxe3 Bf2+ 12.Kf1 Qf3 13.Be4+ Bh3+ 14.Ng2
>(1.844.461.791) 593.2
> 15.01	68:02 	-1.72 	4.Kg2 fxg3 5.hxg3 Bxg3 6.Rh1 Bh4 7.Nf1 Qf6 8.Be3 Rae8 9.Kg1
>Rxe3 10.Bxh7+ Kh8 (2.464.855.967) 603.8
>kburcham


Interesting that both Fritz and shredder did not find Bh3+ in their main line
when Bh3+ was played in the game that the position is from it(asi alperopvich
was black and he is even not a master):

Here is the game line:
11...Nxf2 12.Kxf2 Bh4+ 13.g3 f4 14.Kg2 fxg3 15.hxg3
Bh3+ 16.Kxh3 Bxg3 17.Bxh7+ Kh8 18.Nf3 Rxf3 19.Rh1 Bf4+ 20.Kg2 Qg5+


Yace cannot see positive score for black but after 2 hours it can find the game
line

I do not know if Bh3+ is the fastest way to win but yace likes it at depth 14.
I remember that I verified that 5...Bh3+ is good for black at that time.

4.Kg2 fxg3 5.hxg3 Bh3+ 6.Kxh3 Bxg3 7.Nf3 Rxf3 8.Bxh7+ Kh8 9.Kg2 Qf6 10.Re2 Bd6
11.Re3 Rf1 12.Bd3 Rf8
  ²  (0.62)   Depth: 14   01:55:28  2508868kN

Uri



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