Two Test Positions from Nogueiras

[Marc MP]

[D]1rqr2k1/pb3p2/n4b1p/3PN1p1/2pp4/P5P1/1PQB1PBP/2R1R1K1 w - - bm Nxf7; id "Nogueiras-Pogorelov (Alconbendas) 1994";

When I fill the hash from the won position and go backward, Chess Tiger 2007.1 gives +3.42 at depth 21 here. An additional difficulty is that Nxc4 is not as good as it looks.

[D]2rr2k1/pp1q1bp1/4p2p/2npP3/5N1P/1Q4P1/PP3P2/1BRR2K1 w - - bm Rxc5; id "Nogueiras- Campos Moreno (Moscow) 1994";

On this one Chess Tiger 2007.1 gives +1.24 at depth 25 when I force Rxc5.

Can your favorite engine solve one of these two?

[JVMerlino]

CM9_R1 finds the first move in under one second on a P4-3.0.

For the second position, my estimation is that it would find the move in approximately one hour at depth 14.

jm

[Marc MP]

...

For the second position, my estimation is that it would find the move in approximately one hour at depth 14.

jm

It is even better than this; 10 mintes and depth = 13 on my 2.4 P4 with 256M hash:

Code: Select all

 **CM9_R1**

...

4:14	1/12	0.55	43134590	1.b3-c3 d7-e8 2.g1-g2 b7-b6 3.b2-b4
					c5-d7 4.c3-d3 d7-f8 5.d3-a3 e8-e7
					6.f2-f3 c8xc1 7.d1xc1

8:03	1/13	0.42	79483315	1.b3-c3 d7-e8 2.g1-g2 c5-d7 3.c3-d3
					d7-f8 4.d3-a3 e8-b5 5.c1-c3 f8-d7
					6.a3-e7 d7xe5 7.f4xe6 d8-e8

10:19	1/13	1.02	104506637	1.c1xc5 c8xc5 2.b3-d3 g8-f8 3.d3-h7
					f7-g8 4.h7-h8 c5-c4 5.b1-h7 c4xf4
					6.h8xg8+ f8-e7 7.g8xg7+ f4-f7 8.g7xh6
					d7-a4 9.d1-c1 a4-d4 10.c1-c7+ d8-d7

11:58	2/14	0.95	125232758	1.c1xc5 c8xc5 2.b3-d3 g8-f8 3.d3-h7
					f7-g8 4.h7-h8 c5-c4 5.b1-h7 c4xf4
					6.h8xg8+ f8-e7 7.g8xg7+ f4-f7 8.g7xh6
					d7-a4 9.d1-c1 e7-d7 10.h7-g6

26:36	3/15	1.35	313116602	1.c1xc5 c8xc5 2.b3-d3 g8-f8 3.d3-h7
					d8-c8 4.h7-h8+ f8-e7 5.h8xg7 e7-d8
					6.g7xh6 d7-e7 7.g1-g2 d8-d7 8.b1-d3
					c5-a5 9.a2-a3

51:17	4/16	1.20	663119041	1.c1xc5 c8xc5 2.b3-d3 g8-f8 3.d3-h7
					f7-g8 4.h7-h8 c5-c4 5.b1-h7 c4xf4
					6.h8xg8+ f8-e7 7.g8xg7+ f4-f7 8.g7xh6
					d7-a4 9.d1-d2 d8-h8 10.h6-g5+ e7-d7
					11.h7-g6 f7-f8 12.b2-b3

[bedouin]

Using an internet search I was surprised that Chess Tiger is sold if it needs to be fed into hash to solve the positions above. Commercial engines normally have good evaluations.

[JVMerlino]

Yes, much better indeed! I didn't have time to wait, and some quick research led me to believe that the fail high would happen at depth 14 and take much longer to resolve. One depth sooner and six times faster!

Thanks for the information,
jm