Author: Uri Blass
Date: 02:36:19 06/17/01
Go up one level in this thread
On June 17, 2001 at 04:45:32, Frank Phillips wrote: >On June 17, 2001 at 04:11:26, Uri Blass wrote: > >>Are there top programs that are designed to see always simple tactics after >>enough time? >> >>Is it possible to change them to see always simple tactics after enough time >>when the price is only being 0.1% slower by using 2 engines when one engine is >>usually used only for only 0.1% of the time or maybe my math is wrong and only >>using another engine makes the program already more than 0.1% slower because of >>the fact that the program is bigger(even if the other engine is simply the >>original engine without null move pruning)? >> >>The position in the end of my post can happen in a game(it happened in an >>engine-engine game when I started from one of the position from my >>correspondence games). >> >>Deep Fritz could not see simple tactics because of null move pruning(with >>selectivity=0 Deep fritz has no problem to see more than 10 pawns advantage for >>black by Nc6 but with null move pruning Nc6 failed low again and again and fritz >>change it's mind to Ke3 when it is not clear if black can win after this move). >> >>I remember that Amir Ban said about other rare cases when Junior cannot see >>simple tactics that it is not a bug and I understand that he is not going to fix >>it so I wonder if there is a top program that is designed to see always simple >>tactics after enough time. >> >> >>New position >>[D]1n6/1P6/8/2P5/p3kp1p/6p1/1P4K1/4N3 b - - 0 1 >> >>Analysis by Deep Fritz: >> >>1...a3-- >> ³ (-0.31) Depth: 1/3 00:00:00 >>1...a3-- >> ³ (-0.31) Depth: 1/3 00:00:00 >>1...f3+! >> ³ (-0.38) Depth: 1/3 00:00:00 >>1...h3+! >> ³ (-0.50) Depth: 1/3 00:00:00 >>1...h3+! 2.Kxh3 >> µ (-0.91) Depth: 1/3 00:00:00 >>1...Nc6! >> -+ (-1.69) Depth: 1/3 00:00:00 >>1...Nc6! >> -+ (-2.13) Depth: 1/3 00:00:00 >>1...Nc6-- >> -+ (-1.81) Depth: 2/4 00:00:00 >>1...Nc6-- >> -+ (-1.81) Depth: 2/4 00:00:00 >>1...Kd4! >> -+ (-2.09) Depth: 2/6 00:00:00 >>1...Kd4! 2.Nf3+ >> -+ (-2.22) Depth: 2/6 00:00:00 >>1...Kd4 2.Nf3+ Kxc5 3.Nxh4 >> -+ (-2.22) Depth: 3/8 00:00:00 >>1...Kd4 2.Nf3+ Kxc5 3.Nxh4 Kd5 >> -+ (-2.22) Depth: 4/10 00:00:00 >>1...Kd4 2.Nf3+ Kxc5 3.Nxh4 Kc6 4.Ng6 >> -+ (-1.97) Depth: 5/11 00:00:00 >>1...Kd4-- >> -+ (-1.66) Depth: 6/12 00:00:00 2kN >>1...Kd4-- 2.Nf3+ Kxc5 3.Nxh4 Kc6 4.Ng6 Kxb7 >> -+ (-1.47) Depth: 6/13 00:00:00 2kN >>1...Kd5! >> -+ (-1.50) Depth: 6/13 00:00:00 2kN >>1...Kd5! 2.Nd3 Kd4 3.Nxf4 Kxc5 4.Ne6+ Kd6 >> -+ (-1.75) Depth: 6/13 00:00:00 3kN >>1...Nc6! >> -+ (-1.78) Depth: 6/13 00:00:00 4kN >>1...Nc6! 2.Kh3 f3 3.Nxf3 >> -+ (-2.13) Depth: 6/13 00:00:00 6kN >>1...Nc6 2.Kh3 f3 3.Nxf3 Kxf3 4.Kxh4 g2 >> -+ (-2.41) Depth: 7/15 00:00:00 8kN >>1...Nc6-- >> -+ (-2.09) Depth: 8/10 00:00:00 10kN >>1...Nc6-- >> -+ (-2.09) Depth: 8/18 00:00:00 12kN >>1...Nc6! >> -+ (-2.41) Depth: 9/17 00:00:00 28kN >>1...Nc6-- >> -+ (-2.09) Depth: 10/14 00:00:00 37kN >>1...Nc6-- >> -+ (-2.09) Depth: 10/19 00:00:00 45kN >>1...Nc6! >> -+ (-2.41) Depth: 11/20 00:00:00 87kN >>1...Nc6-- >> -+ (-2.09) Depth: 12/21 00:00:00 128kN >>1...Nc6-- >> -+ (-2.09) Depth: 12/24 00:00:00 172kN >>1...Nc6-- >> -+ (-1.78) Depth: 13/21 00:00:00 261kN >>1...Nc6-- >> -+ (-1.78) Depth: 13/26 00:00:00 377kN >>1...Nc6-- >> -+ (-1.47) Depth: 14/24 00:00:01 660kN >>1...Nc6-- >> -+ (-1.47) Depth: 14/28 00:00:01 922kN >>1...Nc6-- >> µ (-1.16) Depth: 15/27 00:00:02 1600kN >>1...Nc6-- >> µ (-1.16) Depth: 15/30 00:00:03 2180kN >>1...Nc6-- >> µ (-0.84) Depth: 16/29 00:00:05 3386kN >>1...Nc6-- >> µ (-0.84) Depth: 16/30 00:00:06 4622kN >>1...Ke3! >> µ (-0.88) Depth: 16/35 00:00:11 7839kN >>1...Ke3! 2.Nc2+ Kd3 3.c6 Nxc6 4.Nb4+ Ke2 5.Nxc6 f3+ 6.Kh3 f2 7.b8Q >> µ (-0.97) Depth: 16/39 00:00:13 9840kN, tb=1 >>1...Ke3 2.Nc2+ Kd3 3.c6 Nxc6 4.Nb4+ Ke2 5.Nxc6 f3+ 6.Kh3 f2 7.b8Q >> µ (-0.88) Depth: 17/37 00:00:23 17184kN, tb=4 >> >>(blass, telaviv 16.06.2001) >> >>Uri > > >Uri > >I am slightly confused: are you saying that Nc6 is wrong? No With null move on, my >program thinks it is a big win. I am saying that Ke3 is wrong Nc6 is the right move but Deep Fritz change it's mind to the wrong move because of null move pruning. It seems that Deep Fritz cannot see even a main line for Nc6 because of this null move pruning. I know that it is because of null move pruning because Deep Fritz has no problem to see that Nc6 is a big win without null move pruning. The fact that your program can see that Nc6 is a big win with null move proves nothing because your evaluation function may be different than Fritz's evaluation function. It also seems that Deep Fritz simply does not search the main line if it threats nothing and other programs use null move in a smarter way. Uri
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