Author: Uri Blass
Date: 13:15:46 01/15/01
Go up one level in this thread
On January 15, 2001 at 16:06:00, David Rasmussen wrote: >On January 15, 2001 at 10:07:42, Uri Blass wrote: > >>On January 15, 2001 at 08:33:46, David Rasmussen wrote: >> >>>On January 14, 2001 at 20:37:39, Djordje Vidanovic wrote: >>> >>>>On January 14, 2001 at 17:36:21, Dan Andersson wrote: >>>> >>>>>There is no problem. I suspect more than a few programs find Rxc6 in reasonable >>>>>times. The first program I tried actually found it quickly, the second too, >>>>>Crafty and Yace. Some others will find it later some sooner. Nothing tricky >>>>>about this position at all. >>>>> >>>>>Regards Dan Andersson >>>> >>>> >>>>Actually I believe that the position IS tough for some programs -- just look at >>>>the commercials listed that did not find the winning move. Of the programs that >>>>I tested the quickest was Patzer 3.11b which found 1.Rxc6 in a second! Also >>>>quick were Deep Fritz (about 20 sec), Gandalf 4.32g (20 sec), Ikarus (around 25 >>>>sec), Fritz 5.32 (about 25 sec too), etc. Some other programs could not find >>>>the sequence at all. The issue here is mobility, I suspect. I had thought that >>>>Phalanx would be fast, but after a minute passed and it had no clue, I gave it >>>>up. >>>> >>>>*** Djordje >>> >>>I don't understand why this can be hard. My program Chezzz is definitely weaker >>>than DF, Gandalf, Fritz 5.32, and probably some or all of the others you >>>mention, but still, Rxc6 is the _only_ move it ever considers, even at depth=1. >>>It never considers any other move at all. This takes 0.02 seconds on my Cel 464. >> >>I do not understand why your program considers Rxc6 even at depth 1 because this >>move is losing material at depth 1. >>I suspect that your program is not materialistic enough and can play sacrifices >>that are not correct. >> >>Uri > >Chezzz is not very positional. It is fairly materialistic (unfortunately). >Accumulated positional scores stay well below one pawn in most positions, and in >this one too. >Judge for yourself. > >Thinking for 11 seconds. >time depth val variation >0.01 1/2 -2.32 32. Rxc6 dxc6 (0 kN) >0.01 1/2 -----> 36 nodes 3600 nps q 11% mo 50% h 0% >0.02 2/3 -2.32 32. Rxc6 dxc6 (0 kN) >0.03 2/3 -----> 176 nodes 5866 nps q 14% mo 93% h 0% >0.04 3/5 -2.32 32. Rxc6 dxc6 33. Rd3 (0 kN) >0.06 3/5 -----> 1271 nodes 21183 nps q 9% mo 89% h 0% >0.06 4/7 -2.32 32. Rxc6 dxc6 33. Rd3 Rb4 (1 kN) >0.10 4/7 -----> 4513 nodes 45130 nps q 13% mo 86% h 6% What is the score for Ra2 or R6d3 at depthes 1-4? After these moves white is only a pawn down so the score should be 1 pawn for black and not 2 pawns for black unless your program can see big positional advantage for black and not only a pawn. Uri
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