Author: blass uri
Date: 07:46:44 12/24/98
Go up one level in this thread
On December 24, 1998 at 10:24:13, Robert Hyatt wrote:
>On December 24, 1998 at 08:44:03, Ralph E. Carter wrote:
>
>>On December 23, 1998 at 09:05:57, Robert Hyatt wrote:
>>
>>>On December 23, 1998 at 04:24:09, Ralph E. Carter wrote:
>>>
>>>>On December 23, 1998 at 04:20:43, Alois Ganter wrote:
>>>>
>>>>>On December 23, 1998 at 03:17:29, Ralph E. Carter wrote:
>>>>>
>>>>>>Do you know that engines under Fritz and Junior have their hashtables cleared
>>>>>>before every move? And that this has a disproportionate effect on those engines
>>>>>>that intelligently save information between moves, like hiarcs and crafty?
>>>>>>
>>>>>>If nobody cares about questions such as these, I am leaving.
>>>>>
>>>>>I mailed Chessbase the question last week and they told me to try this
>>>>>experiment with Crafty as prove that it is decision of the engine alone what to
>>>>>do with hash tables: Take the second move of a position and let Crafty calculate
>>>>>some time. Then clip the analysis with search info from the search window to
>>>>>Notepad. Then go to the first move and let calculate for some time. Then go
>>>>>again to the second move and let calculate. Then clip analysis and compare with
>>>>>the first clip. Now the Crafty engine takes 25% less kN to find the same lines.
>>>>>I tried with the new 16.2 version from Chessbase download and it is right. And
>>>>>they say 16.2 is much stronger because Bob Hyatt corrected a problem in hash
>>>>>management.
>>>>>
>>>>>The Doctor? engine makes the same effect.
>>>>>
>>>>>Alois
>>>>
>>>>Posted by James T. Walker on December 22, 1998 at 19:47:21:
>>>>
>>>>Bob I hope you see this and can explain. This is the Crafty 15.20 inside of
>>>>Nimzo 99 and inside Junior appears to work the same way. Notice the times it
>>>>takes for Crafty to move. When this is run under Winboard Crafty plays the
>>>>entire variation in only a few seconds. Notice Crafty takes 72 seconds to make
>>>>the Mate in 1 move. Crafty searches 10 ply for that move but notice that is
>>>>typical of all the moves. It's a mate in 7 I created several years ago (18) to
>>>>test some of the old dedicated chess computers.
>>>>
>>>>Event "?"]
>>>>[Site "?"]
>>>>[Date "????.??.??"]
>>>>[Round "?"]
>>>>[White "Crafty 15.20"]
>>>>[Black "?"]
>>>>[Result "*"]
>>>>[Annotator "Crafty 15.20"]
>>>>[SetUp "1"]
>>>>[FEN "1k6/1P3p2/K7/8/8/8/7P/8 w - - 0 1"]
>>>>[PlyCount "13"]
>>>>
>>>>{59392kB, nzbook.CTG. PentiumII
>>>>} 1. Kb6 {#7/12 46} 1... f5 {11} 2. h4 {#6/14 31} 2... f4 {1}
>>>>3. h5{#5/12 40} 3... f3 {1} 4. h6 {#4/11 39} 4... f2 {1}
>>>>5. h7 {#3/11 38} 5... f1=Q {27} 6. h8=Q+ {#2/10 11} 6... Qf8 {3} 7. Qxf8# {#1/10
>>>>72} *
>>>>
>>>>Jim Walker
>>>
>>>No way to explain that. One point is that after I do a search and play a move
>>>that leads in mate, the next search terminates as soon as a shorter mate is
>>>found (to be sure I am making progress). But once I find a mate in 1 I should
>>>play it instantly unless something else is going on. It is certainly possible
>>>that the "new" command clears enough things to break this as well...
>>
>>Here are the results I get for this problem: (PII-300)
>>
>>Mate in: Time:
>>#7/12 34
>>#6/14 15
>>#5/12 15
>>#4/11 15
>>#3/9 14
>>#2/9 13
>>#1/9 25
>>
>
>what is that depth stuff above? I don't do "7/12" type searches and have no
>idea what that means nor where it is coming from. Or is that "mate in 7 found
>at ply=12"??
The mate in 7 was found before ply=12 but crafty under Chessbase interface feels
a duty to continue to search because it believes that it has to use the time
that you give it.
I do not know the reason for this.
Uri
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