Author: Robert Hyatt
Date: 06:05:57 12/23/98
Go up one level in this thread
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...
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