Author: Dave Gomboc
Date: 21:48:54 04/07/99
Go up one level in this thread
On April 03, 1999 at 23:20:15, James Swafford wrote:
>On April 03, 1999 at 18:26:33, William Bryant wrote:
>
>>I recently ran (for the first time) the LCTII test suite against my program in
>>two forms, one with a PVS search and one without. The version without scored
>>better in a few positions. At no point did the PVS code make it to a deeper ply
>>in the 10 minute time frame than the non-PVS search.
>>(Score of 2090 for PVS to 2120 without PVS).
>>
>>I do not have Null moves implemented yet.
>>
>>I know PVS is very sensitive to move ordering. I am sorting moves as follows.
>>1. Hash Table Moves
>>2. PV Move (if not the same as Hash table move)
>>3. Captures and Promotions
>>4. History moves
>>5. All other moves
>>
>>I do not have killer moves added yet
>
>A couple of things to think about:
>
>Try placing the pv move first. After all, a previous search
>determined that move was best. PVS works best in cases that
>the best move is searched first, and all others are fail
>quickly.
>
>Try putting losing captures after the non captures.
>
>
>>
>>My questions are:
>>1) Does null move pruning help PVS work better.
>>
>>2) Does this suggest a bug in my PVS code (listed below).
>
>Your code looks alright, but why not try that through
>the entire full width search?
>
>>
>>3) Am I missing something else?
>>
>>Thanks in advance,
>>
>>
>>William
>>wbryant@ix.netcom.com
>>
>>Note: this code is only in the search_Root function not in the search function.
>>
>>//****** PVS Search
>>if (firstMove){ //following the pv so don't change anything
>> x= -search(-beta, -alpha, depth-1);
>> firstMove = false;
>>}
>>else{ //try a PVS search
>> x= -search(-alpha-1, -alpha, depth - 1);
>> if ((x>alpha) && (x<beta) && (!OutOfTime)) {
>> gPVSResearch ++; //research
>> x= -search(-beta,-alpha,depth-1);
>> }
>>}
>>//******
To the original poster: did these suggestions help?
Dave Gomboc
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