Author: Georg v. Zimmermann
Date: 01:25:48 09/02/01
Go up one level in this thread
"Dull" ? :)
- You store the remaining depth. " ].nDepth >= depth " looks right. Check that
you also add the extensions to depth.
- If the hash type is a lower bound , this means that the true value can be as
low or lower. So you should check for a fail low, not "].Score >= beta". That is
wrong. Same for the upper bound.
- You are not adjusting the bounds, why ? That helps a lot.
- You should store the best move too.
If you still get wrong results, check whether the hasing itself is broken.
Create a second table with lots of #ifdef debug and different random number. See
if you get the same hits.
Good luck and have fun !
Georg
On September 01, 2001 at 19:34:40, Matthias Gemuh wrote:
>
> I am too dull to hash correctly. I have 2 depth variables in HyLogicChess:
>"depth" tells me how far I still have to go till Quiescence and "nPly" tells how
>far from Root in AlphaBeta Search.
> Which of them do I store in Hash Table? Which comparisons do I make when
>retrieving from table?
> Presently I store "depth" and retrieve as shown below, but retrieved values are
>clearly wrong.
>
> // Retrieving data from Hash
> if ((HashTable->HashEntry[ChessPosition->HaskKey].nChecksum ==
>ChessPosition->LockKey) && \
> (HashTable->HashEntry[ChessPosition->HaskKey].nDepth >= depth)) {
> switch (HashTable->HashEntry[ChessPosition->HaskKey].nScoreType) {
>
> case HashTable->HashEntry[ChessPosition->HaskKey].exact:
> return(HashTable->HashEntry[ChessPosition->HaskKey].Score);
>
> case HashTable->HashEntry[ChessPosition->HaskKey].lower_bound:
> if (HashTable->HashEntry[ChessPosition->HaskKey].Score >= beta)
>{
> return(HashTable->HashEntry[ChessPosition->HaskKey].Score);
> } else break;
>
> case HashTable->HashEntry[ChessPosition->HaskKey].upper_bound:
> if (HashTable->HashEntry[ChessPosition->HaskKey].Score <= alpha)
>{
> return(HashTable->HashEntry[ChessPosition->HaskKey].Score);
> } else break;
> }
> }
>
> Regards,
> Matthias.
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