Author: leonid
Date: 06:36:39 11/19/01
Go up one level in this thread
>Small depths do not gain from the hash table. From Chest:
>
> static Bool
>job_dep_wants_acm( int jt, int depth )
>{
> /*
> * For a repeated position we need at least 4 plies (two full moves).
> * Since we ask at the start of "do_ana()", where the attacker is
> * to move, an additional preply turns out to make no difference.
> */
> switch( jt ) {
> default:
> case JT_normal:
> case JT_stalemate:
> case JT_selfmate:
> case JT_selfstalemate:
> break; /* take default rule below */
> case JT_helpmate:
> case JT_helpstalemate:
> return depth >= 3; /* since storing jobs of depth >= 1 */
> }
> return depth >= 4; /* since storing jobs of depth >= 2 */
>}
It is true what you have said. To even use hash you must have certain depth to
make it fonctional. But I have seen with Rebel even more simple reason why hash
is not effective with less that 5 moves. It look like that program do initially
certain work with hard disk in order to initialize something. If it is really
so, it could be that this initialization work is just too big to be payed back
at shallow depth.
Heiner, I wanted to ask you something already few times but manage to forget it
all the time. Are you able to use successfully data when making mate search for
contantly growing depth? I think that this is called "iterative search". If, for
instance, search at depth 3 will make quicker search for you at depth 4?
In my program I was not able to reuse data. At each new depth all variables are
initiated. When I tried to use search data, it was never successful. I do make
this question thinking that maybe even here I can look for some extra speed that
until now eluded me.
Cheers,
Leonid.
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