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Subject: PV length question

Author: Nagendra Singh Tomar

Date: 17:55:52 10/30/02


The question goes as.

Take the case of the first subtree search at the root, for say the 4th iterated
search (with depth 4). The prior depth=3 search would have made one PV. Now as
soon as I enter alphabeta, as part of the code I do board->pv_length[ply] = ply,
so for ply=0 (root) it become board->pv_length[0] = 0.
Now as part of move generation when I am in the GEN_PV phase, how do I know the
length of the PV so that I  generate a *correct* PV move.
The code goes something like

if(board->follow_pv==TRUE && ply<board->pv_length[0])
{
	generate PV move;

}
else
{
either we are not following the PV or the PV was short enough so that it never
reached till this ply.
}

Now if I have already made board->pv_length[0]=0 the second condition in the
above if check will always be false.
Note: This will change for later subtrees at the root as the first subtree
search will yield some PV.

But first subtree search is the most important.

One way I can think of is to use the hash as the PV will be there in the hash

Comments are welcome

regds
tomar



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