Author: José Carlos
Date: 07:48:42 09/08/02
Go up one level in this thread
On September 08, 2002 at 10:23:31, Brian Richardson wrote: >On September 08, 2002 at 08:45:12, Robert Hyatt wrote: >snipped >>I am not sure what you mean. But the answer is to look at your search code, >>and pick a position and ply where you are going to probe the hash table when >>you enter search. remember that number. Now assume you don't get a hit, so >>do a normal search, and look at the two ways to get out of search: (1) you >>get a fail high; (2) you don't. Make _sure_ that at each of those two >>places, you store the _same_ depth you used when you probed the table at the >>start of this search. If not, you have a problem... > >Bob: Could you try to explain why this might be a problem. The scenario is: >upon entering the search routine at a new (deeper) ply n, the hash table is >probed. If the search continues, extensions (e) can get added to the depth. >Moves get searched and then the resulting bound or exact value is stored with a >deeper depth n+e than was originally probed. > >Ok, the question is, next time this position is probed, even if it is at the >same original (n, or lower depth), wouldn't the "deeper" n+e hash depth search >value still provide a valid result? Or, deeper is always better, right? > >Thanks. In your example, when you enter that same node in the next iteration with (very probably) depth+1, you might cut with the hash hit, which isn't correct. José C.
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.