Author: Tony Werten
Date: 12:45:28 08/24/01
Go up one level in this thread
On August 24, 2001 at 15:18:04, Carmelo Calzerano wrote: >On August 24, 2001 at 13:47:12, Tony Werten wrote: > >>On August 24, 2001 at 09:19:23, Robert Hyatt wrote: >> >>>On August 24, 2001 at 04:31:27, Tony Werten wrote: >>> >>>>Hi all. >>>> >>>>I like to know if there are some solutions for this problem. >>>> >>>>My program searches for 4 minutes, gets to 14 ply (or whatever), makes a move, >>>>takes a pondermove and starts pondering. >>>> >>>>Now the first 12 ply are taken from the hashtable (<1 sec ) but it starts an >>>>(almost) uninformed 13 ply search from which it is never going to return in the >>>>allocated time, so it's just taking the best move it had from the previous >>>>search, which is costing me plydepth. (and games ) >>>> >>>>Any ideas, sugestions ? >>>> >>>>cheers, >>>> >>>>Tony >>> >>> >>> >>>Internal iterative deepening can help here. The problem is that if your >>>first move comes from the hash table with a good score (typical on pondering) >>>then you reach depth N with a PV that has only that move in it. (there are >>>things you can try to do, such as extending the PV in such cases by probing >>>for the second position, etc when you back up the PV). IID works by doing >>>shallow searches to find good moves at PV-type positions where you have no PV >>>move. If you don't do something like this, you reach critical positions with >>>no real hope of having the best move searched first, which makes the tree >>>explode in a bad way... >> >>I use IID but that isn't the problem. I get the PV from hashtable and do get a >>full length PV. So at ply 1 I get a 12 ply PV, as on ply 2,3 etc. All within a >>second. Then I reach ply 13 and get into problems. > >Here I don't understand: don't you get a 12 ply PV (better, a PV which comes >from a 12 ply search) when searching at depth 1, 2, ... 12? If so, you should >have the same PV when searching at depth = 13, which is all what you need... >What am I missing here? Having only a 12ply pv in a 13 ply search isn't really going to help you if you want to finish the search in a reasonable time. Tony > >Regards, >Carmelo
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