Author: Carmelo Calzerano
Date: 12:18:04 08/24/01
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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? Regards, Carmelo
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