Author: Robert Hyatt
Date: 08:20:17 07/25/02
Go up one level in this thread
On July 25, 2002 at 09:07:48, Bas Hamstra wrote: >On July 25, 2002 at 00:14:19, Robert Hyatt wrote: > >>On July 24, 2002 at 22:00:04, Matthew McKnight wrote: >> >>>IID seems to give me a lower node count at some plies, but a higher one at >>>others. Is this just because IID doesn't give a huge speedup or does it mean >>>that I am implementing it incorrectly? >>> >>>Matt >> >> >>IID is not a huge thing. It mainly helps where you fail high but can't get >>a real score so that the next iteration, you end up with no hash moves for >>the PV search... IID will supply good moves. > >All you get is a reasonable move from a D-2 search. Why not store the original >hashmove in stead? Where would you get it from? I use the fact that there is no hash move for a PV node to trigger the IID search... >So when you normally store a UPPER score, in stead of saving >no move at all, you save the original hashmove? I don't see why IID would >provide a better move than that... Because at the _next_ ply in the tree, you have no move because it is a fail low position... Also, you assume that you already have a hash entry with a best move. But that is not a certainty... So if you don't have one, you can't "save it" with your trick. IID is simply a solution for this that is trivial to implement.... > >Best regards, >Bas.
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