Author: Bernhard Bauer
Date: 04:33:07 09/29/00
Go up one level in this thread
On September 29, 2000 at 04:48:42, Dieter Buerssner wrote: >On September 29, 2000 at 03:08:25, Bernhard Bauer wrote: > >>On September 28, 2000 at 10:18:53, Dieter Buerssner wrote: >> >>>On September 28, 2000 at 04:26:54, Bernhard Bauer wrote: >>> >>>[much snipped] >>> >>>>My modification has also to do with null move, but I do another change. >>>>Instead of the original statement in search.c >>>>if (do_null && !tree->in_check[ply] && pieces >>>> && (pieces>5 || depth<421)) { >>>> >>>>I use the following statement >>>>if (do_null && !tree->in_check[ply] && pieces>0 && depth>60 && >>>> && (pieces>9 || depth>301) ) { >>> >>>This is interesting. The original Crafty code uses null move at the leaves of >>>the tree, when close to the endgame. Your code uses null move at at the front of >>>the tree. Has this shown to be better in test suites or in games? >>> >>>Also, you don't allow null moves at the last ply. Does this reach higher depth >>>with the same node count? > >Bernhard, I really read your source snippet different, then your description. > >>For many pieces (pieces>5) the original Crafty code will always use null move. > >Yes, this is like I read the source snippet of original Crafty. > >>I don't use null move for the first ply hoping to get a better move ordering. > >But wouldn't this mean to use "&& ply > 1" instead of and "depth > 60" > >>If only a few pieces remain I don't do null move for the first 5 plies. > >Again, wouldn't this mean to use "&& ply > 5" instead of "&& depht > 301" > >For your description I would use: > >if (do_null && !tree->in_check[ply] && pieces>0 > && ply>1 /* No null move at first ply */ > && (pieces>9 || ply>5) /* Little material: not for the first 5 plies */ > ) { > >Where is my misunderstanding? Nowhere, it's on my side. >Nevertheless, I think depth instead of ply seems superior, for example because >of hash table consistency. But then your ">" seems the wrong way around. >Remember that depth is the remaining depth, or have you changed the meaning of >depth? I would read "depth > 60" only one ply is remaining (which could make >sense, because there is not much you can cut off in the last ply). > >-- Dieter I will look at it later, no I have to leave immediately, my daughter has to go to the hospital. Kind regards Bernhard
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