Author: Christophe Theron
Date: 13:01:49 08/09/00
Go up one level in this thread
On August 09, 2000 at 05:41:22, Andrew Williams wrote:
>On August 08, 2000 at 15:56:04, Christophe Theron wrote:
>
>>On August 06, 2000 at 16:36:15, Vincent Diepeveen wrote:
>>
>>>Show me an MTD program that uses less nodes a ply as DIEP does.
>>>
>>>What diep is doing is very simple in search:
>>>
>>> PVS (starting with -infinite)
>>> check extensions
>>> checks in qsearch
>>> nullmove R=3
>>> no other crap. no pruning. Perhaps at WMCC i prune a bit,
>>> but that's because against computers playing is different.
>>>
>>> Yet i'm missing programs using less nodes a ply with MTD.
>>> I"m missing *any* deep searching program that uses MTD actually.
>>
>>
>>Anmon, a french chess program, uses MTD(f). It is a strong program.
>>
>>If you are not pruning in the tree, then MTD(f) should be better for you. I
>>don't use MTD(f) because I use the value of alpha and beta to prune in the tree,
>>and with MTD(f) this kind of pruning makes the search really unstable (you get a
>>fail-high, and when you re-search with a higher window you get a fail-low,
>>oops).
>>
>>
>>
>> Christophe
>
>
>What you can do in these cases is to use the external bounds instead of
>alpha and beta. By "external bounds" I mean the bounds that have been
>established in the mtdf() loop which is driving the alphab-beta search.
>
>Cheers
>
>Andrew
Thanks for the idea.
Christophe
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.