Author: Aivaras Juzvikas
Date: 06:17:18 09/28/04
Go up one level in this thread
On September 28, 2004 at 07:06:18, Ed Schröder wrote:
>On September 28, 2004 at 01:16:30, Aivaras Juzvikas wrote:
>
>>On September 26, 2004 at 04:30:44, Ed Schröder wrote:
>>
>>>On September 26, 2004 at 00:51:17, Sergei S. Markoff wrote:
>>>
>>>>Some ideas on hash move extensions.
>>>>The idea was invented independently by Shpeer, Rybinkin ("Mirage") and me. In
>>>>most cases this is a good idea to extend TT moves to improve search stability.
>>>>But what scheme will be best for doing it?
>>>>
>>>>In ST the method is a little curious.
>>>>
>>>>TT_extesion_amount=INCPLY/RootDepth (in plies).
>>>>while(TT_extesion_amount*RootDepth<INCPLY) TT_extesion_amount++;
>>>>
>>>>Anyway it improves play of ST.
>>>>
>>>>I need your results to compare.
>>>
>>>Since Rebel 12 I am using this:
>>>
>>> in case of (2 consecutive best_move_from_hash_table
>>> && alpha < hash_table_score + margin)
>>> then { extend with one ply in case this situation happens x times }
>>>
>>>Notes:
>>>
>>>. margin is currently set to 1.00
>>>. x is currently set to 4, 8, 12, 16 etc.
>>>. alpha in Pro Deo's philosophy could be beta in yours.
>
>
>>i dont get this x thing, does the same position have to appear 4 times to get
>>extended?or only 4th 8th 12th appearance of this kind of situation gets
>>extended?
>
>The latter.
>
>The condition:
>
> 2 consecutive best_move_from_hash_table && alpha < hash_table_score + margin
>
>has to happen 4 times before you extend. When the counter says 8, 12, 16 etc.
>extend again. In case you are using fractional extensions just extend with 0.25
>for each successful condition.
>
>My best,
>
>Ed
thank you for your explanation.
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.