Author: Pat King
Date: 16:49:22 03/31/04
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On March 31, 2004 at 07:43:59, Bernd Nürnberger wrote: >(1)(I implemented null move, pv search, >mvv/lva, some history moves, transposition table, quiescence search ...) >Is this a bug or is this a normal behaviour? >For example, with 3 history moves (on initial position) i get: >[...] > 8. 0:01.12 993512 0.00 Nc3 Nf6 d4 d5 Nf3 Bf5 Ne5 Ne4 >... and with just one more history move (4): >[...] > 8. 0:01.28 1088694 0.00 e4 Nc6 Nf3 e5 d4 Nxd4 Nxd4 h6 When you say "3 history moves" and "4 history moves", I'm interpreting this as "I sort the first three or four quiet moves using the history table". I have two thoughts. a) I sort all quiet moves by the history table. It's probably a waste, but it's simpler. b) If I chose to limit my sorting (which quite probably is a good idea) I wouldn't make decisions based on the starting position. Very few (I would say "no", but I always get in trouble with absolutes) chess engines are any good at openings with a pre-made "book". The two lines you present are not unreasonable for a chess engine with no book. > >(2) >Another move ordering issue: my move ordering is as follows: > - hash move (if there's any) (hash table 1 mio. entries) > - captures (mmv/lva) > - some history moves (experementing with 3..5) > - rest unsorted >I get a first cut rate of 60 - 80 % percent. Is this too low or just >normal for this (still somewhat poor) move ordering? You mention that you've implemented null move. I believe the proper place to put this is before even your hash move. This could seriously impact your cut rate. If you're not counting null move cutoffs as 'cuts', then I think you may have an apple and orange type problem when you compare yourself to other engines. > >(3) >I searched the net forth to back and back to forth and cannot find any >good doc about SEE in move ordering. Does someone have a description and/or >links to descriptions, where I can read about this method? Sorry, can't help you there. > >Thanks in advance for your answers. > >Greetings, > Bernd Glad to shed what feeble light I have on your problems :) Pat
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