Author: José Carlos
Date: 08:22:18 06/04/02
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On June 04, 2002 at 10:49:00, Vincent Diepeveen wrote: >On June 04, 2002 at 08:54:57, José Carlos wrote: > >What i read in Dann's words is he is more believing in search >rather than the knowledge. If that's the case then i think he is >wrong. > >I do not see how to easily improve search either. > >Let's compare diep 1998 with diep 2002. > >Of course when takling about eval we are quickly finished. It's >way bigger now and way better. Let's just compare the SEARCH now. > >DIEP 2002: 8 probes hashtable, nullmove R=3 always, 2 killermoves, >complex move ordering but not that much changed last years, >some complex extensions but those >do not contribute much to the game, at most solve testsets a bit >sooner. quiescencesearch is pretty complex but compared to 1998 >very simple as i do way more there now. > >Now DIEP 1998, this is a very complex search. First of all i did >all kind of efforts to not get too undeep. It was getting not enough >depth at tournament level to even see basic tactics which i see. > >So i did all kind of difficult forward pruning. Also weird things >like special killertables were used. Special information was gathered >in order to search less last few plies and qsearch was way more >limited. Nearly no check was extended in the main search, because >this was to expensive. Hardly any extension was done there. > >Of course it was not a parallel engine, but that's about only thing >which has become more complex in search, though it in fact is still the >same type of search. > >In short my search has become much simpler, especially when talking >about quiescencesearch. I'm not blinking with my eyes now to have >a bigger overhead there! Interesting, thanks for sharing. So, in a sense, you've improved your search by making it simpler. If I get your point, there's a tactical-safe zone which you tried to reach in the past by complex search techniques. Now you find that current hardware allows you to get to the safe zone without prunning a lot, so you preffer to simplify your search in order not to prune something important. Just out of couriosity, how many extra plies do you think your old 1998 search would get in today's hardware? If you put your current eval into 1998 DIEP, do those extra plies really not compensate for the loss of some variations? And yet another question, how many extra plies do you think a complex search would need to get, compared to your simple search, in order to outperform it tactically? [Note: when I say 'ply' I mean DIEP's ply, which is guess is worth ~HIARCS ply]. José C.
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