Author: Robert Hyatt
Date: 06:34:46 02/24/98
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On February 24, 1998 at 06:24:04, Thorsten Czub wrote: >I thought fritz/nimzo vs. Rebel are an exception ! :-) >From my point of view there is NO pattern in the games - rebel8/9 looked >pretty outsearched ! And this means you don't get a typical pattern like >: >your king safety is too weak or enemy handles the pawns better or >whatever. > >Concerning the hash-tables I have to admit that fritz seems to handle >them different than other programs. fritz is very hash-table sensitive. >I don't think other programs behave the same way concerning hash like >fritz does. >Maybe Frans has programmed something different. >You can test yourself by reducing hash-tables in fritz5 and find out >THAT fritz is very sensible if you reduce the hash. > >no - the fast searchers have - for the first time in the history of >computerchess and ssdf-list, overtaken the knowledged based programs. >THATS the big surprise. you haven't been around long enough to say that. Can you spell Chess 4.x? they went from smart/selective to dumb/fast, and set the world on fire. Cray Blitz went from smart/selective to dumb/fast (at first) and went way up in speed, with a real rating of 2258 (USCF) in 1980. There's nothing new here at all. You simply find that there are two approaches. Fast means simple, which translates into easy debugging issues. Smart means complex, which translates into complex debugging issues. Although I don't agree that Rebel is a slow/smart program when it is faster than Crafty on equal hardware... >When we played in Paderborn we had many discussions concerning >OUTSEARCHING the opponent, due to the fact that ChessTiger and Nimzo98 >behaved like this. >Nimzo98 outputs did not show this but the games looked like this. Any >opponent of ChessTiger was starring with wide eyes on it's search >depths. Vincent ran arround and told anybody stories about SCHACH3.0. In >the game vs. clever+smart e.g. this was very easy to see. Clever got a >fail-high, and after 2 minutes a bad fail-low following Tigers moves. >Nimzo98 attacked Tiger like hell, the game turned arround several times. >But - in the end was also a draw. > >Maybe Fritz5 with big hash can OUTSEARCH the others, meanwhile fritz5 >with LESS hash cannot do this. >I have tried it out myself by putting enough ram into my machine. The >changes were drastic. WHY ? If I were Frans I'd be concerned that my hash-replacement algorithm was *not* doing its job. IE in normal positions, we only get 10-20% hash hits anyway. So there's no reason to go in the dumper when the table fills up, *unless* the hash replacement algorithm is not working well, or is too simple to work well.. >WHat is Frans doing with the hash-tables ?Or better - what is he doing >different that increasing of hash lets the playing-strength increase >linear ! >One main thing of course is the big number of HITS fritz gets with >computing almost 200K NPS. but it isn't that big. IE Cray Blitz, searching 5-10M nodes per second reports 20-30% hash hits (max) in the opening/middlegame. It does go *way* up in endings of course...
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