Author: leonid
Date: 04:20:29 10/04/99
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On October 04, 1999 at 03:50:52, Ed Schröder wrote: >>Subject: Re: Raw speed of Rebel 10 higher that Hiacrs 7.32 ? > >>>The keyword to understand the topic = extensions. >>> >>>Chess programs do use all kind of extensions and all chess programs do >>>it another way. Some programs do not emphasize on extensions other >>>programs heavily use extensions. >>> >>>A common example of an extension is to extend the ply-depth with "1" in >>>case the king is in check. Thus instead of searching 6 ply the remaining >>>tree is searched for 7 plies. If there is another king-in-check case found >>>the search is extended to 8 plies and so on. >>> >>>So you see a 6-ply search isn't a 6-ply search as a lot of variations in the >>>tree are searched deeper. >>> >>>Some program will extend king-in-check cases even more. On some types >>>of checking moves Rebel will extend 2 plies. Other programs have their >>>own ways of doing things. The end result is that you can't compare programs >>>based on ply-depth. >>> >>>Ed >> >>This explanation puzzle me. My impression was that "brute force" in given >>number of plys deep should include nothing but number of plys asked. Every >>other extra ply for every other extra reason is inappropriate. I can only >>understand that in all games logic should go some extra plys (or extention) >>if it like to do this but not when "brute force" is asked. To see >>some extra ply in "brute force" search (even partially) is pious fraud. It >>sound >>like find the mate in 5 moves but announce it as mate in four. >>Brute force search in certain number of plys signify for me search for all >>the possiblities that existe for given position but going only the number >>of plys said to be performed. If "brute force" is what I see it to be, it says >>more that every other aspect of the game about the general capability of the >>chess game itself. >> >>Leonid. > >It is much worse than you think. > >5n2/B3K3/2p2Np1/4k3/7P/3bN1P1/2Prn1P1/1q6 w - - bm e3g4; > >Try this position. Rebel will find the mate-in-30 on the second ply. Nowadays >programs are not going to do a 60 ply search. They extend such cases. > >Ed This very interesting what you said. Would never expect that some game will go to search the mate in 60 ply. Even doing this through the "quick logic" it can take a long time. I found that it is practical to search the mate only 12 ply deep but even this my logic will never do while searching the positional move. If not it will stay there for ever. For sure your logic is as smart, as quick and different as well. If somehow I speak with the guy that did the Rebel, MY CONGRATULATION!!! I actually liked very much your game in every aspect but the most for its "direct talking". Even there is said that it see up to 100 moves per ply. Who ever say this? And do you have some dedicated part for searching the mate, or everything goes in one logic? Hyatt have said that in game we have one logic to do everything, only parameters are different. I am still not sure. There are so many surprises. Leonid.
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