Author: José Carlos
Date: 23:28:30 10/13/03
Go up one level in this thread
On October 13, 2003 at 15:02:05, Robert Hyatt wrote: >On October 13, 2003 at 12:57:04, José Carlos wrote: > >>On October 13, 2003 at 12:03:32, Vincent Diepeveen wrote: >> >>>On October 13, 2003 at 11:31:11, Robert Hyatt wrote: >>> >>>>On October 13, 2003 at 09:29:47, Vincent Diepeveen wrote: >>>> >>>> >>>>> >>>>>there are very big differences. >>>>> >>>>> >>>> >>>>There isn't a big difference if you are only talking about the q-search. >>>> >>>>If you do a check, you have to get out and that extends. If you extend >>>>on the check you don't extend when you get out and that extends. >>>> >>>>It is different in the normal part of the search, because if you extend on >>>>a check you increase depth by one now. You might reach the q-search if you >>>>wait to extend when you escape check. but in the q-search I don't see how it >>>>is a "big difference". >>> >>>You don't have to apologize for not knowing basic tree math, you're excused. >>>Had seen already in crafty code that it was done wrong there. >>> >>>Yet i had already posted years ago at CCC that if you extend when being checked, >>>that this is better than when giving the check. >>> >>>What delivers more cutoffs for the hashtable: >>> >>>A) >>>Re5+ (5 ply remaining) >>>Kf7 (5 ply remaining) >>>Rxa5 (4 ply remaining) >>> >>>B) >>>Re5+ (5 ply remaining) >>>Kf7 (4 ply remaining) >>>Rxa5 (4 ply remaining) >>> >>>If you can answer that question then you'll know the answer to the basic tree >>>searching question. >>> >>>Best regards, >>>Vincent >> >> >> Do you cutoff in moves or in positions? >> If you cutoff in positions, then you have: >> >>Extend check: >> >>A -Re5+-> B -Kf7-> C -Rxa5-> D >>5 5 4 3 (depth remaining) >> >> >>Extend out-of-check: >> >>A -Re5+-> B -Kf7-> C -Rxa5-> D >>5 4 4 3 (depth remaining) >> >> So the only difference is position B. In the first case you store depth 5 in >>the hash table, in the sencond case, 4. >> In principle it seems that extending checks would give more cutoffs due to >>hash table, but to get to position B you need a checking move, which would >>extend (increase remaining depth) in the first case, and not extend in the >>second. >> The result seems to be that both will work the same, except for leaf nodes, as >>Bob pointed. >> >> José C. > > >Don't fall into his trap. In the q-search, which I _explicitly_ said I was >talking about exclusively, there is no "depth remaining" to extend. His >comments are, as always, nonsensical. > >If we were talking about the basic search, then things are a bit different. >But I do it my way there for a reason. It guarantees that I _never_ reach >the q-search when the side-to-move's king is in check. > >But we weren't talking about that case in what I wrote and where Vincent >responded with a completely random comment. But I think he's also wrong for the main search, because for interior nodes, assuming as Omid pointed, a correct use of the hash table, the result must be exaclty the same. I expect Vincent to understand it, but not to admit he was wrong for so many years. José C.
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