Author: James T. Walker
Date: 14:52:03 04/02/99
Go up one level in this thread
On April 02, 1999 at 10:51:27, José de Jesús García Ruvalcaba wrote: >On April 01, 1999 at 08:19:57, James T. Walker wrote: > >>On April 01, 1999 at 06:24:43, Sylvain Renard wrote: >> >>>On March 31, 1999 at 18:01:28, James T. Walker wrote: >>> >>>>Hello again Sylvain, >>>>Obviously you know more about these things than I do. As I said in an earlier >>>>post I'm not a programmer or even a good chess player. But I still keep coming >>>>back to the CD ROM as the problem. I don't know if Fritz uses Ken Thompsons >>>>database or what. Fritz does not do a normal "search" on this move. Fritz >>>>seems to read the CD ROM and then make the wrong move. The info which shows up >>>>in the move window indicates Fritz has incorrect information about the value of >>>>the moves in the move list. Where do these values come from? All moves have a >>>>score of draw so it does not matter which one it plays. Evidently the first >>>>move "generated" or looked at is f8=B and it plays that move. >>> Hello again, >>>when reading the databases, if the position reached is not found, Fritz has to >>>assume it is a draw. What else could it do? I think they did not think >>>it was useful to include all the files resulting from an underpromotion. >>> >>> >>>>Fritz 5.32 with >>>>the Fritz 5.32 CD ROM does not play that move. It correctly has the score as >>>>(8) 1.f8=R. Why does Fritz play the move correctly with the new CD ROM but >>>>incorrectly with the old CD ROM? >>> ?? I must have the old CD ROM because my Fritz 5.32 shows 0 as the score >>>after f8=R. Could you look at the files in the root directory of your CD >>>and tell me if the file Rr_r.g is present on your CD? Thank you. >>> >>>> Fritz does not go back to a regular search >>>>routine untill after the f8=B move. >>> This is a bug on my Fritz5.32 because it has the file Rb_r.g on the CD >>>and does not use it when you enter a corresponding position. >>> >>> Best regards, >>> Sylvain >> >>Hello again Sylvain, >>Have you updated to the "March SP1" at Chessbase/Germany? Anyway here is a list >>of all endgame files on my CD ROM. >>Pq_q.g >>Pr_r.g >>Q_pr.g >>Qr_q.g >>Qr_r.g >>Rb_r.g >>Rn_r.g >>So the Rr_r.g is not on the endgame CD. As I have said I don't see where this >>is necessary since when you get to this position any program can win from there. >>Since Fritz only searches the CD at the root you would have to already be into >>this endgame before Fritz would search the CD and at that point it is not >>necessary. Fritz must make the proper decision of promotion before exiting the >>Pr_r.g file. It is still a KRP vs KR untill after the promotion in my opinion >>and this file must have the correct info for this to work. >>Jim Walker > > To make the right choice with a pawn on the seventh rank (which can promote to >four different pieces), the promotion files are required. That is because >"probing at the root" really means probing after a one-ply full width search. >José. Hello Jose, Thanks for the info. I understand what you are saying but I don't understand why "the promotion files are required". I know that would make the promotion easy but why couldn't you just include the promotions in the database you are using? I see no reason why you can't include these promotions since you are not planning on having the next set of tablebases. Wouldn't a little planning allow this? Or is it impossible to add these to the end after the tablebases are generated? This begs the question- How do you decide which tablebase to go to when there are 4 possibilities? Do you probe all 4 tablebases before making the promotion? If that's true then it seems like putting the promotion in the tablebase already in use is more sensible. Jim Walker
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