Author: blass uri
Date: 11:17:55 06/29/98
Go up one level in this thread
On June 29, 1998 at 13:55:30, Komputer Korner wrote: >On June 29, 1998 at 11:07:13, blass uri wrote: > >>Fritz5 has a function of correspondence analysis. >>with this function Fritz5 generates a detailed analysis tree for a position. >>I can decide how deep and broad the resulting tree should get and what >>moves should be included or excluded from the analysis. >> >>in order to use the fritz5 correspondence analysis I give fritz5 some numbers: >>1)time per move(it is time per node in the tree and it is not a good idea >>because I want to give the computer more time to analyze the nodes near the root >>because it is more important not to do a mistake in analysis near the root I >>think the possibility to choose time per ply 1,time per ply 2,... is a better >>idea) >> >>2)Branching:The branching factors for the 1st,2nd and 3rd moves define >>how many alternative moves are given in the first ply,second ply and third ply >> >>3)Length of variation:This sets the length of analysed variations >> >>4)Evaluation window:This value ,given in 100ths of pawns,determine when >>Fritz will discard a variation. If you set the value to 80, for instance, >>then moves which are 0.8 pawns worse than the best move will not be investigated >>any further-even if the branching factor would allow it. >> >>The main problem with the tree fritz5 generates is the fact fritz5 >>analyses illogical lines >> >>for example suppose the branching factors are 2 for the 1st ply 2 for the >>second ply and 1 for the third ply >>and the length of variation is 3 >>and the time number is 60 seconds per move >> >>Fritz5 can do the following tree >>it is only an example(fritz5 did not generate this tree but generates trees >>with the same mistake) >> >>line 1:1.e4 e5 Nf3 0.1 pawns for white >>line 2:1.e4 c5 Nf3 0.2 pawns for white >>line 3:1.d4 Nf6 c4 0.08 pawns for white >>line 4:1.d4 d5 2.Nf3 0.04 pawns for white. >> >>near 1 minute for finding 1.e4 and 1.d4 the two best moves. >>near 1 minute for finding 1...e5 and 1...c5(2 best replies to 1.e4) >>near 1 minute for finding 1...Nf6 and 1...d5(2 best replies to 1.d4) >>near 4 minute for finding the third ply in lines 1,2,3,4(1 minute for a line) >> >>I do not need the last line to understand 1.e4 is better than 1.d4 >>because I know the value of 1.e4 is 0.1 pawns for white >>and I know the value of 1.d4 is at most 0.08 pawns for white but fritz5 >>analyse the position after 1...d5 and waste time about it. >> >>fritz5 does not use the alpha beta for the tree it shows me and I do not >>understand why. > >When you are in k variation mode which is essentially what the correspondence >feature is, alpha beta only applies within each variation, not across >variations. I think it should be simple to use the alpha beta across variations. fritz5 uses the alpha beta for a very large tree I cannot see and it should be simple to use the alpha beta for the tree I see when the computer computes near 1 node per minute in this tree instead of 200000 nodes per second. Uri >> >> >>another problem with the tree is that I can tell Fritz to analyze >>more than 1 line only in the first 3 plies >>I believe the computer can do mistakes in evaluating the best move but not many >>mistakes so if for example the length of variation is 6 then I want the >>possibility to tell the computer to use 2 branching factors for the first >>time the computer do a mistake and the second time the computer do a mistake >>instead of the first,second and third ply. >> >>another problem is that I see the evaluation function only at the leaves of the >>tree. I prefer to see the evaluation function after every move because if it >>was changed drastically I can suspect the last move was a mistake. >> >>Uri
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