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Subject: is there a better correspondence analysis than silly fritz5's

Author: blass uri

Date: 08:07:13 06/29/98


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.


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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