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Subject: Re: how programs analyes games (front-back) or (back-front) which is better

Author: Mike S.

Date: 13:02:38 11/21/00

Go up one level in this thread


On November 21, 2000 at 14:48:25, Robert Hyatt wrote:

>On November 21, 2000 at 14:32:51, ERIQ wrote:
>
>>or is either better ?? your thoughts.
>>
>>I was thinking about buying yet another program for analyses of games.
>>(...)
>
>I don't like back to front.  It requires that stuff from the end of the
>game be back-filled through the hash table.  Here are the two arguments:
>
>1.  back to front is better... because you can use stuff happening at the end
>of the game to influence scores and moves earlier in the game.
>
>2.  front to back is better because it gives a true reflection of what the
>computer would have seen had _it_ been playing that game directly.
>
>(...)

From my experience with Hiarcs 7.32, I can tell that 1.back to front
impressively enhances the analysis, especially if you step through certain
variations back and forth manually (I think H7.32 was the first one with the
backward feature of this kind; Fritz 5.32 had it with the special function only
AFAIK). For example, the program kind of carries mates upwards through the game,
which results in a mate announcement much earlier than possible in a front to
back analysis, given the same time. Of course, the same logic applies to any
kind of continuation, as long a the point of a move or idea is contained in the
notation (!) the program calculates on.

Therefore, it's clear to me that back to front is not useful for testing the
program (instead of the game's moves). But testing requires to know the correct,
or best, answers already. On the other hand, I can imagine that for the analysis
of test games, it is good to begin with 1. back to front as a first step to find
the "peak situations" of the game, which are the important positions to start
the tests.

But for the analysis, if the point has NOT been played or included in a
variation ahead, the "normal" search which is applied anyway for each single
move (too) is utilized, i.e. by the Fritz GUI's analysis feature. Btw. it
produces variations during this too.

In short words, my recommendations:

Game analysis:   back-front
Program testing: front-back


Regards,
M.Scheidl



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