Author: fca
Date: 07:33:01 08/10/98
Go up one level in this thread
On August 10, 1998 at 08:36:36, Christophe Theron wrote: >On August 10, 1998 at 00:02:15, fca wrote: > >>On August 09, 1998 at 20:13:56, Christophe Theron wrote: >> >>>On August 09, 1998 at 19:18:52, Robert Hyatt wrote: >>> >>>>On August 09, 1998 at 10:22:31, Christophe Theron wrote: >>>> >>>>>Thorsten talked about this, but maybe it applied to older versions of Lang's >>>>>programs. Nobody has given evidence that Genius selects differently its moves >>>>>than the opponent's, except in the very end of the lines. >>>>actually, several posted a few positions where Genius appeared to show an >>>>asymmetric search. It couldn't find the key move with a very deep search, >>>>yet if you play the key move and let it play the other side, it would find that >>>>it was lost very quickly. Which lends credibility to the idea that it looks >>>>at everything for the opponent, but prunes (forward prunes) its own moves >>>>quite a bit in the right circumstances... >>> >>> >>>I remember Thorsten said he would post some of these positions, but he didn't do >>>it, or I just missed his posts. >>> >>>I would be interested to see such positions. If somebody has found such >>>examples, would he be kind enough to repost them, please? >> >>I think there is a misunderstanding here. By Bob, maybe by Thorsten and others >>too. >>Genius is highly "modularised." Depending on perceived game phase, a different >>evaluation module (code segment - not just a couple of variables) is used. >>But... >>Which module to use is only set at root level. Within, the same module stays >>used. >>So say the root move being considered would, if made, change perceived game >>phase (not necessarily a capture, but usually so, I believe). While it is >>examined - even to 32 ply depth - the lens used will still be for module x. >>However deep the search. >> >>Now the move is chosen. So module y is now used. Alas, the evaluation is >>significantly changed - i.e. Genius now "sees it" truly. >> >>This is the heart of the problem that is misdiagnosed as asymmetry (without >>denying or confirming that such asymmetry exists :-) ). >> >>Kind regards >> >>fca > > >What you are describing is sometimes called the "blemish effect", and is well >known by most of us, including Bob, Thorsten and me of course. > >Genius has indeed some trouble evaluating a queen exchange for example. It's not >the only one in this case! Fritz5 seems to be a little bit improved in this >regard. > >When Thorsten coined the idea that Genius was assymetrical, I think he wasn't >confused by the blemish effect, and really meant that some agressive pruning was >done for one side only. > >The problem is that it is not easy to show. In a normal game, Genius analyzes >only its own moves. To discover the assymetry stuff you have to replay the whole >game, ask Genius to analyze both sides, and watch carefully any score swing. Yes. >Did somebody try that? Yes. I remind you I said in the preceding post: "without denying or confirming that such asymmetry exists" >As you seem to have a close connection with Richard, maybe you could ask him? :-) >But I guess I already know the answer: > answer = "" ; Answer actually is: CbEFhPyMS/2x8P8Sqo/jCzbSKcoyxWIM8PgqoD45RiNtKAzTzYD+/gei41ytSw/V 8RNbStX2xCrKJTlEGpe3UGbN4HKXVGDcTiNNKN/sKFpnvuwghhPI+HKAj8xB+joQ em0jM6GnCahRMGGJuJHWPN5JXLlPBLizzG2szlS5hx6SwGlhEJKSXaahK/+fANR3 K9i2cUJ0J6uXWVKPi3vHYBNx9oXaNtTLKK4CusGWcWbTZHYAri8tHudzV0ssyNc7 ANghB2VlrNKgZL8bAfOoD9pbD/AsJEwr99gR84ZiVM+lpBBzPNQbD30S/Ihmq5AV yc/fuotEfz8lWDoQY+lDpp88aPkbZxwt/hQIQ+uTf14smekjMa+P+0B1uXls But PGP key might be hard to find. :-) :-)) > Christophe :) Kind regards fca PS: Disassembling Genius would be instructive.... :-)))
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