Author: Stuart Cracraft
Date: 16:15:05 03/07/06
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On March 07, 2006 at 15:38:40, Robert Hyatt wrote: >On March 07, 2006 at 00:34:48, Stuart Cracraft wrote: > >>On March 07, 2006 at 00:31:45, Dann Corbit wrote: >> >>>On March 07, 2006 at 00:27:43, Stuart Cracraft wrote: >>>[snip] >>>>Very interesting indeed. A clever test. >>>> >>>>If one's results do not rotate approximately as described >>>>for the four positions and you say the evaluation is an >>>>issue, what kinds of evaluation issues have you seen that >>>>could explain it?!? >>> >>>The most common thing that I see is something that is good for white being >>>counted as positive for black also on the evaluation. Often, when we are >>>writing the eval, we are thinking from the perspective of white. And so if we >>>are not very careful, we may invert the sign of some evaluation component and >>>count something that is good for white as something that is good for black (or >>>vice versa, though the reverse is seen less often for some reason). >>> >>>There are, of course, many other possible causes besides that. >> >>A good point. I try to avoid that by always doing things from the >>side on move, almost always. There are a few in there however with >>respect to white and black specifically, but they are then folded >>together with the stm variable and stm^1 which translate to white/black >>or black/white depending on who's on move. I could try this: rerun >>your rotation test with successively less in the evaluation table >>until nothing but material and see what happens. >> >>Stuart > >Let me toss in that we are talking about apples and oranges at the moment. WAC >is not about evaluation very much. It is mostly about finding mates or >significant material wins, and there your evaluation isn't much help so long as >it knows how to add up the values of pieces... > >getting WAC solved quickly is really about tactics, extending the right things, >and trying to avoid extending the wrong things... But an asymmetric evaluation function could unbalance the search sufficiently to cause an issue, no?
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