Author: Uri Blass
Date: 00:02:17 03/07/06
Go up one level in this thread
On March 07, 2006 at 00:46:27, Dann Corbit wrote: >On March 07, 2006 at 00:41:55, Dann Corbit 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. >> >>Right. If you have divided off the eval components, you could binary search >>until you find the problem component. >> >>Now, we do not know for sure that it is an eval sign problem. However, the fact >>that the records are similar in pairs makes it very suspicious. > >I guess that when you have gotten your eval symmetrical, you will miss less than >ten problems on WAC. I think that you are wrong here. Stuart may have evaluation bugs but his main problem is the search. Uri
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