Author: Uri Blass
Date: 03:58:06 11/05/02
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On November 05, 2002 at 06:40:30, Sune Fischer wrote: > >>My first iteration is ply 1. >>Why do you use ply 2 as the first iteration? > >The root move is done seperately from the search, so 2 plies is the least I can >do. I also do it seperately but I still can do ply 1. In the first ply my alphabeta function usually calls the qsearch(except cases when there are extensions) I am considering doing another stage to prepare for qsearch, but may be that >is getting over technical. > >>I can also see cases when pawns are trapped in the 7th rank. >> >>I agree that pawns in the 7th should evaluated as more than regular pawn but I >>think that bonus of more than one pawn is more than enough. >> >>There are cases when it helps but the average result is negative. > >I know, but I had to make a quick fix because it was simply getting killed for >under evaluating advanced pawns. A more precise evaluation on the advanced pawns >should be done, things like - does the opponent dominate the promoting >square(s), can he block the pawn from advancing further, is his king within >reach etc.. Important to know for the evaluation, but also a very dynamic score >upwards of the queen value might not be a bad idea. I agree that a better idea is to evaluate these factors(something that movei does not do today) I also did a fix of it because it was too small but fixing it too much is a mistake. I usually look for the minimal change to avoid the mistake and not for more than it and even with a constant bonus of 0.7 pawns that is in the latest movei I saw cases when it evaluated pawn in the 7th rank as too much. I care about games and not about test positions and I do not want it to push pawns to the 7th rank when the pawn may be trapped. I think that without more knowledge 1.7 pawn is a good compromise(I am not sure about the best value but more than 2 pawns seems to me too much). Uri
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