Author: Robert Hyatt
Date: 19:41:38 08/05/02
Go up one level in this thread
On August 05, 2002 at 19:07:58, Uri Blass wrote: >On August 05, 2002 at 17:50:27, Robert Hyatt wrote: > >>On August 05, 2002 at 12:15:32, J. Wesley Cleveland wrote: >> >>>On August 05, 2002 at 03:10:07, Jouni Uski wrote: >>> >>>>[D]8/4rk2/1p2r3/1Pp5/2Pp4/1K1P4/2PQ4/8 w - - >>>> >>>>Crafty's evalution after 14 ply +1,56. >>>> >>>>Jouni >>> >>>Crafty 18.15 static evaluation >>>material evaluation................. 1.60 >>>development......................... 0.00 >>>pawn evaluation..................... -0.04 >>>passed pawn evaluation.............. 0.00 >>>passed pawn race evaluation......... 0.00 >>>king safety evaluation.............. 0.00 >>>interactive piece evaluation........ -0.14 >>>total evaluation.................... 1.42 >>> >>> >>>Crafty 18.10 static evaluation >>>material evaluation................. 0.80 >>>development......................... 0.00 >>>pawn evaluation..................... -0.04 >>>passed pawn evaluation.............. 0.00 >>>passed pawn race evaluation......... 0.00 >>>king safety evaluation.............. 0.00 >>>interactive piece evaluation........ -0.14 >>>total evaluation.................... 0.62 >>> >>>Apparently Bob does believe that Q+P is much better than 2R >> >> >>I believe that in most positions, unless something really unusual is >>happening, that a queen is better than two rooks, when the computer has >>the queen. As a general rule, the queen can _always_ force a draw, >>because of the many checks it can give. And it often finds ways to pick >>up a pawn here and there. The exceptions occur when the rooks get doubled >>and can't be separated, but even then it is not a bad idea. >> >>I simply count a queen as equal to two rooks, period... And in 99.9% >>of the cases, that is at least correct... and often the queen is >>better when there is another piece on the board to help... > >You do not count it as equal but as better by 0.6 pawns based on the static >evaluation. > >I think that in most positions the queen is not better than >2 rooks. > >Based on experience of games of movei against opponents >there were even a case when movei could draw with 2 rooks against >queen and some pawns by perpetual check. > >I did not see the general rule that the queen can always draw >and I remember comp-comp games when movei with the queen lost >even against less material. > >Uri You are right. I folded this into the "bad trade" code a while back. IE a queen for a pair of rooks is good for the queen... a pair of pieces vs a rook is good for the pair of pieces, etc. The bad trade score is 160 which is what makes the difference here... It used to be 1/2 of the bad trade for q vs 2r, and I don't know when/where it got changed...
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