Author: Robert Hyatt
Date: 20:47:55 08/14/02
Go up one level in this thread
On August 14, 2002 at 19:30:51, martin fierz wrote: >On August 14, 2002 at 08:16:30, Vincent Diepeveen wrote: > >>On August 14, 2002 at 05:37:32, Bas Hamstra wrote: >> >>>On August 13, 2002 at 15:18:04, Vincent Diepeveen wrote: >>> >>>>On August 13, 2002 at 07:23:38, Uri Blass wrote: >>>> >>>>>My definition for a sacrifice or blunder >>>>>is a move that lose material based on >>>>>the depth that programs can see. >>>>> >>>>>The definition of losing material is based on >>>>>the material values 1,3,3,5,9. >>>> >>>>with all respect but your table is outdated in advance. >>>> >>>> a) 2 rooks are weaker than a queen in 99.9% of all cases >>>> the computer sees 2 rooks for a queen >>> >>>With all the respect master, but this is an ancient point of view that does not >>>hold for computerchess at all. Two rooks can capture an isolated pawn and one >>>sole queen cannot prevent that. I say it's about even. Try to play an endgame >>>with a queen versus 2 rooks, with Diep against Tiger or Gandalf. >> >>KQ KRR is an endgame database. >obviously, he was talking about KQ KRR and pawns on the board. > >>In the average position, and as we know the vaste majority of all 10^43 >>positions which chess has is middlegame, up to the late endgame, the >>queen is provable better as it is much better in capturing the >>random pieces that are laid down at the board. >> >>Queen = 11.5 >>rook = 5.0 >> >>in the *random* case. > >which is totally irrelevant. since in the majority of all real chess positions, >pieces are not randomly laid down on the board for the queen to capture. your >eval of queen = 11.5 and rook = 5.0 is completely wrong for any normal position. >the queen is typically weaker than two rooks, if they are not badly >miscoordinated. > >aloha > martin I evaluate this a bit differently. 1. KQ vs KRR. The queen is _just_ as good as the two rooks. 2. Add a pawn or more and the same thing holds. The queen is more dangerous checking around and forking the king and a rook or pawn. 3. The exceptions I see are king queen and _isolated pawns_ vs king and rooks. The isolated pawns simply can not move without the king _and_ queen to help them along. But then the two rooks can connect along a rank and make it nearly impossible for the pawns to reach that rank, and if the pawns are not far advanced, they can pile up and pick off the weak pawns one by one. In considering all the above, in general the queen is no weaker than the two rooks. Again, in the general case. The queen _may_ win here and there. The two rooks rarely win. Most end in a draw, in fact, because the queen has so many perpetual options. As a result, I prefer to see Crafty with the queen. It can generally draw if it needs to, and has chances with the check-check-check-fork type traps...
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