Author: Robert Hyatt
Date: 11:50:03 05/07/01
Go up one level in this thread
On May 07, 2001 at 13:10:19, Vincent Diepeveen wrote: >On May 07, 2001 at 06:46:42, David Blackman wrote: > >>On May 06, 2001 at 21:43:37, Robert Hyatt wrote: >> >>>On May 06, 2001 at 08:35:07, Vincent Diepeveen wrote: >>> >>>>On May 05, 2001 at 12:01:08, Dana Turnmire wrote: >>>> >>>>> Here is an interesting article found in a 1989 CCR article. >>>> >>>>Exactly the biggest misunderstanding in chessbooks is that 2 rooks >>>>are stronger as a queen. Even in most endgames a queen wins easily >>>>against 2 rooks. >>> >>>I wouldn't say in "most". I would say in "some". Two rooks can box up >>>a queen and make it impossible to win since the queen can't overpower the >>>two rooks without the help of the king... >> >>If it's just 2 rooks and some pawns against 1 queen and some pawns, i'd back the >>rooks usually to win. As long as there are not too many loose pawns, and the >>king safety is reasonable, the rooks can often win even when one pawn down. I >>used to think that the queen would beat or draw with the 2 rooks in an endgame, >>but now i've played a few of those endgames and seen a small amount of GM >>analysis, i've changed my mind. >> >>If there are more pieces on the board as well, it really depends on exactly what >>pieces, and on the kind of position. Knights seem to work very well with queens, >>and sometimes very well against rooks. Queens have much better mobility than >>rooks in many common positions, and can use this if there are several targets to >>attack and defend. But if the whole position is about controlling an open or >>half-open file and then using it, the rooks should win. >> >>I quite like the 1,4,4,6,12 basic piece values and i find they work well. They >>seem to get the right answer slightly more often than 1,3,3,5,9. In the case of >>queen vs 2 rooks, i think 1,3,3,5,9 is closer to the truth, but in most other >>cases 1,4,4,6,12 gets the same answer or is better. But either way can be made >>to work. You just need to get the right positional factors in there, and make >>sure they can add up to more than a pawn when they have to. > >And as you see the 1 4 4 6 12 is much closer to my piece values >as 1 3 3 5 9 is to my piece values... > >In 99.9% of all positions the computer sees 2 rooks for a queen the >queen side wins. Would you like to turn that into a wager? I can get someone to take the complete set of PGN games for everything crafty/scrappy has played on the various chess servers, extract just computer vs computer, then Q vs 2 rooks, and give you the results. It is actually pretty "even". But for your program, if you keep playing me and giving me two rooks and two pawns to get my queen, it is _not_ going to be very even, I can tell you that. You are going to lose. > >Just verbose print the positions! > >The GM positions are really exceptions! > >Harder to evaluate it is when Rook + light piece beats a queen. > >There is a position in bs2830 where this happens. The qxd3 position. >Some versions of DIEP find Qxd3 at 12 ply some at 13 ply. But it's >a very hard to find position!
This page took 0.01 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.