The queen issue won't be resolved any soon as also between programs there is a lot of struggle. I feel there is not 1 truth there. Just that in most random positions the queen picks up sooner material.lkaufman wrote:I disagree with your statement that in general the queen is stronger than two rooks, definitely not weaker. All of my research, both in database stats and in optimizing the piece values for both Rybka and Doch, indicates that the queen is nearly equal to two rooks, but is worth a bit less (maybe a quarter pawn or so), not a bit more. Looking at the values assigned by different programs to the pieces is only useful if you know that they are well "centered", which is not always the case. I know it is not at all the case in Stockfish, the pawn is worth more in that program than its stated value.
As of your database research, referring to that is rather pathetic.
Your research looks more of a case of writing over research from others rather than any serious research.
It just quotes values similar to some GM's in the past long before computer age was there. I assume your database was a book quoting values from Max Euwe and Fischer.
Obviously not even 1 database research would show the values you figure out.
For a starter as you can see from tuning of stockfish, if you use automatic tools you don't find nice fixed rounded values, but total broken values.
Your values are according to wiki
3¼ 3¼ 5 9¾ Kaufman 1999 Add ½ point for the bishop pair[7] (Kaufman 1999)
That's not even close to rybka by the way.
In rybka actually the material only table gives 2 rooks against queen +0.94 for the ROOKS and that goes up, so far away from the 0.25 pawn you 'advised'.
In short you had NOTHING to do with the parameter tuning which is NCSA domain, and you are far away from those guys. Thank you.
It gives a bonus of +0.9 to +1.2 for a bishop pair
A knight is 0.6 stronger than a bishop in case of not a bishop pair running back to +0.36 of a knight being stronger. So they are not 'equal strong' at all.
Even if you had done your database research well, you can see that also Kasparov played like that (regardless of what he said).
That are the default material values in Rybka.
Please note also the rybka values are not exact rounded values to a quarter of a pawn, they are broken values of course and they don't even claim to have done database research.
As you see every tunings experiment carried out reach total other values.
My mainpoint is:
If you 'inject' your piece values into a chessprogram it plays litterally hundreds of elo's weaker. Yes even a chessprogram from the 90s.
You can easily set values of material for really about any commercial program. It requires 6 mouse clicks or something and then with 1 push at the button it can play games and you get results.
Even that obviously your 'research' didn't try. So it is total crap research.
If you would, you would have concluded quite some other values of course.
In 1999 a very easy manner would have been using the chessprogram nimzo1998 for that, to give some trivial example. By then released for years.
Note in 1999 the values of Diep were 3.6 for a piece and most programs had similar values like that. So not close to 3.25 either.
3.5 was the standard back then with Chrilly's 1998 values publicly visible in his chessprogram where with Che even you could program.
Nimzo dominated in 1998 as a chessprogram.
In 1999 Shredder became world champion. Actually its piece values also were a lot higher than 3.25 relative to a pawn, though ofcourse publicly not visible.
Crafty back then - i can't remember, maybe Bob can dig it up.
So i really wonder what you researched.
Vincent