Yes of course when Anthony Cozzie asked me: "What the hell to tune?", around end 2004 for his master thesis, as about every experiment tuning before that in computerchess had failed, i suggested that he should tune material, as i guessed back then that should be able to get tuned well.metax wrote:Where did you get these values for Rybka?diep wrote: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.
Actually I don't believe that bishop pair values of more than maybe +0.7 make sense.
A big problem of course was the huge amounts of system time needed for such an experiment, but i understood Bob would take care for that as he had quite some hardware.
Then it was basically quiet until world champs 2005.
During the world champs Zappa did do a lot better than we all had expected, and the question asked in that cafe by Shay Bushinsky with Anthony also present, i should have treated with a bit more suspicion of course.
Crafty that world champs also played with automatic PSQ values tuned by Anthony.
I was very amazed to see how Crafty in a game against Isichess parked its white knight on a1. Isichess back then was really weak; not very well comparable with the years after that it would get a big eloboost as it seems he cut'n pasted some material values that he found on the net somewhere and also the increased search depth caused by things like LMR are important to mention.
Bob i was told, was very upset about the square a1 having such a clumsy tuning, meanwhile Zappa getting world champion in a clear manner, of course without burying a white knight on a1.
Now Zappa of course like Diep is a slow program in nps relative to what is possible and if you are a programmer like Cozzie of course you're low level quite some better than the average coder in computerchess is.
So during the world champs we wondered about how strong Fruit would be if you would rewrite its code to faster code which as i expected would be exactly factor 2 times faster and also fix a few obvious bugs in evaluation, such as it total overestimating and losing games to too optimistic passed pawn scores and of course especially the material evaluation.
Now short before world champs 2005 as i said again my big nps monster i tried to combine with diep. That was maybe at that point not such a good idea. To quote SMK: "it is difficult to combine 2 different programs with each other". He's right there. Easier is just produce 1 beancounter good in blitz.
Of course somewhere i dropped the remark that Frans Morsch had told me that the big secret of his engines as well as genius was the huge nps they got and that up until late 90s no one realized even how many nps he got.
Anthony must've remembered that.
Anthony must have combined all that brilliantly as i of course have asked him the question: "how comes that Zappa's bitboard functions which no other programmer in CCC uses, as they got a faster alternative, are inside this product?"
Anthonies reaction was: "oh Vasik's brother works here as my collegue, maybe his brother stole my code".
Another question on a specific bitboard bitmask i saw the assembler from i couldn't understand.
Anthony within 20 seconds: "h2 pawn attacks a3, that's a bug, the bitmask is wrong in rybka". That was a bit *too quick*. I didn't even know it was a bitmask.
Anyway. That was the first version, what happened after that is yet another story from which we all only like to know: "Whom pays for it?"
Oh doh, Bishop pair huh.
I emailed a random Russian guy called Alex Trofimov just now he replied:
Oh well let's give it to you with 4 pawns onthe board.
number of White Queen(s) [0..2] : 0
number of Black Queen(s) [0..2] : 0
number of White Rook(s) [0..2] : 1
number of Black Rook(s) [0..2] : 1
number of White Bishop(s) [0..2] : 2
number of Black Bishop(s) [0..2] : 1
number of White Knight(s) [0..2] : 1
number of Black Knight(s) [0..2] : 2
number of White Pawn(s) [0..8] : 4
number of Black Pawn(s) [0..8] : 4
Value in table ==> material = 175 flags = 592
So that's +1.75
Now let's take the full board ok with minimum removed:
number of White Queen(s) [0..2] : 1
number of Black Queen(s) [0..2] : 1
number of White Rook(s) [0..2] : 2
number of Black Rook(s) [0..2] : 2
number of White Bishop(s) [0..2] : 2
number of Black Bishop(s) [0..2] : 1
number of White Knight(s) [0..2] : 1
number of Black Knight(s) [0..2] : 2
number of White Pawn(s) [0..8] : 8
number of Black Pawn(s) [0..8] : 8
Value in Rybka table ==> material = 101 flags = 86
+1.01
It works.
Thanks,
Vincent