Relative Piece Values

[Dave Gomboc]

Corbit is the guy who encouraged the courtcases against me in 1999.

!?!?!? I don't recall anything about this.

Separate question: what do you do for a living now, Vince?

Dave

[Dave Gomboc]

Thanks for defending Dann, yet which
people not working for N*SA is Dann helping then?

How many guys from Europe did he ever help?

Vincent

I don't know, but I know there have been a couple of times where, based on some discussion Dann has been having with some computer chess programmer, Dann has written me to ask about my M.Sc. thesis. My impression is that Dann enjoys computer chess hobby, and generally enjoys helping programmers by sharing ideas amongst the community.

(I am not saying that Dann is alone in wanting to help programmers and share ideas!)

Dave

[Edsel Apostol]

I have the source code for his program and he is telling you the truth.

To verify his claim:
attacks.h ( 430): static const int PcVal[] = {0, 100, 325, 325, 500, 975, 10000};

I can also tell you that these array values are used in computation of eval and also that these values are nowhere changed anywhere in the code base.

I can tell you that when I compile the code it plays exactly like the official released version (it may even be my binary -- I don't know).

So if a better list can cause stronger play then perhaps his program will make a big jump in strength very soon. He's already kicking some serious butt using only one thread. Imagine when it runs fully threaded!

Perhaps even Rybka should be worried about the future.

Thanks Dann. You're right, Twisted Logic 20090105_x64 is your compile. It's the one in CEGT, the one playing online and the one that has played in the CCT.

To Vincent:

I have no reason to lie and to deceit people. Yes my engine is a combination of ideas and techniques I've learned from other open source engines combined with my own but it is not a copy/paste thing.

You realize i'm a very liberal person here?

Other programmers aren't. They encouraged me to post that in order to see your reaction. Good example is the blame i got in the loop list accusation in 2003, whereas i was the guy who said before the world championships to the authors who wanted to raise a protest that it was obvious it was a modified crafty and to me if someone really modifies a lot, then that is quite ok, so i didn't support that protest. Later on during the world champs they still wanted to raise that protest and the reason for it to get banned ou tof the icga tournament is because when the icga generous offered to ship the assistent professor Ernst A Heinz to verify it wasn't a clone, whereas both Fritz Reul and Ernst would be visiting the same math congress anyway, so it would logistically be easy to do this verification (Erdogan Gunes operated List that world champs). Fritz refused this.

A few questions.

a) why ship source code to Dann Corbit and not someone else?

Corbit is the guy who encouraged the courtcases against me in 1999. Note i won all of them, for the second time in februari 2002. It cost me a LOT of money, as you might know in mainland Europe you cannot get back lawyer costs in courtcases; so if people specialized in setting up business constructions just to sue, that costs money. This is why in 2000 pocket fritz and pocket tiger were sooner to release, i had this in 1999 ready (but got courtcases).

b) do you consider yourself a software engineer of computer chess components?

Hi Vincent,

a.) I have sent the source code to Dann Corbit way before these posts. If I remember correctly it was November or December last year. We have worked in fixing a bug in 64 bit where my engine crashes due to a negative ply value that is used as an index in the root. He found the bug and he provided me with a 64 bit compile as I don't have a 64 bit OS here. That was the one I've sent to CEGT and the one we used in the CCT. Dann just verify my claim on the material values I'm using in my engine as you state that what I'm using is different.

About the court cases you've mentioned, I am not aware of it until now. In 1999 I was only 15 years old, knows nothing about C but I'm a school varsity chess player. I discovered computer chess in my first couple of years in College and that was the time of Ruffian.

b.) I have just graduated from College two years ago and is a Computer Engineer. I worked as a College Instructor/Professor for two semesters teaching Computer Science and Information Technology students. Some subjects under me are C/C++ Programming and Systems Analysis and Design. After that I worked as a software engineer in a gaming company, and then a software engineer in another company working with a complex CMMS software. Right now I am working as a software engineer in my second gaming company. Well, judge by yourself if I'm fit to be a software engineer.

I have worked with my engine as a hobby since College, around December 2004, and in the past two years I've learned a lot, programming wise and computer chess theory wise.

[Don]

Most strong program seem to use relative piece values of P:N:B:R:Q of roughly 1:4:4:6:12

I recently did a bunch of runs with roughly 1:4:4:5.5:12 and it did a lot better. Are these what others are using now?

IMHO, It depends a lot what else it is done in evaluation. I think that looking at these values is meaningless. For instance, if you give penalties for lack of mobility of bonuses for increased mobility, it will affect the optimal value of the piece.

Miguel

My program tries to normalize them. For instance if a knight is 350 I try to make it a "typical" knight, not one extremely well posted or very poorly posted.

For the sliders, I give the standard value, but when computing mobility (which is always positive) I also throw in a compensation factor, which is worth N squares of mobility (the "typical" mobility.)

The hope is that if I sum up the "fixed" value of all the pieces, the error will not be biased in either direction. This kind of thing is useful for lazy evaluation, you want to minimize the error.

[Daniel Shawul]

Whether or not I am a useful help with good ideas or an annoying pest full of useless suggestions is a matter of opinion. I am obviously more helpful to a beginner than an expert.

You have certainly annoyed me since forever... oh wait more annoying is the accusations against you