About a rebel evaluation study

[xr_a_y]

Looking at this http://www.top-5000.nl/eval.htm

It seems :
- PSQT are worth 70 elo
- king safety 43 elo
- mobility 118 elo
- pawn eval (?) 15 elo
- passed pawn 97 elo
- piece pair / outpost / center control 33 elo
- other stuff 63 elo

So evaluation features seems to worth 440 elo

Let's say a depth more in search is worth 60 elo, and BF is 2. Making a x4 speed up lead to another 120 elo.

So starting from a simple, reasonably fast engine around elo 2000, I feel that 2600 is already quite difficult to achieve (rebel / prodeo is indeed around 2700)! How can some engine reach 3000 ? Is it just years and years of fine tuning and speed up adding 5/10 elo each ?

[tomitank]

Yes, tuning is very important, even including search.

Search must also be in balance with eval.
eg:
Aspiration window is significant better with a "perfect" eval. (Score does not fluctuate)

I dont no what use Rebel, but the modern search give lots of Elo.

Threats is more important, than rebel says..if you make that well.

tomitankChess written in JavaScript. JavaScript is ~10x slower than C languages..

Nonetheless the next version it will be over 2600 Elo.
(With manual tuning...machine learning would be better.)

[cdani]

How can some engine reach 3000 ? Is it just years and years of fine tuning and speed up adding 5/10 elo each ?

Yes. Also less than 5 elo patches. For Andscacs maybe I have done 8000-10000 versions since sep 2013.

[Uri Blass]

Looking at this http://www.top-5000.nl/eval.htm

It seems :
- PSQT are worth 70 elo
- king safety 43 elo
- mobility 118 elo
- pawn eval (?) 15 elo
- passed pawn 97 elo
- piece pair / outpost / center control 33 elo
- other stuff 63 elo

So evaluation features seems to worth 440 elo

Let's say a depth more in search is worth 60 elo, and BF is 2. Making a x4 speed up lead to another 120 elo.

So starting from a simple, reasonably fast engine around elo 2000, I feel that 2600 is already quite difficult to achieve (rebel / prodeo is indeed around 2700)! How can some engine reach 3000 ? Is it just years and years of fine tuning and speed up adding 5/10 elo each ?

I think that you cannot do a math like this.

The value of new stuff is dependent on the value of older stuff that you have so there is no meaning to the claim that PST worth 70 elo.

Edit:I can add that the best PST is dependent on the other stuff that you have and is not constant.

Edit 2:I can add that I believe that only piece square table with good search should have already 2600 elo

[zenpawn]

Edit 2:I can add that I believe that only piece square table with good search should have already 2600 elo

I really hope that's not true considering all the work, including eval tuning, I've put into creating an almost 2400-rated engine.

[Uri Blass]

Edit 2:I can add that I believe that only piece square table with good search should have already 2600 elo

I really hope that's not true considering all the work, including eval tuning, I've put into creating an almost 2400-rated engine.

I feel sure it is correct.

I remember that in the past I changed strelka's evaluation to only piece square table evaluation and I believe that I got something that was better than 2400.

It could easily beat Joker that is 2300 elo engine in most games(so I think it was 2400-2500 elo)

http://www.computerchess.org.uk/ccrl/40 ... ker_1_1_14

Note that I did not try to optimize Strelka's piece square table and I believe that strelka's search is also weaker than the search of today top programs.

[zenpawn]

Depressing.

[Greg Strong]

Depressing.

You can say that again!

[xr_a_y]

Wow 2600 just with psqt ... So the search prunings / razorings must be highly tuned. Is there such an opensource engine with a basic evaluation but that is higher than 2500 elo to get some inspiration ?

[cdani]

Wow 2600 just with psqt ... So the search prunings / razorings must be highly tuned. Is there such an opensource engine with a basic evaluation but that is higher than 2500 elo to get some inspiration ?

Take Andscacs or Stockfish and remove most of the stuff in the eval function.