ProDeo 3.1 - The PESTO version

[Rebel]

PESTO stands for Piece Square Tables Only as described on the Rofchade website by Dutchman Ronald Friederich and later implemented in TSCP by Rodent author Pawel Koziol which gave TSCP an 200 elo boast.

Inspired by this I implemented PESTO in ProDeo (on top of the existing PST's) just for the fun of it and for a 3 days work (one day programming, two days testing) the results (+50 elo) are very good for ProDeo. I therefore can recommend every engine programmer to give it the same try, hence this release.
....

http://rebel13.nl/prodeo/prodeo-3.1.html

[pedrox]

I use the evaluation not only on terminal nodes but also on internal nodes as using only material more margin for pruning does not give me good results.

I have tried to use PeSTO evaluation on each internal node for pruning and the result has not been conclusive, but maybe I don't lose Elo and maybe I gain +5. What I notice is that my engine does not seem faster even though the evaluation is much smaller.

But when I replace my evaluation by PeSTO evaluation I lose about 150 Elo points.

I don't know why this works in Prodeo and not in my engine. I thought that one of the weak parts of my engine was the evaluation, I supposed it was worse than Prodeo and and therefore it seems that it should work easier. So I'm a bit confused.

[pedrox]

It would be interesting to see a Fruit 2.1 with PeSTO evaluation.

[JohnW]

Played a few games between 3.1 and 2.0 @ 1+1 time controls, seems pretty close..

ProDeo 3.1 +5/=11/-4
ProDeo 2.0 +4/=11/-5

[Rebel]

I use the evaluation not only on terminal nodes but also on internal nodes as using only material more margin for pruning does not give me good results.

I have tried to use PeSTO evaluation on each internal node for pruning and the result has not been conclusive, but maybe I don't lose Elo and maybe I gain +5. What I notice is that my engine does not seem faster even though the evaluation is much smaller.

But when I replace my evaluation by PeSTO evaluation I lose about 150 Elo points.

I don't know why this works in Prodeo and not in my engine. I thought that one of the weak parts of my engine was the evaluation, I supposed it was worse than Prodeo and and therefore it seems that it should work easier. So I'm a bit confused.

It's a known fact what works for engine X doesn't have to work for engine Y and vice versa. 4 points comes to mind -

1. I used Pawel's source code for TSCP as found on the TSCP page, pesto.zip.
2. I used the PESTO PST's without the piece values else there will be a conflict with your own piece values.
3. I used the PESTO PST's on top of the PST evaluation in ProDeo, there is some other good stuff in it that I did not want to replace (lose).
4. I noticed the main elo gain came from the evaluation (+45) and little from the search changes, +5 max.

[hgm]

I am not sure what needs to be implemented. Most engines already have Piece-Square tables, often in addition to other evaluation terms, so it seems this is just a matter of tuning the eval parameters they already have. (In particular, setting the weight for all other terms to zero, and tune all the PST values.)

Of course just copying the values from an engine that has optimized them, and where they work excessively well, saves a lot of tuning effort. But the problem is of course that it isn't your own engine anymore. Micro-Max would probably also be 3000+ Elo if I borrowed Stockfish' search and Leela's eval.

[pedrox]

I use the evaluation not only on terminal nodes but also on internal nodes as using only material more margin for pruning does not give me good results.

I have tried to use PeSTO evaluation on each internal node for pruning and the result has not been conclusive, but maybe I don't lose Elo and maybe I gain +5. What I notice is that my engine does not seem faster even though the evaluation is much smaller.

But when I replace my evaluation by PeSTO evaluation I lose about 150 Elo points.

I don't know why this works in Prodeo and not in my engine. I thought that one of the weak parts of my engine was the evaluation, I supposed it was worse than Prodeo and and therefore it seems that it should work easier. So I'm a bit confused.

It's a known fact what works for engine X doesn't have to work for engine Y and vice versa. 4 points comes to mind -

1. I used Pawel's source code for TSCP as found on the TSCP page, pesto.zip.
2. I used the PESTO PST's without the piece values else there will be a conflict with your own piece values.
3. I used the PESTO PST's on top of the PST evaluation in ProDeo, there is some other good stuff in it that I did not want to replace (lose).
4. I noticed the main elo gain came from the evaluation (+45) and little from the search changes, +5 max.

I used the first option. I have tested PeSTO on a TSCP-derived engine (Caligula), so it is even possible to copy the TSCP evaluation directly with copy-paste.

But I understand now, that in ProDeo not all your evaluation has been replaced by PeSTO from TSCP, I understand that you keep things from the evaluation like maybe mobility, king safety ...

The interesting thing about PeSTO if I'm not confused, is that its author with this evaluation (material + pst) already has 3100 Elo points.

https://ccrl.chessdom.com/ccrl/404/cgi/ ... 4-bit_4CPU

[Rebel]

I use the evaluation not only on terminal nodes but also on internal nodes as using only material more margin for pruning does not give me good results.

I have tried to use PeSTO evaluation on each internal node for pruning and the result has not been conclusive, but maybe I don't lose Elo and maybe I gain +5. What I notice is that my engine does not seem faster even though the evaluation is much smaller.

But when I replace my evaluation by PeSTO evaluation I lose about 150 Elo points.

I don't know why this works in Prodeo and not in my engine. I thought that one of the weak parts of my engine was the evaluation, I supposed it was worse than Prodeo and and therefore it seems that it should work easier. So I'm a bit confused.

It's a known fact what works for engine X doesn't have to work for engine Y and vice versa. 4 points comes to mind -

1. I used Pawel's source code for TSCP as found on the TSCP page, pesto.zip.
2. I used the PESTO PST's without the piece values else there will be a conflict with your own piece values.
3. I used the PESTO PST's on top of the PST evaluation in ProDeo, there is some other good stuff in it that I did not want to replace (lose).
4. I noticed the main elo gain came from the evaluation (+45) and little from the search changes, +5 max.

I used the first option. I have tested PeSTO on a TSCP-derived engine (Caligula), so it is even possible to copy the TSCP evaluation directly with copy-paste.

But I understand now, that in ProDeo not all your evaluation has been replaced by PeSTO from TSCP, I understand that you keep things from the evaluation like maybe mobility, king safety ...

Yes, the PESTO evaluation is an add-on to the normal evaluation, solly if that was not clear.

The interesting thing about PeSTO if I'm not confused, is that its author with this evaluation (material + pst) already has 3100 Elo points.

Absolutely amazing, PST only with a good search, conclusion: there must be value is these asymmetrical PST's.

[dkappe]

Did you use the PST values that you shared a few months ago?

[Rebel]

Did you use the PST values that you shared a few months ago?

Can't remember that I shared PST's a couple of months ago, I do remember I once did years ago. You will have to refresh my memory