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.

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Other than that:

1. The opening book has been expanded to 1.786.566 positions.

2. The best way to limit (or cancel) the opening book is to open the book.ini file and set [Book Depth = 0]

3. To turn on the permanent brain (default is off) open the ProDeo.eng file and set [Permanent Brain = on]

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ProDeo 3.1x is a special version with the purpose to tune (analyzed) Polyglot opening books by playing matches at rapid time control. Opening books are never perfect but in a convenient way it's possible to weed out most bad or not so good moves. In the below examples we pitch two equal Polyglot books against each other, book-1 the normal way, book-2 the smart way. The smart way does the following things:

1. The first step checks the score of chosen book move with the score of the previous book move and if the score drops with >= 1.00 that book move won't be played. And if that was the only move available from the book the engine starts to calculate ignoring the book move.

2. The second step investigates the cases when there are more than one book moves available. If the score of the chosen book move is lower than >= 0.50 than the score of the best move, the chosen move is replaced with the move with the best score and finally the new chosen book move is compared with the previous book move -- as above -- but now with the 0.50 margin.

3. Book decisions [1] and [2] are stored in the file book-remark.txt as a guide to make modifications for instance with SCID. Results:

Another test was done with the Komodo book.

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Operation

In a nutshell, pre-installed is cute-chess to run engine-engine matches. When you double click start.bat the third book match (see above) at 2 seconds per move using 4 threads will start. When the match is finished book-remarks.txt is generated.

In more detail, modify start.bat in case you want to use more threads, a different time control or play more games.

ccc -concurrency 4 -engine name=book2 cmd=rebeluci.exe dir=book2 proto=uci -engine name=book1 cmd=rebeluci.exe dir=book1 proto=uci -each tc=40/80 timemargin=90000 -draw movenumber=160 movecount=3 score=100 -resign movecount=5 score=500 -rounds 1000 -repeat -pgnout all.pgn

-concurrency 4   - increase or decrease the number of threads.

-each tc=40/80  - increase or decrease the time control, 40/80 means 40 moves in 80 seconds.

-rounds 1000     - increase or decrease the number of games.

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Remarks

1. The chosen number of 1000 games in principle is good enough for a reliable result considering that in most cases there will be an immense number of double opening lines. With narrow opening books (such as the strong books from

Stefan Zipproth one needs less games, 500, maybe even 250 games. With wide books perhaps more games are needed. Insider knowledge is required.

2. ProDeo isn't Stockfish, as one can see from the 3 matches ProDeo needs time to understand the moves the book is feeding the engine. Use at least a time control with one second calculation time, the more the better.

3. Testing different books, copy analyzed Polyglot books (with POLY) in book1/books and book2/books. Then open book.ini

[Book File = books\ProDeo.bin]

and change the bookname. Do this for book1/book.ini and book2/book.ini and double click start.bat.

4. The score margins 0.50 and 1.00 as mentioned at the beginning can be changed.

[Blunder Margin [1] = 100]     * default is 100 centi pawns
[Blunder Margin [2] = 50]      * default is 50 centi pawns

Also here insider knowledge is important. The ProDeo book is fully analyzed with Stockfish 12 and testing has showed that 100 and 50 are good settings. However a book analyzed with one of the latests Lc0 versions requires much lower settings because (current) Lc0 evaluations are much more conservative than Stockfish 12.

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Knowledge Base is the work of months building a quality Polyglot database with analyzed positions by top engines. The knowledge base is recently updated with the full games of 40 legendary players from Morphy till Carlsen analyzed with Stockfish 12 and since the recent release with Stockfish 13. In total 4 million positions, average elo ~3300. Next we analyzed 25 gambits with Stockfish 13, 7 million positions, average elo ~3300. Currently popular openings are analyzed.

The splashscreen of Baretail can be annoying but it really is the best tail program of its kind. As an alternative you can delete or rename baretail and use a text editor, load knowledge.txt (example) and refresh it whenever you want to see the computer analysis. Note, the engine is the unmodified ProDeo 3.1, no changes.