Page 1 of 2

ThothFishv1.0

Posted: Sun Mar 24, 2019 7:04 pm
by Damir
From a user on mzchessforum:

Lately i was quite busy and next months wont be better so i decided to upload my compilation of stockfish today. I was planning to make more tests, tune values, maybe add other options but honestly test every set of values needs at least hundred of games and unfortunately i dont have time and resources to do it for now.

So this is ThothFish, my derivative of stockfish. Thoth is of course name of ancient egyptian god of wisdom and magic. With default options it should plays identical like stockfish_19032014, maybe its a tiny slower but its a matter of compilation, i put source files here anyway so everyone can compile it in better way than me because im not good at compiling and my hardware neither.

Funny thing is i dont know c++ or any other programming language, im not a programmer but i observed patches on stockfish testing framework and learn enough to make it work and implement some of my ideas.

OK, what's new in Thothfish? First of all Thothfish has a nice option to check in uci menu - "MagicTacticSolver". I have to warn you, dont try to play whole games with this option checked. "MagicTacticSolver" works only when there is some big positional/material gain or mate; in quiet positions it would make blunders and playing whole game with it brings only bizarre performance. On the other hand "MagicTacticSolver" can do real magic when analyzing complex or zugzwang positions. Should be useful for solving chess puzzles or in correspondence games, it usually see a lot more than any chess engines. Below are examples of few positions, hard for stockfish, but most of them MagicTacticSolver can solve under minute.
8/1pN4r/5pkp/8/5K1p/2P4N/P3Bn2/8 w Bh5+
rk6/p1r3p1/P3B1Kp/1p2B3/8/8/8/8 w - - 0 1 Be7
8/6pp/1K6/N5P1/3N4/8/npn1P3/k7 w - - 0 1 Nb3
7r/K7/5k1n/p3p3/Pp1pPp1p/1PpP1PpP/2P3P1/N1RR1B2 b - - 0 1 Ke7
8/2p1p1p1/2P1P1Pp/P4K2/P7/p2p4/rppP3P/qkn4R w - - a6
8/3P3k/n2K3p/2p3n1/1b4N1/2p1p1P1/8/3B4 w Nf6+

I tested MagicTacticSolver with dozens of positions from fishcook and talkchess and personally trust in its abilities a lot more than in options of tactic solutions from other chess engines/derivatives.

Another thing u notice in uci menu are options from "pawn exchange" to "queen exchange". The bigger values u set (range is from -1000 to 1000, 0 is default) the more stockfish will try to exchange picked piece. For example with 1000 in queen exchange it would try to exchange queens before 20 moves or sooner if possible, analogical with -1000 queen exchange it will sacrfice a lot only to save his queen and opponent's queen on chessboard as long as possible. I think to make it competitive - relative safe range to testing is from -200 to 200, rest is for fun or testing/making opening books.
Logical - the bigger values in all pieces brings more open positions with quick exchanges and negative values brings closed positions. It has a lot of potential because when i was making tests with different sets of values i saw first time many opening playing by stockfish which it would never play without it (exchange options) and whats equally important it could still draw and win games against "normal" stockfish. I believe or could bet that with some values different from zero it has chance to gain some elo over standard stockfish, from results of incomplete tests i noticed better performance with some changed values. As i mentioned on beginning i have no time and resources to make serious tests and change default values, but maybe in future, with another version of ThothFish (if it ll be next version, i cant promise)... - we ll see...

Last thing, u can set contempt from -2000 to 2000, its not only for entertainment purposes, it can be useful when u changed to extreme exchange values. With very low exchange values stockfish would show negative score even as white in initial chess position (because it predicts exchanges in his lines and know it cant avoid all of them) and with all high values it can be too confident - so u have big range of contempt to compensate score.
With small changes u dont have to bother and just leave contempt as it is - 24.

Engine - https://www20.zippyshare.com/v/DSpZduWK/file.html
Source - https://www41.zippyshare.com/v/yHA3lEBu/file.html

Re: ThothFishv1.0

Posted: Mon Mar 25, 2019 9:44 pm
by jmartus
How does it compare in strength vs recent stockfish development?

Re: ThothFishv1.0

Posted: Tue Mar 26, 2019 1:49 am
by tpoppins
jmartus wrote:
Mon Mar 25, 2019 9:44 pm
How does it compare in strength vs recent stockfish development?
Damir wrote:
Sun Mar 24, 2019 7:04 pm
With default options it should plays identical like stockfish_19032014

Re: ThothFishv1.0

Posted: Tue Mar 26, 2019 5:10 am
by carldaman
This is a significant development, imo. We're finally getting a version of SF with a de facto adjustable smart contempt, including the ability to avoid trades, similar to what Komodo offers. A great feature to have and long awaited.

In my test games, it shows it can deliver a mean game, preferring closed positions and slow build-ups, with some very strong endgame play on top of everything else. It even likes the Colle System as white as its preferred opening, lol. Overall its play is very patient, prophylactic, but potent - a nice, almost-human Petrosian-like personality, if you're a fan of that.

A big thanks to the author who took the trouble to develop and release this useful derivative!

Re: ThothFishv1.0

Posted: Thu Mar 28, 2019 8:53 am
by corres
carldaman wrote:
Tue Mar 26, 2019 5:10 am
This is a significant development, imo. We're finally getting a version of SF with a de facto adjustable smart contempt, including the ability to avoid trades, similar to what Komodo offers. A great feature to have and long awaited.
In my test games, it shows it can deliver a mean game, preferring closed positions and slow build-ups, with some very strong endgame play on top of everything else. It even likes the Colle System as white as its preferred opening, lol. Overall its play is very patient, prophylactic, but potent - a nice, almost-human Petrosian-like personality, if you're a fan of that.
A big thanks to the author who took the trouble to develop and release this useful derivative!
I also think these modifications are suitable to make personalities for Stockfish.
But there is no any opportunity to change parameters to the the actual opponent of Stockfish - moreover this would not be correct against opponents.
So if developers of Stockfish want to reach better results against NN engine they would left their ivory tower and beyond making regression tests they would make tests against NN engines too.

Re: ThothFishv1.0

Posted: Fri Mar 29, 2019 6:41 pm
by karger
I tried to d/l Thothfish from the link provided in the 1st post in this thread. The item downloaded from the link is not Thothfish chess engine , it is an installer that tries to install software on your computer , BEWARE , use the link at your own risk. I found a copy of Thothfish chess engine on Chess Diary website. Karger

Re: ThothFishv1.0

Posted: Fri Mar 29, 2019 6:56 pm
by sincerelybrent
karger wrote:
Fri Mar 29, 2019 6:41 pm
I tried to d/l Thothfish from the link provided in the 1st post in this thread. The item downloaded from the link is not Thothfish chess engine , it is an installer that tries to install software on your computer , BEWARE , use the link at your own risk. I found a copy of Thothfish chess engine on Chess Diary website. Karger
Can get it here, too: http://westportchessclub.org/public/com ... s/engines/

Re: ThothFishv1.0

Posted: Sat Mar 30, 2019 1:37 am
by fishpov
Is it possible to have this engine but not in POPCNT because my computer is old.
Thanks.

Re: ThothFishv1.0

Posted: Sat Mar 30, 2019 1:57 am
by dkappe
sincerelybrent wrote:
Fri Mar 29, 2019 6:56 pm
karger wrote:
Fri Mar 29, 2019 6:41 pm
I tried to d/l Thothfish from the link provided in the 1st post in this thread. The item downloaded from the link is not Thothfish chess engine , it is an installer that tries to install software on your computer , BEWARE , use the link at your own risk. I found a copy of Thothfish chess engine on Chess Diary website. Karger
Can get it here, too: http://westportchessclub.org/public/com ... s/engines/
And here: https://github.com/dkappe/ThothFish

Re: ThothFishv1.0

Posted: Sat Mar 30, 2019 8:59 am
by Eduard
Nice engine, thank you! To such settings for stockfish I waited a long time.