Smaug: a new chess engine based on glaurung

[mcostalba]

* All patches applied to glaurung 2.2 can be found on Smaug's webpage. If those changes are found to be useful they can easily be merged in Glaurung (or in Stockfish)

And they will do for sure

That's what I call "open source" development, were many (lousy coupled) people can contribute to a common goal, in this case improve a chess engine.


Thanks!!!
Marco

[sje]

* After living years with Linux and gcc, I have no idea how to compile smaug on Windows (or on MAC). Fx. which compiler should be used and which compile options should be set to get optimal result? Do I need to make different compiles for different Windows versions? I hope you can give me some hints here or if someone can send me compiled binaries, even better.

Apple's OS/X for Macintosh is OpenBSD on top of a Mach kernel. The free Xcode IDE includes the gcc tools, and those tools can also be used from the command line via the Terminal application.

For example, to build Symbolic on either OS/X or Linux:

Code: Select all

g++ -O3 -Wall -finline-limit=2048 -o Symbolic -lpthread  *.cpp

[mcostalba]

And they will do for sure

Joona your patches are great !!!!!

I am now testing the eval parameters tweaks, I will test separately the null move beta corrections later.

Still not finished but I can't resist posting the results on 1'+0'' games Stockfish with patch vs Stockfish without patch after 667 games out of 1000: +171 -149 =347 +11 ELO !!!!

I am testing on the current development version of Stoskfish and I will post the results as soon as I finish.

The current development version of Stockfish is still not available for public, but given the great stuff you donated to us, if you are interested in it please ask it and I will be glad to send you a private copy.

Thanks again
Marco

[ernest]

+171 -149 =347 +11 ELO !!!!
Marco

Encouraging, but 1 standard deviation error = 9.4 Elo

[zullil]

Smaug is a slightly modified version of Glaurung 2.2

* After living years with Linux and gcc, I have no idea how to compile smaug on Windows (or on MAC). Fx. which compiler should be used and which compile options should be set to get optimal result?

Glaurung was developed on a Mac. Smaug compiles effortlessly on my Mac. For more, simply read the Makefile contained with the Glaurung source code. Use the Intel C compiler (icpc) if you own it; it will produce a much faster binary than gcc will.

Hope this helps.

[Tord Romstad]

For example, to build Symbolic on either OS/X or Linux:

Code: Select all

g++ -O3 -Wall -finline-limit=2048 -o Symbolic -lpthread  *.cpp

In Mac OS X under Leopard, GCC 4.2 is also installed, although the default GCC used is version 4.0. In my experience, GCC 4.2 usually gives slightly faster code. Replace "g++" by "g++-4.2" to try.

A compiler flag worth trying is -mdynamic-no-pic. I don't really know what this flag (which doesn't seem to exist in Linux) does, but it improves the speed slightly for me. Finally, when compiling bitboard programs (like Glaurung, Smaug and Stockfish -- I'm not sure about Symbolic) on a Core 2 Duo Mac, it's important to use the -x86_64 flag. If you omit this, you'll get a 32-bit executable, which is much slower.

Tord

[Tord Romstad]

Smaug is a slightly modified version of Glaurung 2.2

* After living years with Linux and gcc, I have no idea how to compile smaug on Windows (or on MAC). Fx. which compiler should be used and which compile options should be set to get optimal result?

Glaurung was developed on a Mac. Smaug compiles effortlessly on my Mac. For more, simply read the Makefile contained with the Glaurung source code. Use the Intel C compiler (icpc) if you own it; it will produce a much faster binary than gcc will.

The Intel compiler for OS X is not free, but I have it. I'll compile optimized x86-64 binaries of Smaug and Stockfish, and put them on my web site later tonight.

Tord

[Tord Romstad]

Joona,

I'm happy to see this new project! Now when I have no time or desire to improve my own engine, it's nice to see talented guys like you and Marco continue my work. Good luck! I can't promise I won't steal something back from you if and when I return to working on Glaurung.


I think you should check with Marcus Prewarski (the author of the UCI engine Diablo) whether the name is OK, though: Several years ago, he had a chess engine (possibly private) named Smaug. That old program is almost certainly no longer in development, and I doubt that Marcus has any objections against you using the same name, but it's better to be sure.

Tord

[zullil]

The Intel compiler for OS X is not free, but I have it. I'll compile optimized x86-64 binaries of Smaug and Stockfish, and put them on my web site later tonight.

Tord

Another example of why Tord is considered such a nice guy!

[zamar]

Still not finished but I can't resist posting the results on 1'+0'' games Stockfish with patch vs Stockfish without patch after 667 games out of 1000: +171 -149 =347 +11 ELO !!!!

Nice to have someone to test those patches, thanks! Your results look promising, though error bar is still quite wide. Of course I did some tests before publishing Smaug, but I think results are much more reliable when tester and patch writer are different persons! Please post all your results (positive or negative) here.

I am now testing the eval parameters tweaks, I will test separately the null move beta corrections later.

Value NullMoveDeltaMidgame[10] =
{ (Value) -8, (Value) 6, (Value)-15, (Value) 9, (Value) 21,
(Value) 34, (Value) 54, (Value) 59, (Value) 61, (Value) 61}

Value NullMoveDeltaEndgame[10] =
{ (Value) 6, (Value) 0, (Value)-13, (Value) -9, (Value)-35,
(Value) 12, (Value) 24, (Value) 9, (Value) 5, (Value) 5}

if you do patching by hand, please note that first indexes are unused. It was only used in optimization process to get estimate of "random noise". Should have documented this better...

However as pruning stuff is slightly different in Stockfish compared to Glaurung, those values might be suboptimal for Stockfish :/

The current development version of Stockfish is still not available for public, but given the great stuff you donated to us, if you are interested in it please ask it and I will be glad to send you a private copy.

Sure I'm interested of it! Thanks! You can post it to jo3on5a.k7iis6ki@gm8ail.com (remove numbers!). Perhaps I can avoid reinventing the wheel