Myrddin 0.87 release

[JVMerlino]

Greetings,

I am happy to announce the release of a new version of Myrddin, v0.87. As always, Myrddin can be downloaded, thanks to the generous hosting by Ron Murawski, at:

http://computer-chess.org/doku.php?id=c ... ddin:index

The main reason for the new version is the implementation of SMP. Expected increase at 1 CPU from the previous version is about 30 ELO. Expected increase from 1 CPU to 4 CPU is about +80-90. Here are the release notes:

-- Added SMP support for up to 16 instances (using processes and shared hash memory -- Very Lazy SMP!) -- only tested up to 4 instances! This use of shared memory for all hash tables (transposition, eval and pawn) means that the reported memory usage may appear to be incorrect depending on what program you use to get the information. Beware!
-- Fixed very embarrassing bug in passer eval calculating the distance between two squares that could cause any number of other issues, even a hang or crash
-- Added support for the "cores" command which changes the number of processes being used when SMP is enabled. The initial value will be based on ini file settings.
-- Added a "tb" command which toggles tablebase support. The initial value will be based on ini file settings.
-- Added "Mate in N" announcements to PV output when applicable
-- Fixed a bug in saving scores near mate to the hash table
-- Fixed a bug in determining valid knight outpost squares
-- Fixed text output bug in kibitzing opening book moves on ICC
-- Fixed a rare bug in determining material draw
-- Fixed a bug in which Myrddin would hang or crash if the '.' command (used by Chessmaster GUI) was sent while Myrddin was pondering
-- Fixed a bug that could cause hash memory allocation to fail if more than 1GB was requested. Thanks to Graham Banks for reporting this issue.

jm

[mar]

Congrats John & good luck!

[Graham Banks]

Good news. Been looking forward to a new Myrddin.

[Adam Hair]

Thanks, John!

[supersharp77]

Thank You for the new release! A rare gem is Myrddin 0.86!!

[Mithu]

Thanks for the info John! My interest is aroused looking at the ELO ratings of the engine and its predecessors.
Can you tell us the style of the engine (if possible)?
At ELO 2350+ is it more of a active/aggressive player or is it a positional/python-like style?
Better still will it be tunable in the long run...?

I am eager to play with it so in case you are not sure of its style I will provide some feedback when I sit down to play.

Thanks for the Engine once again.

[JVMerlino]

Thanks for the info John! My interest is aroused looking at the ELO ratings of the engine and its predecessors.
Can you tell us the style of the engine (if possible)?
At ELO 2350+ is it more of a active/aggressive player or is it a positional/python-like style?
Better still will it be tunable in the long run...?

I am eager to play with it so in case you are not sure of its style I will provide some feedback when I sit down to play.

Thanks for the Engine once again.

Hello Mithu,

I would say that its style of play is "speculative". I've known it to make interesting but questionable sacrifices (typically a piece for two pawns) and to make aggressive pawn moves at the expense of king safety.

I think its weakest point is, in fact, its relative lack of interest in keeping its king safe, and this is probably the next main working point for me -- to rewrite the evaluation.

But I'd be very happy to hear your comments after playing it. Many thanks for your interest!

jm

[JVMerlino]

Thank You for the new release! A rare gem is Myrddin 0.86!!

Thank you very much!

jm