Glaurung 2.1 is now finally available from my web page. I asked for help in testing and tuning this version a few weeks ago, and I never expected so much enthusiastic help! I have lost count of all the people whom I have sent a development version and have given feedback in form of test results, suggested improvements, bug reports and other observations. A big thanks to all of you! Without you, this Glaurung version would have been released later, and it would have been less strong. Thanks also to Jim Ablett, who compiled my Windows executables.
It is possible, perhaps even likely, that this version is a little stronger than the previous public version (2.0.1), but the Elo fetishists will be disappointed, and are advised to spend their time with other engines. This Glaurung version is optimized for risky and entertaining play, not for maximum strength.
There is a detailed list of changes contained in the Readme.txt file, but the highlights are:
- King safety has finally been added! This is not really entirely new and original: The king safety evaluation has been shamelessly cribbed from another well-known free chess engine, and rewritten and adapted to Glaurung's data structures, with some additions and improvements. The addition of king safety seems to make the program stronger, and more importantly, makes it much more fun to watch and play against. There are also lots of new UCI parameters for configuring the king safety, so those who want even wilder play should be able to get what they want with a bit of tuning work.
- Numerous other evaluation changes (I hesitate to say "improvements", because most of them are poorly tested). Several of the evaluation weights are quite big, giving huge positional scores. Don't be surprised to see scores of +3 or +4 in materially equal positions, or to see Glaurung frequently failing to win with a +5 score.
- More accurate forward pruning conditions in the "super qsearch" (the transitional phase between the main search and the qsearch).
- Lots of new UCI parameters. These should be documented, but I'm too lazy at the moment.