FAQ
I am using Rybka 1.1. Should I upgrade to Rybka 1.2?
Yes, we strongly suggest taking a moment to do this. Rybka 1.2 is a major program release, with a number of significant enhancements.
What is improved since Rybka 1.1?
1) Full UCI & UCI2 compliance.
2) Polish added to the cosmetic output of the engine
3) Bug fixes and changes to various undesirable behaviors
4) Improved middlegame evaluation (especially in the area of material imbalances)
5) More efficient search
6) Better handling of some endgames
7) Two new configurable engine parameters
What did not make it into this release?
The next highest-priority items are:
1) Multi-processor support
2) Special engine analysis modes
3) Continued work on middlegame and endgame evaluation
4) Continued work on search efficiency
How much is Rybka's chess strength improved since Rybka 1.1?
Unlike some of the other questions on this list, this one is literally "frequently asked". It is best to let the independent testers measure Rybka's strength.
Can you tell us more about the behavior of Rybka 1.2 in positions with material imbalances?
This is a really tough topic, and still an area where engines lag behind humans. Rybka is now more materialistic in some positions, and less materialistic in others. I am quite confident that the new formulation is at least better than the previous one, but more work is needed.
How should the new engine parameters be used?
"Contempt" should be set to a positive value to instruct Rybka to avoid draws by repetition, and to a negative value to seek them. It is specified in units of centipawns.
"Server Buffer" should be checked when playing on the PlayChess server, which has a bug which causes the engine to be sent slightly inaccurate time information and can cause time losses in really long games. Rybka uses this option to make a small adjustment to her time allocation algorithms. As far as I know, it is not necessary to check this option when playing on other servers.
Can you tell us more about your bug-fixing procedure?
Every bug report I get leads to the creation of one (or more) test cases in my new offline test driver. This driver runs the Rybka engine, and verifies that all of the automated acceptance tests are passed. As a result, while I can't guarantee that Rybka is completely bug-free, I can now at least guarantee that nobody will ever need to send me the same bug report twice.
What do you mean by full UCI & UCI2 compliance?
This is a bit of a misnomer. I mean that Rybka supports all of the commands from the most recent July 2005 UCI specification, ie. UCI_ShowCurrLine, UCI_ShowRefutations, UCI_LimitStrength, etc.
Please note that Rybka does not (yet) support the UCI Chess960 protocol, although this is also specified in that same document.
What happened to the special engine analysis modes?
They just didn't make it into the schedule, and do remain a high priority.
What is next for Rybka?
Please stay tuned for an upcoming announcement in early-to-mid May about future Rybka versions.
Prospective Rybka customers should be aware that Rybka 1 is coming to the end of its cycle, and that Rybka 2 _may_ go on sale as early as June 1, 2006. Those who would like to plan their software purchases are advised to wait until this announcement so that they can make informed decisions.
When will we see a multi-processor version of Rybka?
This is right around the corner - please wait for the announcement mentioned above.
