14 December 2010

The Rybka Book

While researching the different computer assisted events listed in Chess of the Future -or- Chess of the Past?, the subject of engine oriented opening books appeared repeatedly. Normally, this isn't something I spend much time on. I would rather analyze the first few moves of a new chess960 position than the 25th move of a topical Najdorf variation. But since I play a dozen or so correspondence games per year using the traditional start position, I have to pay some attention to the evolution of opening books, engine or otherwise.

The computer assisted events use only the traditional start position, so prepared opening books play a key role. The dominant book is the Rybka book, just as the dominant engine is Rybka itself. The Rybka book played a role in the most recent World Championship match, Anand - Topalov, Sofia 2010, in the person of Jiri Dufek, who worked as one of Topalov's seconds. Given that Topalov lost the match, it's not certain whether Dufek's contribution was altogether positive, but we'll find out for sure if he remains on Topalov's team for the forthcoming candidate matches. I did a series on the subject of opening preparation earlier this year,

followed by a couple of short posts on the Sofia match, so the Rybka angle merits a seat at the table.

The Rybka book is sold by both Chessbase and ChessOK (formerly Convekta), and while the book itself appears to be the same, the technical implementation isn't and may only be used with other products sold by the respective companies. I'll quote Chessbase marketing pages as examples in this post, because Chessbase has done a better job of recording its history and there are more pages. If we go back a couple of years, we find Jeroen Noomen doing the Jiri Dufek job.

A couple of years earlier there is a record of the first Rybka book.

Along with details about opening book creation, the interview includes a brief mention of chess960, showing why engines are not particularly strong in chess960 openings.

Q: What do you think about Fischer random chess? A: Interesting experiment, but not exactly my cup of tea! One of the organizers of the Mainz tournament asked me to come to the FRC tournament that is being held, adding ‘don’t worry, you need not take your opening books with you’. So from move one the calculating starts, very boring for me!

Sometime after the release of the Rybka 3 book, Noomen left the Rybka team.

  • 2009-05-19: Rybka wins 17th World Computer Chess Championship, Resumé by Rybka author Vasik Rajlich • Opening book: Nick Carlin handled our opening book, taking advantage of material previously published by Jeroen Noomen, and did really well. All of our book positions were equal or better, and all were complex and offered plenty of winning chances.

    Nick is from the new breed of computer chess opening authors, who rely on systematic, automated methods and on statistical analysis. He uses all of the available resources, from Jeroen's work to Playchess games to Aquarium editing tools to Polyglot. For this event, he made algorithmic innovations in the area of sharpening the book exit points – his aim was to drop Rybka off into rich positions with plenty of winning chances, and to prevent opposing authors from doing the opposite. Judging by the games, these methods work quite well.

    Unfortunately, Nick has decided to take an extended break from computer chess after these events, as the time required to stay on top of everything is just too high for him. Jeroen is also still taking a break after his last book release and has started to apply his skills to the stock market – hopefully he will soon be rich and will then return to what is best in life. All of this should underline just how much work is involved in the book preparation. The responsibility is high, as one mistake can spoil an entire event and wipe out the work of everyone on the team. Modern opening theory is simply a huge load and we will have to think about how to handle it.

And some time later Jiri Dufek took over the position.

  • 2010-05-31: Rybka 4 is here – and stronger than ever • As for the opening book – Jiri Dufek is the author of the Rybka 4 opening book. He's been using Lukas' cluster to analyze and test and this book is much deeper and more accurate than every book which is publicly available right now. Note however that this book will be 'objective' – Jiri's goal has been to find the truth, rather than to find variations which suit Rybka. This is an intentional decision by our team. Our goal is to create objective analysis tools. This is what users want, and it also simplifies Jiri's life somewhat, as he doesn't have to worry about things like how Rybka is evolving.

He recorded his thoughts in a pair of Chessbase articles.

All of this confirms my personal decision to leave engine oriented opening books to the experts. Whether the calculating starts on move one or on move 25, it's all the same for me. I'd rather chew my food myself.

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