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  • Rybka 4 DVD

Rybka 4 DVD

Brand:    ChessBase

$74.95 $49.95
(You save $25.00)

Rybka 4 Chess Playing Software

Chess engine "Rybka 4" by Vasik Rajlich

Rybka isn't just a chess program it's a bona fide chess legend. Rybka has been the World Computer Chess Champion since 2007, easily taking on all comers to retain its crown. It's arguably the most lauded, most praised, most talked-about chess engine ever.

What's different and exciting about the new Rybka 4?

* Rybka 4 features the Fritz 12 interface which conforms to the latest Microsoft GUI standards.
* Rybka's search functions are updated and improved, allowing it to key in on promising line and discard unpromising continuations earlier and more accurately than ever before.
* Rybka's new engine provides increased tactical accuracy without sacrificing positional judgment.
* A razor-sharp forced search algorithm means that even shallower search depths provide improved results.

All of these combined improvements mean that Rybka 4 is better, stronger, and laser-accurate in its evaluations than even its legendary predecessors.

For years Rybka has been the uncontested number one in computer chess and since its great breakthrough in 2006 the program has won with remarkable regularity one world title after the other. So that this state of affairs will continue in the future, the Rybka-team gathered around programmer Vasik Rajlich has developed a new version which is even better: Rybka 4 plays more aggressively and more tactically.

During the last two years the engine has been improved in almost all areas. One major theme has been the understanding of the attack on the king. The new Rybka 4 is more precise and reliable than its predecessor. At the same time the search function now operates more quickly and efficiently and the evaluation function delivers even more spot-on judgments.

As for the playing style, Rybka 4 logically continues the development of the past few years. Thanks to further development in the tactical area too, the new Rybka 4 will be indispensable for all those who work and analyze with chess engines. Rybka 4 is delivered with the new user-friendly Fritz 12 interface and contains a database of 1.5 million games and includes Classic membership for for one year.

Today the main use of chess software is interactive analysis. Rybka's superior playing strength helps you to quickly assess a position. But analysis with Rybka 4 is much more than just evaluations and best moves. In the user interface designed by ChessBase, Rybka 4 introduces several ground-breaking new analysis features:

Monte Carlo Analysis in Rybka 4: yields precise evaluations by playing thousands of ultra-fast games in a few minutes in a given position. This is very much like using game result statistics, something human players do when choosing their opening variations. Monte Carlo Analysis can be used in any position, but generally it's most useful in two types of positions:

1) Endgames. Many engines often give high scores to drawn endgames (and sometimes low scores to winning ones). Monte Carlo recognizes fortresses and other no-progress situations. It's also good in Rook endgames, which are another computer problem.

2) Positions. There are games where one side has made a big material sacrifice for slow compensation (i.e. not just tactics). For instance you can find lots of piece sacrifices in famous Grandmaster chess games which no computer will correctly appreciate - but which Monte Carlo gets right.

Deep Rybka 4 Chess Playing Software

Interesting: in the starting position the Monte Carlo Analysis gives a 52.8% win probability for White.

Sampled Search in Rybka 4: gives detailed information about the search process, showing scores and alternative moves in the main line. This is helpful when the program searches for a long time in one position. It lets the users see how the engine is thinking and making its decisions.

Deep Rybka 4 Chess Playing Software

Note that in in the live search you can see that the Rybka engine is working on Kasparov's famous 30.Rxb7 sacrifice, which has not turned up in the engine window yet (it will become the main variation after the next iteration). Note too that the square Chess Informant symbol behind certain moves means that these are forced.

Singular Moves in Rybka 4: are annotated graphically. This indicates situations where only one clearly best move exists.

Look for win in Rybka 4: Whenever you feel that there should be a forced win in a position you can explicitly ask for it. Rybka then searches for a decisive move, considerably faster than in normal analysis.

Deep Rybka 4 Chess Software

New high-resolution 3D Staunton pieces in Rybka 4

Persistent Hash Tables in Rybka 4: Rybka can save its hash tables between analysis sessions to preserve valuable information already accumulated in the search tree.

The author of Rybka, Czech-American International Master Vasik Rajlich, has implemented an extraordinary understanding of dynamic factors into his program. This often results in long-term pawn or exchange sacrifices and an active positional playing style resembling human chess. Rybka scores well in all types of situations but dominates especially in asymmetric positions which arise e.g. from Sicilian systems.

The success of the program stems from dedicated team work: IM Iweta Rajlich, rated 2417, is the main tester; Jeroen Noomen contributes opening theory and tournament preparation; IM Larry Kaufman develops positional algorithms.

The Rykba 4 Opening Book

Rybka 4 Opening Book

The Rybka 4 opening book is a high-class compilation of opening theory. It was developed for the world's strongest chess entity - 100 cores cluster Rybka and chess software program Rybka 4 and will maximize the program's playing strength. The choice of variations in the book is well suited to the style of the program, and the book has been fine-tuned and checked in thousands of games.

The Rybka 4 Book includes 17 million positions and over 700,000 games, which were selected from following sources: TOP human practice, correspondence chess games and computer chess games (up to April 2010). And this is only the starting point: the value of the book lies in over 700 original analysis and move choices, which lead to a re-evaluation in many critical points of modern theory. This makes it useful for tournament and correspondence players alike. The book contains a lot of computer-checked analysis never published anywhere before.

The author of the Rybka 4 book is Jiri Dufek (national master, FIDE 2276, ICCF IM 2579), one of the worldåÔs leading experts in chess opening theory. Jiri Dufek has been on the Rybka team since the summer 2009, and his preparation is used in all official events after this date, which Rykba won. During the World Championship match even Vishy Anand and Veselin Topalov worked as second of Veselin Topalov. In his long chess career he wontheCzech Correspondence Team Chess Championship and wrote together with Roman Chytilek book Beating the French Defence (in Czech only).

Note that Rybka 4 includes a database of one million games, and that the purchase of the program entitles you to one year of access to the chess server Rybka 4 is a UCI engine, with 32 and 64-bit versions included in the package. Rybka can be made the default engine in ChessBase 10.

Want to know more about Rybka? Read our Rybka 4 In-Depth Reportby Steve Lopez

System requirements:
Minimum: Pentium III 1 GHz, 512 MB RAM, Windows Vista, XP (Service Pack 3), DirectX9 graphics card with 256 MB RAM, DVD-ROM drive, Windows-Media Player 9, internet access (, updates and activation).
Recommended: PC Intel Core 2 Quad, 2.4 GHz, 3 GB RAM, Windows Vista or Windows 7, DirectX10 graphics card (or compatible) with 512 MB RAM or more, 100% DirectX10 compatible, sound card, Windows Media Player 11, DVD ROM drive and internet access (, updates and activation). The activation of the program requires internet access.

Write Review

  1. 2758 ELO

    Posted by Brian Morris on Dec 7th 2015

    The openning book purchased separately doesn't help much and you can't even view the 700,000 games that supposedly comes with it. All yes make sure not to order endgame turbo 4 for it because it won't work with it. It only works with fritz 14 and higher.