Houdini 2.0 opening book

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Houdini 2.0 opening book is released. (2011-November-10)

The largest and the strongest book. Contains 65 million positions with computer analysis! Developed by Roger E. Zibell

Buy this product and get an opening book optimized for the playing style of Houdini 2.0. Aside from engine matches, the book can be used in analysis and advanced chess. With this book, you will discover numerous new opening lines in seemingly established variations. It will not disappoint you.

Houdini 2.0 opening book is a new step in opening book development. Several methods were used during the development of this book. Deep computer evaluations were combined with analyzing games played and game statistics from various sources.

If you run engine matches, you will be surprised with the improvements this opening book can cause. The advantage over Rybka4 opening book is overwhelming. Not only does the book know good variations, it intentionally initiates the ones the opponent first considers advantageous for itself, only to later discover its position getting worse rapidly. Many lines are very deeply elaborated (up to 20 moves after leaving known theory). Games are often strategically won by the end of the opening. But it doesn’t mean the opening book tries to lure the opponent into traps that can be ruined with one turn if seen through. When playing with Houdini 2.0 book, the engine gets strategically good positions the opponent can barely oppose and forces it to forgo large opening variations.

If you are an advanced chess player, Houdini 2.0 book is indispensable. Everyone knows that common draws are a disease of the advanced chess. In modern chess, it is very difficult to end the opening with sufficient advantage. The opponents use numerous opening books and spend a lot of time analyzing positions. Modern openings are thoroughly investigated and many unexpected improvements are found. Playing by the book, you will get edgy positions many engines won’t be able to see through quickly. The opponent will have to predict several following turns before their engine can adequately assess the situation. This gives you good odds when playing against so-called operators who just run the infinite analysis and follow the first engine line.

With Houdini 2 opening book, you see more than just moves marked green or red and the percentage of certain moves played. You see additional information with computer evaluations, correspondence game statistics and engine match statistics. With this data you can predict the results a certain move can lead to more precisely.

Finally, the opening book will help tournament players to prepare new variations to use against future opponents.

DVD version
Follow the instructions in the “readme.txt” file on the DVD.

Download version
Updating Aquarium to build 490 is recommended to improve your experience.
To update Rybka Aquarium, follow the link:

To update Houdini Aquarium, follow the link:

Download Houdini_2_Books.exe_dwnl.exe. Run the file and specify the Aquarium installation folder. The installation program will copy the necessary files.

The package includes 3 books:

1) H2 extended - it is the main book for playing different kinds of games.
Recommended for use in tournaments.

2) H2 lite - a reduced book. This book can be used if you want to reduce the number of book moves and to allow the engine to start thinking in games earlier.
H2 lite is recommended for longer time controls.

3) H2 Wide - a more variative book. Use it if you find that opponenents have learnt your lines from H2 extended book. It is also good for advanced chess play.

Extra files:
In addition to the base files you can download the following optional trees (the DVD version installs these trees automatically).

CAP – computer evaluations tree. The CAP tree provided with the Houdini 2.0 opening book is much larger than the one coming with Aquarium. So it is recommended to rewrite the old CAP tree in the Aquarium\Data\ATrees directory (CAP.HSH and CAP.ELM files) with the new ones.

D2M – statistics tree based on a large database. The tree is the same as the one included in the Houdini Aquarium package. You don’t need to install it if you are using Houdini Aquarium as a base for the opening book. If you only have older versions of Aquarium, you may want to update it (located in Aquarium\Data\ATrees\Statistics).

Connecting the Opening Book.

After installing the opening book, you can view it in the Game View by opening the drop-down menu in the tree window and choosing one of the 3 options.

Depending on your display width, choose between H2 Expanded and H2 Lite. For analysis, the H2 Expanded version is recommended.

Assigning Books in the Engine List.
You can set the Houdini 2.0 Opening Book to be used by an engine by default. To do it, choose an engine in the Engines mode and select an opening book (such as H2 Expanded) by clicking on the corresponding cell in the Book column.

Assigning Books for a Match in the Engine List.
You can set certain engines to use certain books right before starting a match between them (Engine Competitions mode) by choosing a book in the Opening Book field (if you choose <own books> , the engine will use the book assigned in the Engines mode table)

Using the Opening Book in Other Interfaces.
(Click to open in a separate window)


Information Shown in the Book

After choosing the book in Game View you can see the following information

  1. Move column. Contains moves marked with different colors. Green means it’s a good move, red means it’s a bad move. If there are no green and red colors for the position, base your choice on statistics or computer evaluations with certain probability.
  2. Engines column. Engine games statistics – the most important field the program bases its choice of move on.
  3. Hugebase column – statistics of games played by human players.
  4. ICCF/Corr column – statistics of correspondence games.
  5. 2010-2011 column – statistics of games played during the last 2 years. It allows you to see if a certain move is popular or is rarely played in actual practice.
  6. CAP column – computer evaluations. Very important information. Gives a general idea of what evaluation will the program get by the end of the opening. But as the final evaluations are made after 1 minute, advanced chess players should test them before ending the opening. In about 10% of variations, a longer analysis can change the CAP evaluation significantly – it is natural for chess, and this is why chess don’t stop its development. The very essence of the game is finding good moves the opponent won’t be able to appreciate to their full extent.
  7. Play% column. A move is chosen with certain probability. The probability distribution for the moves is displayed in the Play% column. To calculate the percentage, the program first takes into account its color, then the value in the Engines column, and finally the CAP evaluation (H2 Lite does not take into account CAP evaluations). Although Houdini 2 book does not use Hugebase, ICCF/Corr and 2010-2011 columns to calculate the probability, they are very useful for analysis. If you don’t like the probability distribution, you can set it manually by pressing ‘=’ and entering the desired value. If the value is set manually for a move, the ‘=’ sign appears in front of the percentage value. In the picture above you can see that the percentages for 1.e4 and 1.d4 are set manually (=50% и =20%)

You can hide and show some of the columns. To do this, choose the Tree tab in the top menu, then select Options in the Configurations section. Tick/untick lines in the Visible column to show/hide a column. You can also edit column captions using the left part of the window. Pay attention that the captions for grouped columns (i.e. columns containing several values) are edited in the window that opens after clicking the “Groups…” button.

To sort the moves by values of a column, click on the column caption. The column used for sorting is marked by a white triangle.

As stated above, you can set the exact probability rate for each move. You can also mark moves green, blue, orange and red using the “2”, “3”, “4” and “5” buttons respectively. Use “8” to temporarily cancel the effect of a move coloring. Keep in mind that green moves take priority and red moves are never played.

Advanced users can also increase/decrease the effect certain columns have on the final choice of a move. To do this, open the dialog window under the Opening book settings button. (detailed guide will become available later).


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