Balanced-12.ctg is a neutral opening book for engine tests, to be used with the Fritz chess program.
Facts & Infos:
-> 90%* based on 14,400 selected master games from 1985-2006 -> Elo average 2640 (minimum 2300 each, to 90% both 2500+) -> min. 20 moves for wins, min 30 moves for draws -> works best with "normal" AND "Min.games = 3" book options -> maximal variation lenght: 12 full moves (24 plies) -> checked by engines with 200 test variations: in 187/200 both first evals within +/- 0.50 -> contains 129,701 positions. Decompressed file size 9 MByte.
*) 10% of the games database are high quality test games from CCRL and CEGT, collected and rated by N.Pollock: http://hoflink.com/~npollock/chess.html (CCG database) Thanks to the contributors of these games.
The Balanced-12 consists from the 3 files
Balanced-12.ctb Balanced-12.ctg Balanced-12.cto
Unzip the download file to your preferred Fritz book location, i.e. ...\ChessBase\Books. Then choose File/Open/Openings Book... from the menu, or Ctrl-F11.
You can review or change the book usage options by pressing F4. For the Balanced-12, I generally recommend "normal" which will provide the intended variety, AND "Minimum games = 3" (to prevent rare short variations).
The "optimized" setting is suitable for tournaments ONLY. Please do NOT use "optimize" for matches with the Balanced-12, it would result in opening doubles. With the normal setting, there is a small probability that opening doubles can occur in LONG matches, like 30+ games with alternate colors.
Compared to the Xmas2640 book, Balanced-12 contains more variations. But still, some openings which are very rare among Grandmasters, are not included. It shouldn't be a problem if used as intended, whith all engines using the same book.
The Balanced-12 does not yet contain any adjusted move weights nor tournament move settings. Therefore, if you have used it with book learning, you could always retrieve the original version by choosing "Reset Weights..." from the Edit/Openings Book menu.