Here you can decide whether or not the computer is allowed to make use of The internal tournament book. The tournament book only contains good variations for Rebel. When the tournament book is turned off only REBEL.MVS (which is a much broader book) will be consulted resulting in a much more varied game.
IMPORTANT!
Always use the tournament book in combination with Rebel's
standard opening book. The Tournament book is just a small selection
(5 Kb) of Rebel's main book with the opening lines we consider best
for Rebel. If you turn on Tournament book and turn off the standard
book then Rebel will actually play with an opening book of only 5 Kb!