Complex sentence: This is time-consuming as a deep search must be performed for each position, but once this is done, updating the book on the fly is easy-after each game played, all new positions are searched for the best deviation.
Split into simpler sentences: This is time-consuming as a deep search must be performed for each position, but once this is done, updating the book is easy. After each game played, all new positions are searched for the best deviation.