A drama manager is an omniscient background agent responsible for guiding players through the story space and delivering an enjoyable and coherent experience. Most previous drama managers only consider the designer's intent. We present a drama manager that uses data-driven techniques to model players and provides personalized guidance in the story space without removing player agency. In order to guide players' experiences, our drama manager manipulates the story space to maximize the probability of the players making choices intended by the drama manager. Our system is evaluated on an interactive storytelling game. Results show that our drama manager can significantly increase the likelihood of the drama manager's desired story continuation.