On novelty driven evolution in Poker

This work asks the question as to whether `novelty as an objective' is still beneficial under tasks with a lot of ambiguity, such as Poker. Specifically, Poker represents a task in which there is partial information (public and private cards) and stochastic changes in state (what card will be dealt next). In addition, bluffing plays a fundamental role in successful strategies for playing the game. On the face of it, it appears that multiple sources of variation already exist, making the additional provision of novelty as an objective unwarranted. Indeed, most previous work in which agent strategies are evolved with novelty appearing as an explicit objective are not rich in sources of ambiguity. Conversely, the task of learning strategies for playing Poker, even under the 2-player case of heads-up Limit Texas Hold'em, is widely considered to be particularly challenging on account of the multiple sources of uncertainty. We benchmark a form of genetic programming, both with and without (task independent) novelty objectives. It is clear that pursuing behavioural diversity, even under the heads-up Limit Texas Hold'em task is central to learning successful strategies. Benchmarking against static and Bayesian opponents illustrates the capability of the resulting Genetic Programming (GP) agents to bluff and vary their style of play.